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Run out of butter or eggs? Here’s the science behind substitute ingredients

<p><em><a href="https://theconversation.com/profiles/paulomi-polly-burey-404695">Paulomi (Polly) Burey</a>, <a href="https://theconversation.com/institutions/university-of-southern-queensland-1069">University of Southern Queensland</a></em></p> <p>It’s an all too common situation – you’re busy cooking or baking to a recipe when you open the cupboard and suddenly realise you are missing an ingredient.</p> <p>Unless you can immediately run to the shops, this can leave you scrambling for a substitute that can perform a similar function. Thankfully, such substitutes can be more successful than you’d expect.</p> <p>There are a few reasons why certain ingredient substitutions work so well. This is usually to do with the chemistry and the physical features having enough similarity to the original ingredient to still do the job appropriately.</p> <p>Let’s delve into some common ingredient substitutions and why they work – or need to be tweaked.</p> <p><iframe id="IitfH" class="tc-infographic-datawrapper" style="border: none;" src="https://datawrapper.dwcdn.net/IitfH/1/" width="100%" height="400px" frameborder="0"></iframe></p> <h2>Oils versus butter</h2> <p>Both butter and oils belong to a chemical class called <a href="https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Map%3A_Fundamentals_of_General_Organic_and_Biological_Chemistry_(McMurry_et_al.)/23%3A_Lipids/23.01%3A_Structure_and_Classification_of_Lipids">lipids</a>. It encompasses solid, semi-solid and liquid fats.</p> <p>In a baked product the “job” of these ingredients is to provide flavour and influence the structure and texture of the finished item. In cake batters, lipids contribute to creating an emulsion structure – this means combining two liquids that wouldn’t usually mix. In the baking process, this helps to create a light, fluffy crumb.</p> <p>One of the primary differences between butter and oil is that butter is only about 80% lipid (the rest being water), while <a href="https://www.nutritionadvance.com/types-of-cooking-fats-and-oils/">oil is almost 100% lipid</a>. Oil creates a softer crumb but is still a great fat to bake with.</p> <p>You can use a wide range of oils from different sources, such as olive oil, rice bran, avocado, peanut, coconut, macadamia and many more. Each of these may impart different flavours.</p> <p>Other “butters”, such as peanut and cashew butter, aren’t strictly butters but pastes. They impart different characteristics and can’t easily replace dairy butter, unless you also add extra oil.</p> <h2>Aquafaba or flaxseed versus eggs</h2> <p>Aquafaba is the liquid you drain from a can of legumes – such as chickpeas or lentils. It contains proteins, kind of how egg white also contains proteins.</p> <p>The proteins in egg white include albumins, and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5912395/">aquafaba also contains albumins</a>. This is why it is possible to make meringue from egg whites, or from aquafaba if you’re after a vegan version.</p> <p>The proteins act as a foam stabiliser – they hold the light, airy texture in the product. The concentration of protein in egg white is a bit higher, so it doesn’t take long to create a stable foam. Aquafaba requires more whipping to create a meringue-like foam, but it will bake in a similar way.</p> <p>Another albumin-containing alternative for eggs is <a href="https://foodstruct.com/compare/seeds-flaxseed-vs-egg">flaxseed</a>. These seeds form a thick gel texture when mixed with a little water. The texture is similar to raw egg and can provide structure and emulsification in baked recipes that call for a small amount of egg white.</p> <h2>Lemon plus dairy versus buttermilk</h2> <p>Buttermilk is the liquid left over after churning butter – it can be made from sweet cream, cultured/sour cream or whey-based cream. Buttermilk mostly <a href="https://www.journalofdairyscience.org/article/S0022-0302(06)72115-4/fulltext">contains proteins and fats</a>.</p> <p>Cultured buttermilk has a somewhat tangy flavour. Slightly soured milk can be a good substitute as it contains similar components and isn’t too different from “real” buttermilk, chemically speaking.</p> <p>One way to achieve slightly soured milk is by adding some lemon juice or cream of tartar to milk. Buttermilk is used in pancakes and baked goods to give extra height or volume. This is because the acidic (sour) components of buttermilk interact with baking soda, producing a light and airy texture.</p> <p>Buttermilk can also influence flavour, imparting a slightly tangy taste to pancakes and baked goods. It can also be used in sauces and dressings if you’re looking for a lightly acidic touch.</p> <h2>Honey versus sugar</h2> <p>Honey is a <a href="https://resources.perkinelmer.com/lab-solutions/resources/docs/APP_Analysis-of-Sugars-in-Honey-012101_01.pdf">complex sugar-based syrup</a> that includes floral or botanical flavours and aromas. Honey can be used in cooking and baking, adding both flavour and texture (viscosity, softness) to a wide range of products.</p> <p>If you add honey instead of regular sugar in baked goods, keep in mind that honey imparts a softer, moister texture. This is because it contains more moisture and is a humectant (that is, it likes to hold on to water). It is also less crystalline than sugar, unless you leave it to crystallise.</p> <p>The intensity of sweetness can also be different – some people find honey is sweeter than its granular counterpart, so you will want to adjust your recipes accordingly.</p> <h2>Gluten-free versus regular flour</h2> <p>Sometimes you need to make substitutions to avoid allergens, such as gluten – the protein found in cereal grains such as wheat, rye, barley and others.</p> <p>Unfortunately, gluten is also the component that gives a nice, stretchy, squishy quality to bread.</p> <p>To build this characteristic in a gluten-free product, it’s necessary to have a mixture of ingredients that work together to mimic this texture. Common ingredients used are corn or rice flour, xanthan gum, which acts as a binder and moisture holder, and tapioca starch, which is a good water absorbent and can aid with binding the dough. <!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/202036/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/paulomi-polly-burey-404695">Paulomi (Polly) Burey</a>, Associate Professor (Food Science), <a href="https://theconversation.com/institutions/university-of-southern-queensland-1069">University of Southern Queensland</a></em></p> <p><em>Image credits: Shutterstock</em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/run-out-of-butter-or-eggs-heres-the-science-behind-substitute-ingredients-202036">original article</a>.</em></p>

Food & Wine

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Science finally proves "Money doesn't buy happiness"

<p>A new study has proven that the old adage "money can't buy you happiness" is true. </p> <p>Historically, economic wealth and higher income households are often seen to have an increased level of wellbeing and happiness, with the extra money making way for less stress and more general comfortability. </p> <p>However, researchers from Canada and Spain have concluded this may not be true, with such surveys often including responses from people in industrialised areas only. </p> <p>People in small-scale societies where money does not play a central role in every day life are often excluded from these studies, as the livelihood of residents in these small communities usually depend more on nature. </p> <p>Now, 2,966 people from Indigenous and local communities in 19 locations across the globe have been included in a study, with researchers now finding that societies of Indigenous people and those in small, local communities report living very satisfying lives despite not having a lot of money. </p> <p>The researchers wrote, "The striking aspect of our findings... is that reported life satisfaction in very low-income communities can meet and even exceed that reported at the highest average levels of material wealth provided by industrial ways of life."</p> <p>Researchers concluded the findings are strong evidence that economic growth is not needed to be happy, with only 64 percent of households included in the survey reported having any cash income.</p> <p>Eric Galbraith, lead author of the study, said, "Surprisingly, many populations with very low monetary incomes report very high average levels of life satisfaction, with scores similar to those in wealthy countries."</p> <p>Researchers added that high life satisfaction is shown in these communities "despite many of these societies having suffered histories of marginalisation and oppression."</p> <p>Galbraith added, "I would hope that, by learning more about what makes life satisfying in these diverse communities, it might help many others to lead more satisfying lives while addressing the sustainability crisis."</p> <p><em>Image credits: Shutterstock</em></p>

Money & Banking

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How to make the perfect pavlova, according to chemistry experts

<p><em><a href="https://theconversation.com/profiles/nathan-kilah-599082">Nathan Kilah</a>, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> and <a href="https://theconversation.com/profiles/chloe-taylor-1400788">Chloe Taylor</a>, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a></em></p> <p>The pavlova is a summer icon; just a few simple ingredients can be transformed into a beautifully flavoured and textured dessert.</p> <p>But despite its simplicity, there’s a surprising amount of chemistry involved in making a pavlova. Knowing what’s happening in each step is a sure-fire way to make yours a success.</p> <p>So exactly what does it take to make the perfect pavlova? Let us break it down for you.</p> <h2>Egg whites</h2> <p><a href="https://theconversation.com/eight-cracking-facts-about-eggs-150797">Egg white</a> is basically a mixture of proteins in water. Two of these proteins, ovalbumin and ovomucin, are the key to forming a perfect foamy meringue mixture.</p> <p>Whipping the egg whites agitates the proteins and disrupts their structure, causing them to unfold so the protein’s interior surface is exposed, in a process <a href="https://theconversation.com/sunny-side-up-can-you-really-fry-an-egg-on-the-footpath-on-a-hot-day-172616">known as denaturing</a>. These surfaces then join with one another to trap air bubbles and turn into a stable foam.</p> <p>Egg yolk must be completely removed for this process to work. Yolk is mostly made of fat molecules, which would destabilise the protein network and pop the air bubbles. It only takes a trace amount of fat, or even just a greasy bowl, to disrupt foam formation.</p> <p>You should always whip your egg whites in a clean glass or metal bowl. Plastic bowls are more likely to hold leftover grease.</p> <h2>Sugar</h2> <p>A traditional pavlova uses sugar – a lot of it – to provide texture and flavour. The ratio of sugar to egg white will differ between recipes.</p> <p>The first thing to remember is that adding more sugar will give you a drier and crispier texture, whereas less sugar will lead to a softer and chewier pavlova that won’t keep as long.</p> <p>The second thing is the size of the sugar crystals. The larger they are, the longer they’ll need to be whipped to dissolve, and the greater the chance you will overwork the proteins in your meringue. Powdered icing sugar (not icing mixture) is preferable to caster or granulated sugar.</p> <p>If you do happen to overbeat your meringue (which may end up looking clumpy and watery) you can try to save it by adding another egg white.</p> <h2>Acid</h2> <p>Many pavlova recipes call for adding cream of tartar or vinegar. Cream of tartar is also known as potassium hydrogen tartrate, which you may have seen in the form of crystals at the <a href="https://theconversation.com/louis-pasteurs-scientific-discoveries-in-the-19th-century-revolutionized-medicine-and-continue-to-save-the-lives-of-millions-today-191395">bottom of a wine glass</a>.</p> <p>These acids act as a stabilising agent for the meringue by aiding in the unfolding of the egg white proteins. More isn’t always better, though. Using too much stabiliser can affect the taste and texture, so use it sparingly.</p> <h2>Heat</h2> <p>Cooking a pavlova requires a very slow oven for specific chemical reasons. Namely, egg white proteins gel at temperatures above 60°C, setting the meringue.</p> <p>At higher temperatures a chemical reaction known as the <a href="https://theconversation.com/kitchen-science-from-sizzling-brisket-to-fresh-baked-bread-the-chemical-reaction-that-makes-our-favourite-foods-taste-so-good-58577">Maillard reaction</a> takes place in which proteins and sugars react to form new flavourful compounds. We can thank the Maillard reaction for many delicious foods including <a href="https://theconversation.com/brewing-a-great-cup-of-coffee-depends-on-chemistry-and-physics-84473">roasted coffee</a>, toast and <a href="https://theconversation.com/what-makes-smoky-charred-barbecue-taste-so-good-the-chemistry-of-cooking-over-an-open-flame-184206">seared steak</a>.</p> <p>However, excessive Maillard reactions are undesirable for a pavlova. An oven that’s too hot will turn your meringue brown and give it a “caramelised” flavour. Recipes calling for pavlova to be left in the oven overnight may actually overcook it.</p> <p>At the same time, you don’t want to accidentally undercook your pavlova – especially since uncooked eggs are often responsible for <a href="https://theconversation.com/how-to-avoid-food-borne-illness-a-nutritionist-explains-153185">food poisoning</a>. To kill dangerous bacteria, including salmonella, the pavlova’s spongy centre must reach <a href="https://foodsafety.asn.au/eggs/">temperatures above 72°C</a>.</p> <p>An alternative is to use pasteurised egg whites, which are briefly heated to a very high temperature to kill any pathogens. But this processing may also affect the egg white’s whippability.</p> <h2>Substitute ingredients</h2> <p>People love pavlova, and nobody should have to miss out. Luckily they don’t have to.</p> <p>If you want to <a href="https://theconversation.com/a-taste-for-sweet-an-anthropologist-explains-the-evolutionary-origins-of-why-youre-programmed-to-love-sugar-173197">limit your sugar intake</a>, you can make your meringue using sweeteners such as <a href="https://theconversation.com/whats-the-difference-between-sugar-other-natural-sweeteners-and-artificial-sweeteners-a-food-chemist-explains-sweet-science-172571">powdered erythritol or monk fruit</a>. But, if you do, you may want to add some extra stabiliser such as cornflour, arrowroot starch, or a pinch of xanthan gum to maintain the classic texture.</p> <p>Also, if you want a vegan pavlova, you can turn to the chickpea instead of the chicken! <a href="https://review.jove.com/t/56305/composition-properties-aquafaba-water-recovered-from-commercially">Aquafaba</a> – the water collected from tinned or soaked beans – contains proteins and carbohydrates that give it emulsifying, foaming and even thickening properties. Egg-free pavlova recipes typically replace one egg white with about two tablespoons of aquafaba.</p> <p>And for those of you who don’t do gluten, pavlova can easily be made <a href="https://theconversation.com/gluten-free-diet-is-expensive-socially-challenging-for-those-with-celiac-disease-and-wheat-allergy-155861">gluten-free</a> by using certain stabilising agents.</p> <p>All that’s left is to get creative with your toppings and decide what to do with those leftover yolks!<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/196485/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><a href="https://theconversation.com/profiles/nathan-kilah-599082"><em>Nathan Kilah</em></a><em>, Senior Lecturer in Chemistry, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> and <a href="https://theconversation.com/profiles/chloe-taylor-1400788">Chloe Taylor</a>, Research Fellow - PhD candidate, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a></em></p> <p><em>Image credits: Getty Images</em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/how-to-make-the-perfect-pavlova-according-to-chemistry-experts-196485">original article</a>.</em></p>

Food & Wine

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Worrying news – ozone layer not recovering after all

<p>Alarming news from New Zealand scientists suggests the ozone layer might not be recovering after all, with the problem exacerbated by bushfires, volcanic eruptions and greenhouse gas emissions.</p> <div class="copy"> <p>The research <a href="https://doi.org/10.1038/s41467-023-42637-0" target="_blank" rel="noopener">published</a> in <em>Nature Communications</em> suggests the Antarctic ozone layer has reduced by 26% since 2004, contrary to previous reports of recovery by actions taken under an agreement called the Montreal Protocol. </p> <p>The authors say wildfire and volcanic aerosols together with greenhouse gas emissions probably explain recent setbacks with record large, long-lived ozone holes re-emerging over Antarctica during Spring since 2020.</p> <p>Climate change is influencing the <a href="http://www.bom.gov.au/weather-services/fire-weather-centre/bushfire-weather/index.shtml" target="_blank" rel="noopener">severity and frequency</a> of bushfires.</p> <p>The ozone hole was previously thought to be under repair thanks to a global agreement signed in Montreal, Canada to limit ozone depleting substances. </p> <p>But the paper finds insignificant long-term change in the total ozone column since the early 2000s, “even where significant recovery has previously been reported”.</p> <p>The analysis of daily and monthly ozone changes between 2001 – 2022, show delays in the formation of the ozone hole. While early springtime shows signs of recovery in the ozone layer, this is followed by declines during late September.</p> <p>Researcher and author Hannah Kessenich from the University of Otago says: “by looking at detailed, daily ozone observations from the last 19 years, we find evidence of much less ozone in the centre of the Antarctic ozone hole compared to 19 years ago. This means that the hole has not only remained large in area, but it has also become deeper (i.e. has less ozone) throughout most of Antarctic spring.”</p> <p>But Atmospheric scientist, Dr Martin Jucker from the University of NSW is not convinced by the results of the study.</p> <p>He says: “Their results rely heavily on the large ozone holes we have seen in 2020-2022. However, existing literature has already found reasons for these large ozone holes: Smoke from the 2019 bushfires and a volcanic eruption (La Soufriere), as well as a general relationship between the polar stratosphere and El Niño Southern Oscillation […] The years 2020-22 have seen a rare triple La Niña, but this relationship is never mentioned in the study.”  </p> <p><a href="https://cosmosmagazine.com/earth/earth-sciences/ozone-hole-among-largest-on-record/">This Spring</a>, the European Space Agency reported yet another large ozone hole had formed, among the biggest on record.</p> <p>The layer of ozone high in the atmosphere protects the Earth from ultraviolet (UV) radiation from the Sun. Ozone depletion exposes people, particularly in the Southern Hemisphere, to a higher risk of skin cancer.</p> <p><em>Image credits: Getty Images</em></p> <div> <p align="center"><noscript data-spai="1"><em>&amp;lt;img decoding="async" fetchpriority="high" class="aligncenter size-full wp-image-198773" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2023/11/Cosmos-Catch-Up-embed_728x150-1.jpg" data-spai-egr="1" alt="Sign up to our weekly newsletter" width="600" height="154" title="worrying news - ozone layer not recovering after all 2"&amp;gt;</em></noscript></p> </div> <p><em><!-- Start of tracking content syndication. Please do not remove this section as it allows us to keep track of republished articles --> <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=288486&amp;title=Worrying+news+%26%238211%3B+ozone+layer+not+recovering+after+all" width="1" height="1" loading="lazy" aria-label="Syndication Tracker" data-spai-target="src" data-spai-orig="" data-spai-exclude="nocdn" /></em><em><a href="https://cosmosmagazine.com/earth/climate/ozone-layer-not-recovering/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/petra-stock/">Petra Stock</a>. </em></div>

Travel Trouble

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Sweet secrets – the science of keeping good news hush hush

<p>Most people keep secrets, and staying hush about good news – like pregnancy, presents, proposals and promotions – tends to be freely chosen, enjoyable and energising according to new research.</p> <div class="copy"> <p>Conventional wisdom holds that secrecy is a burden, and good news is <a href="https://cosmosmagazine.com/health/body-and-mind/seeing-emotions/">meant to be shared</a>. But Australian and United States researchers <a href="https://dx.doi.org/10.1037/pspa0000352" target="_blank" rel="noopener">publishing</a> in the <em>Journal of Personality and Social Psychology</em> investigated the effects of keeping positive news to one’s self, finding the motivations and effects are quite different to other types of secrets.</p> <p>Associate Professor Katharine Greenaway researches <a href="https://cosmosmagazine.com/people/society/are-sciences-equal/">social psychology</a> at the University of Melbourne and is an author of the paper. She tells <em>Cosmos</em>: “secrecy is extremely common – on average, 97% of people are keeping a secret right now.” </p> <p>“It’s obviously fascinating to know, people’s secrets, and why they keep them,” she says. </p> <p>Greenaway adds studying secrecy is “really interesting theoretically because we’re social creatures. From our evolutionary past, we’ve always had to be social, we’ve had to communicate in order to co-operate. So, from that perspective it’s really interesting, why would we ever want to keep information from other people? […] It’s particularly interesting why we would keep positive information from others.” </p> <p>Across 5 different experiments involving 2,500 participants the researchers tested different elements of positive secrecy: the effect of secret and non-secret good news; deliberately keeping news secret for personal reasons compared to external reasons ; and the effects of positive secrets compared to other kinds of secrets.</p> <p>“Positive secrets, we’ve found, tend to be the types of secrets people choose freely, and they actually quite enjoy keeping,” Greenaway says.</p> <p>In one study, involving 194 people, participants were provided with a list of 38 common categories of good news, such as: pregnancy; won something; new possession; financial windfall; family news; and self-development. They were asked to indicate which items were relevant, and any they were keeping secret.</p> <p>On average, participants held 14 to 15 pieces of good news, keeping 5 to 6 positive items to themselves.</p> <p>A second study tested motivation. A new group of 600 participants in committed relationships were asked to imagine a plausible piece of good news (from the list of common good news). </p> <p>They were randomly assigned to imagine either: deciding to keep the news secret until they chose share it with their partner, or the information remaining unknown due to external factors like being in meetings all day. For a further group, no reason was specified for not sharing the news. Participants were then asked about how “tired, depleted, weak, passive, active, invigorated, strong, energized, awake and alert, and alive they felt” on a scale from not at all ‘1’ to very much ‘7’.</p> <p>When people elected to keep a piece of good news private, they felt energised. But when external factors got in the way of sharing information, they felt fatigued.</p> <p><iframe title="People are Seriously becoming Friends with their Robotic Vacuums" src="https://omny.fm/shows/huh-science-explained/people-are-seriously-becoming-friends-with-their-r/embed?in_playlist=podcast&amp;style=Cover" width="100%" height="180" frameborder="0"></iframe></p> <p>Three further experiments tested the effect of positive or negative secrets. Finding positive secrets were more likely to be kept for personal reasons, freely chosen, generating greater feelings of energy.</p> <p>“When people keep a positive secret as opposed to a different type of secret, they tend to have relatively more intrinsic motivation for doing so. Intrinsic motivation is associated with feeling like something is really important, personally valuable to you. And also enjoyable,” says Greenaway.</p> <p>“If you’ve kept a negative secret, often you’re worried about what would happen if that secret got out […] you feel as though that’s something that’s being imposed on you, as opposed to something that you’re freely choosing to keep secret from others.”</p> <p>Prior research has mostly focused on negative secrets, suggesting secrecy can be harmful.</p> <p>In contrast, this new research suggests holding on to positive news is more likely to be freely chosen, for personal reasons, and can be more energising than sharing the information.</p> <p><em>Image credits: Getty Images </em></p> <div> <p align="center"><noscript data-spai="1"><em>&amp;lt;img decoding="async" fetchpriority="high" class="aligncenter size-full wp-image-198773" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2023/11/Cosmos-Catch-Up-embed_728x150-1.jpg" data-spai-egr="1" alt="Sign up to our weekly newsletter" width="600" height="154" title="sweet secrets - the science of keeping good news hush hush 2"&amp;gt;</em></noscript></p> </div> <p><em><!-- Start of tracking content syndication. Please do not remove this section as it allows us to keep track of republished articles --> <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=288402&amp;title=Sweet+secrets+%26%238211%3B+the+science+of+keeping+good+news+hush+hush" width="1" height="1" loading="lazy" aria-label="Syndication Tracker" data-spai-target="src" data-spai-orig="" data-spai-exclude="nocdn" /></em><em><a href="https://cosmosmagazine.com/people/social-sciences/sweet-secrets-science/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/petra-stock/">Petra Stock</a>. </em></div>

Mind

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Can coffee help you avoid weight gain? Here’s what the science says

<p><em><a href="https://theconversation.com/profiles/lauren-ball-14718">Lauren Ball</a>, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/emily-burch-438717">Emily Burch</a>, <a href="https://theconversation.com/institutions/southern-cross-university-1160">Southern Cross University</a></em></p> <p>Coffee is well recognised as having a positive impact on long-term health. Drinking the equivalent of three to four cups of instant coffee a day <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5696634/">reduces the risk</a> of many health conditions including heart disease, type 2 diabetes and some cancers.</p> <p>Most people gain <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4984841/">small amounts of weight</a> each year as they age. But can coffee help prevent this gradual weight gain?</p> <p>A group of researchers examined whether drinking an extra cup of coffee a day – or adding sugar, cream or a non-dairy alternative – resulted in more or less weight gain than those who didn’t adjust their intake.</p> <p>Their <a href="https://www.sciencedirect.com/science/article/abs/pii/S0002916523661702">research</a> (currently a pre-proof, which means it has been peer reviewed but is yet to undergo the final formatting and copyediting) found a modest link between coffee and gaining less weight than expected.</p> <p>People who drank an extra cup of coffee a day gained 0.12 kg less weight than expected over four years. Adding sugar resulted in a fraction more (0.09 kg) weight gain than expected over four years.</p> <h2>How was the study conducted? What did it find?</h2> <p>Researchers combined data from three large studies from the United States: two <a href="https://nurseshealthstudy.org">Nurses’ Health Studies</a> from 1986 to 2010, and from 1991 to 2015, and a <a href="https://www.hsph.harvard.edu/hpfs/about-the-study/">Health Professional Follow-up study</a> from 1991 to 2014.</p> <p>The Nurses’ Health Studies are two of the largest cohort studies, with more 230,000 participants, and investigates chronic disease risks for women. The Health Professional Follow-up study involves more than 50,000 male health professionals and investigates the relationship between diet and health outcomes.</p> <p>Participants in all three studies completed a baseline questionnaire, and another questionnaire every four years to assess their food and drink intake. Using the combined datasets, researchers analysed changes in coffee intake and changes in the participants’ self-reported weight at four-year intervals.</p> <p>The average four year weight-gains for the nurses’ studies were 1.2kg and 1.7kg, while participants in the health professionals study gained an average of 0.8kg.</p> <p>The researchers found that increasing unsweetened caffeinated or decaffeinated coffee intake by one cup a day was associated with a weight gain that was 0.12 kg less than expected over four years.</p> <p>Adding creamer (milk) or a non-dairy alternative did not significantly affect this weight change.</p> <p>However, adding sugar (one teaspoon) to coffee was associated with a weight gain that was 0.09 kg more than expected over four years.</p> <p>These associations were stronger in participants who were younger and had a higher body mass index at the beginning of the studies.</p> <h2>What are the pros and cons of the study?</h2> <p>This study is unique in two ways. It had a very large sample size and followed participants for many years. This adds confidence that the associations were real and can likely be applied to other populations.</p> <p>However, there are three reasons to be cautious.</p> <p>First, the findings represent an <em>association</em>, not <em>causation</em>. This means the study does not prove that coffee intake is the true reason for the weight change. Rather, it shows the two changes were observed together over time.</p> <p>Second, the findings around weight were very modest. The average four-year weight gain averted, based on one cup of coffee, was 0.12 kilograms, which is about 30 grams per year. This amount may not be a meaningful change for most people looking to manage weight.</p> <p>Finally, this analysis did not consider the variability in the amount of caffeine in coffee (which we <a href="https://pubmed.ncbi.nlm.nih.gov/17412475/">know can be high</a>), it just assumed a standard amount of caffeine per cup.</p> <h2>How could coffee help with weight management?</h2> <p>Caffeine is a natural stimulant which has been <a href="https://www.sciencedirect.com/science/article/pii/S0149763416300690">shown to</a> temporarily reduce appetite and increase alertness. This may help to feel less hungry for a short period, potentially leading to reduced energy intake.</p> <p>Some people consume coffee before exercise as a stimulant to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7777221/">improve their workout performance</a> – if a workout is more effective, more energy may be expended. However, the benefit is largely thought to be short-lived, rather than long-term.</p> <p>Caffeine has also been <a href="https://www.sciencedirect.com/science/article/pii/S0271531720304449">shown to</a> speed up our metabolism, causing more energy to be burned while resting. However, this effect is relatively small and is not a suitable substitute for regular physical activity and a healthy diet.</p> <p>Finally, coffee has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4725310/">mild diuretic effect</a>, which can lead to temporary water weight loss. This is water loss, not fat loss, and the weight is quickly regained when you re-hydrate.</p> <h2>Is it worth trying coffee for weight loss?</h2> <p>Losing weight can be influenced by various factors, so don’t get too enthusiastic about the coffee-weight link highlighted in this new study, or increase your coffee intake to unreasonable levels.</p> <p>Most adults can safely consume around <a href="https://www.healthdirect.gov.au/caffeine">400mg</a> of caffeine a day. That’s the equivalent of two espressos or four cups of instant coffee or eight cups of tea.</p> <p>If you are pregnant or breastfeeding, it is important to talk to your doctor before increasing your caffeine intake, because caffeine can be passed through to your growing baby.</p> <p>If you need individualised weight guidance, talk to your GP or visit an <a href="https://member.dietitiansaustralia.org.au/Portal/Portal/Search-Directories/Find-a-Dietitian.aspx">accredited practising dietitian</a>. <!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/214954/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/lauren-ball-14718">Lauren Ball</a>, Professor of Community Health and Wellbeing, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/emily-burch-438717">Emily Burch</a>, Dietitian, Researcher &amp; Lecturer, <a href="https://theconversation.com/institutions/southern-cross-university-1160">Southern Cross University</a></em></p> <p><em>Image credits: Getty Images</em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/can-coffee-help-you-avoid-weight-gain-heres-what-the-science-says-214954">original article</a>.</em></p>

Body

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The science of dreams and nightmares – what is going on in our brains while we’re sleeping?

<p><em><a href="https://theconversation.com/profiles/drew-dawson-13517">Drew Dawson</a>, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a> and <a href="https://theconversation.com/profiles/madeline-sprajcer-1315489">Madeline Sprajcer</a>, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a></em></p> <p>Last night you probably slept for <a href="https://www.sciencedirect.com/science/article/pii/S2352721816301292">seven to eight hours</a>. About one or two of these was likely in deep sleep, especially if you’re young or physically active. That’s because <a href="http://apsychoserver.psych.arizona.edu/jjbareprints/psyc501a/readings/Carskadon%20Dement%202011.pdf">sleep changes with age</a> and <a href="https://www.hindawi.com/journals/apm/2017/1364387/">exercise</a> affects brain activity. About three or four hours will have been spent in light sleep.</p> <p>For the remaining time, you were likely in rapid eye movement (REM) sleep. While this is not the only time your brain is potentially dreaming – we also dream during other sleep stages – it is the time your brain activity is most likely to be recalled and reported when you’re awake.</p> <p>That’s usually because either really weird thoughts or feelings wake you up or because the last hour of sleep is nearly all <a href="https://www.researchgate.net/profile/Elizaveta-Solomonova/publication/320356182_Dream_Recall_and_Content_in_Different_Stages_of_Sleep_and_Time-of-Night_Effect/links/5a707bdb0f7e9ba2e1cade56/Dream-Recall-and-Content-in-Different-Stages-of-Sleep-and-Time-of-Night-Effect.pdf">REM sleep</a>. When dreams or your alarm wake you, you’re likely coming out of dream sleep and your dream often lingers into the first few minutes of being awake. In this case you remember it.</p> <p>If they’re strange or interesting dreams, you might tell someone else about them, which may further <a href="https://link.springer.com/article/10.1007/s00426-022-01722-7">encode</a> the dream memory.</p> <p>Dreams and nightmares are mysterious and we’re still learning about them. They keep our brains ticking over. They wash the thoughts from the day’s events at a molecular level. They might even help us imagine what’s possible during our waking hours.</p> <h2>What do scientists know about REM sleep and dreaming?</h2> <p>It’s really hard to study dreaming because people are asleep and we can’t observe what’s going on. Brain imaging has indicated certain <a href="https://www.sciencedirect.com/science/article/pii/S1087079216300673#sec3">patterns of brain activity</a> are associated with dreaming (and with certain sleep stages where dreams are more likely to occur). But such studies ultimately rely on self-reports of the dream experience.</p> <p>Anything we spend so much time doing probably serves multiple ends.</p> <p>At the basic physiological level (indicated by <a href="https://www.sciencedirect.com/science/article/pii/S1053810021001409">brain activity, sleep behaviour and studies of conciousness</a>), all mammals dream – even the platypus and echidna probably experience something similar to dreaming (provided they are at the <a href="https://www.wired.com/2014/07/the-creature-feature-10-fun-facts-about-the-echidna/#:%7E:text=It%20was%20long%20thought%20that,re%20at%20the%20right%20temperature.">right temperature</a>). Their brain activity and sleep stages align to some degree with human <a href="https://www.sciencedirect.com/science/article/pii/S1053810021001409#b0630">REM sleep</a>.</p> <p>Less evolved species do not. Some <a href="https://www.sciencedirect.com/science/article/pii/S2468867319301993#sec0030">jellyfish</a> – who do not have a brain – do experience what could physiologically be characterised as sleep (shown by their posture, quietness, lack of responsiveness and rapid “waking” when prompted). But they do not experience the same physiological and behavioural elements that resemble REM dream sleep.</p> <p>In humans, REM sleep is thought to occur cyclically every 90 to 120 minutes across the night. It prevents us from sleeping too deeply and being <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4972941/">vulnerable to attack</a>. Some scientists think we dream in order to stop our brains and bodies from getting too cold. Our core body temperature is typically <a href="https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(22)00210-1/fulltext">higher while dreaming</a>. It is typically easier to <a href="https://www.tandfonline.com/doi/pdf/10.2147/NSS.S188911">wake from dreaming</a> if we need to respond to external cues or dangers.</p> <p>The brain activity in REM sleep kicks our brain into gear for a bit. It’s like a periscope into a more conscious state, observing what’s going on at the surface, then going back down if all is well.</p> <p>Some evidence suggests “fever dreams” are far less common than we might expect. We actually experience <a href="https://www.frontiersin.org/articles/10.3389/fpsyg.2020.00053/full">far less REM sleep</a> when we have a fever – though the dreams we do have tend to be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3830719/">darker in tone and more unusual</a>.</p> <p>Spending less time in REM sleep when we’re feverish might happen because we are far less capable of regulating our body temperature in this stage of sleep. To protect us, our brain tries to regulate our temperature by “skipping” this sleep stage. We tend to have fewer dreams when the weather is hot <a href="https://www.tandfonline.com/doi/abs/10.1080/23744731.2020.1756664">for the same reason</a>.</p> <h2>A deep-cleaning system for the brain</h2> <p>REM sleep is important for ensuring our brain is working as it should, as indicated by studies using <a href="https://www.cell.com/current-biology/pdf/S0960-9822(17)31329-5.pdf">electoencephalography</a>, which measures brain activity.</p> <p>In the same way deep sleep helps the body restore its physical capacity, dream sleep “<a href="https://www.cell.com/current-biology/pdf/S0960-9822(17)31329-5.pdf">back-flushes</a>” our neural circuits. At the molecular level, the chemicals that underpin our thinking are bent out of shape by the day’s cognitive activity. Deep sleep is when those chemicals are returned to their unused shape. The brain is “<a href="https://www.science.org/doi/abs/10.1126/science.1241224">washed</a>” with cerebrospinal fluid, controlled by the <a href="https://theconversation.com/on-your-back-side-face-down-mice-show-how-we-sleep-may-trigger-or-protect-our-brain-from-diseases-like-als-181954">glymphatic system</a>.</p> <p>At the next level, dream sleep “tidies up” our recent memories and feelings. During <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC534695/">REM sleep</a>, our brains consolidate procedural memories (of how to do tasks) and emotions. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC534695/">Non-REM sleep</a>, where we typically expect fewer dreams, is important for the consolidation of episodic memories (events from your life).</p> <p>As our night’s sleep progresses, we produce more cortisol - the <a href="https://psycnet.apa.org/record/2005-01907-021">stress hormone</a>. It is thought the amount of cortisol present can impact the type of memories we are consolidating and potentially the types of dreams we have. This means the dreams we have later in the night may be <a href="https://learnmem.cshlp.org/content/11/6/671.full.pdf">more fragmented or bizarre</a>.</p> <p>Both kinds of sleep help <a href="https://www.researchgate.net/profile/Jb-Eichenlaub/publication/313545620_Daily_Life_Experiences_in_Dreams_and_Sleep-Dependent_Memory_Consolidation/links/5c532b0ba6fdccd6b5d76270/Daily-Life-Experiences-in-Dreams-and-Sleep-Dependent-Memory-Consolidation.pdf?ref=nepopularna.org">consolidate</a> the useful brain activity of the day. The brain also discards less important information.</p> <h2>Random thoughts, rearranged feelings</h2> <p>This filing and discarding of the day’s activities is going on while we are sleeping. That’s why we often dream about things that happen <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0264574">during the day</a>.</p> <p>Sometimes when we’re rearranging the thoughts and feelings to go in the “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3921176/">bin</a>” during sleep, our level of consciousness allows us to experience awareness. Random thoughts and feelings end up all jumbled together in weird and wonderful ways. Our awareness of this process may explain the bizarre nature of some of our dreams. Our daytime experiences can also fuel nightmares or anxiety-filled dreams after a <a href="https://www.sleepfoundation.org/dreams/how-trauma-can-affect-dreams">traumatic event</a>.</p> <p>Some dreams appear to <a href="https://rai.onlinelibrary.wiley.com/doi/pdfdirect/10.1111/j.1467-9655.2010.01668.x">foretell the future or carry potent symbolism</a>. In many societies dreams are believed to be a window into an <a href="https://digitalcommons.ciis.edu/cgi/viewcontent.cgi?article=1050&amp;context=ijts-transpersonalstudies">alternate reality</a> where we can envisage what is possible.</p> <h2>What does it all mean?</h2> <p>Our scientific understanding of the thermoregulatory, molecular and basic neural aspects of dreaming sleep is <a href="https://www.nature.com/articles/nrn2716">good</a>. But the psychological and spiritual aspects of dreaming remain largely hidden.</p> <p>Perhaps our brains are wired to try and make sense of things. Human societies have always interpreted the random – birds wheeling, tea leaves and the planets – and looked for <a href="https://brill.com/display/book/edcoll/9789047407966/B9789047407966-s003.xml">meaning</a>. Nearly every human society has regarded dreams as more than just random neural firing.</p> <p>And the history of science tells us some things once thought to be magic can later be understood and harnessed – for better or worse.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/210901/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><a href="https://theconversation.com/profiles/drew-dawson-13517"><em>Drew Dawson</em></a><em>, Director, Appleton Institute, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a> and <a href="https://theconversation.com/profiles/madeline-sprajcer-1315489">Madeline Sprajcer</a>, Lecturer in Psychology, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a></em></p> <p><em>Image credits: Shutterstock</em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/the-science-of-dreams-and-nightmares-what-is-going-on-in-our-brains-while-were-sleeping-210901">original article</a>.</em></p>

Mind

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Does it matter what time of day I eat? And can intermittent fasting improve my health? Here’s what the science says

<p><em><a href="https://theconversation.com/profiles/frederic-gachon-1379094">Frederic Gachon</a>, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/meltem-weger-1408599">Meltem Weger</a>, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a></em></p> <p>Early hunter-gatherers faced long periods of fasting. Their <a href="https://pubmed.ncbi.nlm.nih.gov/35834774/">access to food</a> relied on successful hunting, fishing, and the availability of wild plants.</p> <p>Over time, the development of modern agriculture and the transition to industrialised societies <a href="https://pubmed.ncbi.nlm.nih.gov/35834774/">changed our regular eating patterns</a>, shifting our dinner time to later in the day to accommodate work schedules.</p> <p>Today, with access to an abundance of food, we rarely experience prolonged periods of fasting, except for weight loss or religious practices. It’s <a href="https://pubmed.ncbi.nlm.nih.gov/26411343/">now common</a> to have four or more meals a day, with the most calories consumed later in the day. Frequent snacking is also common, over a window of around 15 hours.</p> <p>However, research increasingly shows our health is not only affected by what and how much we eat, but also <em>when</em> we eat. So what does this mean for meal scheduling? And can intermittent fasting help?</p> <h2>Our body clock controls more than our sleep</h2> <p>Our internal biological timekeeper, or circadian clock, regulates many aspects of our physiology and behaviour. It tells us to be awake and active during the day, and <a href="https://theconversation.com/does-it-matter-what-time-i-go-to-bed-198146">rest and sleep</a> during the night. It can also tell us the best time to eat.</p> <p>Our body is biologically prepared to have food during the day. Food digestion, nutrient uptake and energy metabolism is optimised to occur when we’re supposed to be active and eating.</p> <p>Working against this default stage, by regularly eating when we’re supposed to sleep and fast, can compromise these processes and impact our health. <a href="https://pubmed.ncbi.nlm.nih.gov/31813351/">Erratic eating patterns</a>, including late-night meals, have been linked to <a href="https://pubmed.ncbi.nlm.nih.gov/36198293/">weight gain</a> and a greater risk of metabolic disease.</p> <p>Shift-workers, for example, and people who work evening, night or rotating shifts, have a <a href="https://theconversation.com/why-does-night-shift-increase-the-risk-of-cancer-diabetes-and-heart-disease-heres-what-we-know-so-far-190652">higher risk</a> of obesity, heart disease and diabetes.</p> <p>But adopting an eating pattern that aligns with our circadian rhythm can reduce these risks.</p> <h2>So can intermittent fasting help?</h2> <p>Nutritional interventions are increasingly focused not only on “what” we eat but also “when”. Intermittent fasting is one way to restrict the timing, rather than the content, of what we eat.</p> <p>There are <a href="https://pubmed.ncbi.nlm.nih.gov/35834774/">several types</a> of intermittent fasting, one of which is time-restricted eating. This means eating all our calories in a consistent 8-12 hour, or even shorter, interval each day.</p> <p>But is it backed by evidence?</p> <p>Most of what we know today about intermittent fasting and time-restricted eating is from <a href="https://pubmed.ncbi.nlm.nih.gov/35834774/">mouse studies</a>, which demonstrate remarkable weight loss and overall health benefits associated with these types of dietary interventions.</p> <p>However, some aspects of mouse physiology can be different to humans. Mice need to eat more frequently than humans and even a short period of fasting has a more significant physiological impact on mice. One day of fasting in mice leads to a 10% <a href="https://www.sciencedirect.com/science/article/pii/S2212877820301320">loss of body weight</a>, whereas humans would need to fast for 14 days to achieve <a href="https://pubmed.ncbi.nlm.nih.gov/30881957/">similar results</a>. This makes a direct translation from mice to humans more complicated.</p> <p>While health benefits of <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2623528">intermittent fasting</a> and <a href="https://www.nejm.org/doi/full/10.1056/NEJMoa2114833">time-restricted eating</a> have also been observed in humans, the findings in respect of weight loss are less clear. Current data suggest only modest, if any, weight loss in human participants who undergo these diet regimens when compared to calorie-restricted diets.</p> <p>Drawing <a href="https://pubmed.ncbi.nlm.nih.gov/35834774/">definitive conclusions</a> in humans may be more <a href="https://pubmed.ncbi.nlm.nih.gov/32480126/">difficult</a> because of the small sample sizes and individual differences in metabolism, variations in study design (such as the use of different protocols with varying times and duration of food restriction), and participants not complying with their instructions.</p> <h2>Health benefits could be due to eating fewer calories</h2> <p>Most studies describing the health benefits of <a href="https://pubmed.ncbi.nlm.nih.gov/33466692/#:%7E:text=and%20Future%20Perspectives-,Time%2DRestricted%20Eating%20and%20Metabolic%20Syndrome%3A%20Current%20Status%20and%20Future,doi%3A%2010.3390%2Fnu13010221.">time restricted eating</a> or <a href="https://pubmed.ncbi.nlm.nih.gov/27569118/">intermittent fasting</a> also found these diets were accompanied by calorie restriction: reducing the time of food access implicitly leads people to eat less.</p> <p>Studies that controlled calorie intake did not detect any more benefits of intermittent fasting than <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2623528">calorie restriction</a> alone.</p> <p>The weight loss and health benefits observed with intermittent fasting is likely attributed due to the resultant reduction in <a href="https://pubmed.ncbi.nlm.nih.gov/34135111/">calorie intake</a>. <a href="https://pubmed.ncbi.nlm.nih.gov/32986097/">Similar findings</a> have been reported for time-restricted eating.</p> <h2>Benefit of following our body clock</h2> <p>Nevertheless, time-restricted eating offers additional health benefits in humans, such as improved glucose metabolism and blood pressure, even without differences in calorie intake, in particular when restricted to the <a href="https://pubmed.ncbi.nlm.nih.gov/29754952/">earlier part of the day</a> (that is, when having a six-hour eating window with dinner before 3pm).</p> <p>Restricting food intake to the daytime for shift-workers <a href="https://pubmed.ncbi.nlm.nih.gov/28635334/">can alleviate</a> metabolic differences caused by shift-work, whereas this effect is not observed when food intake is restricted to <a href="https://www.science.org/doi/10.1126/sciadv.abg9910">nighttime</a>.</p> <p>One idea is that consuming food early, in alignment with our circadian rhythm, helps to <a href="https://pubmed.ncbi.nlm.nih.gov/28578930/">synchronise our circadian clock</a>. This restores the rhythm of our autonomous nervous system, which regulates essential functions such as breathing and heart rate, to keep our physiology “tuned”, as it was shown <a href="https://www.pnas.org/doi/10.1073/pnas.2015873118">in mice</a>.</p> <p>While there’s much still to learn from research in this field, the evidence suggests that to maintain a healthy weight and overall wellbeing, aim for regular, nutritious meals during the day, while avoiding late-night eating and frequent snacking.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/203762/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/frederic-gachon-1379094">Frederic Gachon</a>, Associate Professor, Physiology of Circadian Rhythms, Institute for Molecular Bioscience, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/meltem-weger-1408599">Meltem Weger</a>, Postdoctoral Research Fellow, Institute for Molecular Bioscience, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a></em></p> <p><em>Image credits: Getty Images</em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/does-it-matter-what-time-of-day-i-eat-and-can-intermittent-fasting-improve-my-health-heres-what-the-science-says-203762">original article</a>.</em></p>

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Does a woman’s menstrual cycle affect her athletic performance? Here’s what the science says

<p><em><a href="https://theconversation.com/profiles/sara-chica-latorre-1443479">Sara Chica-Latorre</a>, <a href="https://theconversation.com/institutions/university-of-canberra-865">University of Canberra</a> and <a href="https://theconversation.com/profiles/michael-pengelly-1443674">Michael Pengelly</a>, <a href="https://theconversation.com/institutions/university-of-canberra-865">University of Canberra</a></em></p> <p>During the Women’s FIFA World Cup, it has been wonderful to see the spotlight turn to female athletes.</p> <p>There’s always been <a href="https://pubmed.ncbi.nlm.nih.gov/24766579/">more research on male athletes</a> compared to female athletes, but the gap is narrowing.</p> <p>One thing we still don’t know enough about is the effect of the menstrual cycle on athletic performance.</p> <h2>What does the menstrual cycle do to a woman’s body?</h2> <p>The menstrual cycle is a complex cascade of events typically lasting 28 days. The primary female sex hormones oestrogen and progesterone rise and fall as the body cycles through four phases, beginning at menstruation, maturation and releasing of an egg (ovulation), preparation for pregnancy, and restarting the cycle if the egg is not fertilised.</p> <p>Fluctuations in female sex hormones have been associated with changes in inflammation, metabolism, muscle activation and body composition, which <a href="https://pubmed.ncbi.nlm.nih.gov/33572406/">can influence athletic performance</a>.</p> <p>For instance, <a href="https://pubmed.ncbi.nlm.nih.gov/22306563/">inflammation decreases</a> when the body is preparing to ovulate, reaching its lowest point around ovulation. It then increases following ovulation and peaks during menstruation.</p> <p>This peak coincides with lower perceived performance among many female athletes.</p> <p>The menstrual cycle can also give rise to symptoms including pain, cramps, weakness, and poor sleep and focus, <a href="https://pubmed.ncbi.nlm.nih.gov/35911030/">challenging performance</a> during training and competition.</p> <p>For example, <a href="https://doi.org/10.1080/24733938.2021.2020330">research</a> conducted in elite female soccer players found over 87% of players perceived reduced power and increased fatigue during menstruation, while over 66% perceived their reaction time and recovery to be affected.</p> <p>Considering the approximate maximum career length of soccer players (21 years) and a woman’s fertile life, that adds up to about 250 times throughout a woman’s soccer career that performance may be compromised.</p> <p>Trends observed among female soccer players closely mirror the experiences of other female athletes, with over <a href="https://pubmed.ncbi.nlm.nih.gov/37389782/#:%7E:text=Results%3A%20Sixty%20studies%20involving%206380,the%20most%20prevalent%20MC%20disorder">74% reporting</a> negative effects mainly during the first days of menstruation.</p> <p>For some, this may lead to reduced training participation, potentially compromising skill development, fitness levels, and even their chances of being selected for competition.</p> <p>But the menstrual cycle is complex, and its effects can vary between athletes and sports. Consequently there is disagreement regarding whether the menstrual cycle universally affects athletic performance, with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10076834/#:%7E:text=Findings%20suggest%20that%20strength%2Drelated,cause%20variations%20in%20strength%20performance">some research</a> <a href="https://pubmed.ncbi.nlm.nih.gov/32661839/">indicating</a> no influence of the menstrual cycle on certain performance measures. But these studies are few and had various logistical limitations, including a small number of participants.</p> <p>Also important to note is that most studies to-date have excluded women using hormonal contraceptives, which is about <a href="https://pubmed.ncbi.nlm.nih.gov/29283683/">50% of female athletes</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/35475746/#:%7E:text=Conclusion%3A%20Most%20WSL%20players%20do,minimise%20discomfort%20and%20maximise%20performance.">28% of female soccer players</a>. The use of hormonal contraceptives suppresses natural hormonal fluctuations and replaces them with external synthetic versions of female sex hormones, affecting the athlete differently.</p> <p>Clearly the extent and severity to which the menstrual cycle impacts athletic performance is highly variable and complex, with more research needed. So for now it’s sensible to consider the effects of the menstrual cycle on an individual basis.</p> <h2>How to support athletic performance at all cycle stages</h2> <p>It’s essential for players to familiarise themselves with their own cycles to understand how they’re affected throughout, as well as communicate any menstrual cycle-related issues to support staff (physicians and coaches). This awareness can guide adjustments in training and nutrition when required.</p> <p>For example, oestrogen has an important influence on iron levels in females, such as chronic oestrogen deficiency is <a href="https://pubmed.ncbi.nlm.nih.gov/23041085/">linked to iron deficiency</a>. Iron status can also be compromised by blood loss during menstruation, depending on the heaviness and duration of bleeding.</p> <p>Iron is essential for human function, facilitating energy production and the transportation of oxygen around the body. In soccer, about <a href="https://pubmed.ncbi.nlm.nih.gov/16521852/#:%7E:text=Of%20the%20investigated%20female%20soccer,at%20the%20top%20international%20level">60% of elite female players</a> present as iron deficient, compared to <a href="https://pubmed.ncbi.nlm.nih.gov/18384395/">less than 12% of their male counterparts</a>. For an iron deficient midfielder, this might translate into covering less distance at lower speeds.</p> <p>It’s therefore important female athletes have their iron levels regularly checked by qualified practitioners. Addressing deficiencies through diet, supplementation, or iron transfusions, will ensure athletic performance during training and competition is not compromised.</p> <p>Individual athletes’ training loads can also be strategically managed to accommodate severe menstrual symptoms.</p> <p>Football clubs around the world have been <a href="https://www.tandfonline.com/doi/full/10.1080/24733938.2020.1828615">experimenting with this strategy</a> since it gained popularity during the 2019 Women’s FIFA World Cup. But how does it look in practice?</p> <p>For team sport athletes, such as soccer players, this can be a demanding logistical task. It’s not easy to track the menstrual cycles of more than 25 players concurrently, and hold training sessions at convenient times for all of them. The complexities are heightened when training and game days cannot be avoided.</p> <p>But performance coaches must consider athletes’ needs and ensure they’re prepared for competition, while minimising the risk of injury and menstrual discomfort. Coaches should also ensure athletes maintain adequate nutrition for both competition and to support their menstrual cycle.</p> <p>For an athlete who reports severe menstrual symptoms during the first days of menstruation (such as increased pain and weakness), this might translate into reduced training intensity, additional recovery days, and an anti-inflammatory diet that also supports the restoration of iron levels (increased intake of nuts, seeds, berries, lean red meats, and fibre and Omega-3 rich foods).</p> <p>And it’s important to keep in mind some athletes might experience menstrual cycle issues in phases other than menstruation. So, training and nutrition should be flexible and individualised across the cycle.</p> <p>Using this approach, athletes can mitigate the influence of the menstrual cycle on their performance, giving them the best opportunity to achieve their athletic potential and success during competition.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/206700/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/sara-chica-latorre-1443479">Sara Chica-Latorre</a>, Phd Candidate and Research Assistant, Research Institute for Sport and Exercise, <a href="https://theconversation.com/institutions/university-of-canberra-865">University of Canberra</a> and <a href="https://theconversation.com/profiles/michael-pengelly-1443674">Michael Pengelly</a>, PhD Candidate, Research Institute for Sport and Exercise, <a href="https://theconversation.com/institutions/university-of-canberra-865">University of Canberra</a></em></p> <p><em>Image credits: Getty Images </em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/does-a-womans-menstrual-cycle-affect-her-athletic-performance-heres-what-the-science-says-206700">original article</a>.</em></p>

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Long COVID could be caused by the virus lingering in the body. Here’s what the science says

<p><a href="https://theconversation.com/profiles/stephen-kent-1283387">Stephen Kent</a>, <em><a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a></em> and <a href="https://theconversation.com/profiles/chansavath-phetsouphanh-1436741">Chansavath Phetsouphanh</a>, <em><a href="https://theconversation.com/institutions/unsw-sydney-1414">UNSW Sydney</a></em></p> <p>While most people survive and recover from COVID, for some people symptoms can <a href="https://www.nature.com/articles/s41586-021-03553-9">persist for months</a> or years. When symptoms last longer than 12 weeks, the condition is known as <a href="https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html">long COVID</a>.</p> <p>Long COVID encompasses up to <a href="https://www.nature.com/articles/s41579-022-00846-2?utm_source=substack&amp;utm_medium=email">200 different symptoms</a>. To determine evidence-based treatments for these symptoms, we need to understand the causes. One factor that may be associated with long COVID is that the virus hasn’t fully cleared from the body after the initial infection.</p> <p>We know from other viruses that viral fragments can remain in different tissues for months or even years. This could be the case with SARS-CoV-2, the virus that causes COVID. Here’s what the science says so far.</p> <h2>Other viruses lurk in the body</h2> <p>Herpesviruses (such as Epstein-Barr virus, the cause of glandular fever), as well as HIV (human immunodeficiency virus) can exist in a “latency state” for life. This means the virus conceals itself within cells and remains dormant.</p> <p>HIV, in particular, can remain dormant in infected cells throughout the body. Even though it’s inactive, it can still promote immune activation and inflammation.</p> <p>Other viruses such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7728251/">Zika</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7492426/">measles</a> and <a href="https://bmjopen.bmj.com/content/6/1/e008859">Ebola</a> have been found in tissues of infected people months or years after initial infection. This viral persistence can <a href="https://www.ahajournals.org/doi/10.1161/circulationaha.105.548156">cause chronic illness</a>.</p> <p>Several studies have shown COVID can also reactivate the Epstein-Barr virus, which has remained in the body in a latent state. Research shows this has been <a href="https://www.jci.org/articles/view/163669">linked to</a> fatigue and problems with thinking and reasoning in <a href="https://www.mdpi.com/2076-0817/10/6/763">people with long COVID</a>.</p> <figure class="align-center "><img src="https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=400&amp;fit=crop&amp;dpr=1 600w, https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=400&amp;fit=crop&amp;dpr=2 1200w, https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=400&amp;fit=crop&amp;dpr=3 1800w, https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=503&amp;fit=crop&amp;dpr=1 754w, https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=503&amp;fit=crop&amp;dpr=2 1508w, https://images.theconversation.com/files/530287/original/file-20230606-15-u0ykc8.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=503&amp;fit=crop&amp;dpr=3 2262w" alt="Man looks at laptop, confused" /><figcaption><span class="caption">Latent viruses can cause fatigue and problems with thinking and reasoning.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/4-EeTnaC1S4">Wes Hicks/Unsplash</a></span></figcaption></figure> <h2>How do we know COVID stays in the body?</h2> <p>Several studies have identified the genetic sequences of SARS-CoV-2 (RNA) as well as SARS-CoV-2 proteins in tissues and stool (poo) samples months following infection.</p> <p>These studies include multiple autopsy reports that <a href="https://www.nature.com/articles/s41586-022-05542-y">found viral RNA and protein in a variety of tissues</a> from people who died up to seven months after infection. SARS-CoV-2 RNA was detected in at least half the samples of heart, lymph glands, eye, nerve, brain and lung tissue tested.</p> <p>In people who survived, <a href="https://www.nature.com/articles/s41586-021-03207-w">viral RNA was found</a> four months after infection within intestinal tissues obtained through colonoscopy, when a thin tube is used to take tissue from the large intestine. These patients had asymptomatic COVID and were PCR-negative from swabs of the nose and throat at four months.</p> <p>A 2022 study found SARS-CoV-2 in the stool of about half of the participants in the first week after infection. At four months, there was no virus present in the respiratory tract but <a href="https://doi.org/10.1016/j.medj.2022.04.001">12.7% of stool samples were RNA positive</a>. A further 3.8% of faecal samples remained positive for RNA at seven months.</p> <p><a href="https://doi.org/10.1016/S2213-2600(21)00240-X">Initial studies</a> did not always suggest a strong relationship between the long-term detection of SARS-CoV-2 and long COVID symptoms.</p> <p>But more recently, the presence of SARS-CoV-2 RNA (or protein translated from RNA) in the <a href="https://academic.oup.com/cid/article/76/3/e487/6686531">blood</a> and gut tissue was found to <a href="https://doi.org/10.1053/j.gastro.2022.04.037">increase the likelihood</a> of developing long COVID symptoms.</p> <figure class="align-center "><img src="https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=335&amp;fit=crop&amp;dpr=1 600w, https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=335&amp;fit=crop&amp;dpr=2 1200w, https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=335&amp;fit=crop&amp;dpr=3 1800w, https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=421&amp;fit=crop&amp;dpr=1 754w, https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=421&amp;fit=crop&amp;dpr=2 1508w, https://images.theconversation.com/files/530289/original/file-20230606-27-p7vgd8.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=421&amp;fit=crop&amp;dpr=3 2262w" alt="Person gets a blood test" /><figcaption><span class="caption">The presence of SARS-CoV-2 in the blood increases the likelihood of developing long COVID symptoms.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/ufwC2cmbaaI">Nguyễn Hiệp/Unsplash</a></span></figcaption></figure> <h2>How might the delay in clearing the virus impact people with long COVID?</h2> <p>Delayed clearance of SARS-CoV-2 particles in different parts of the body could drive illness through several potential processes:</p> <p><strong>1) Inflammation</strong>. The continued immune stimulation by viral proteins causes inflammation, makes our immune system tired, and alters how our immune cells work as time goes on.</p> <p><a href="https://www.nature.com/articles/s41590-021-01113-x">We have previously shown</a> immune dysfunction and inflammation persist up to eight months in people with long COVID that initially had mild to moderate disease.</p> <p><strong>2) Activation of other dormant viruses</strong>. The continued immune response to persistent SARS-CoV-2 can cause reactivation of latent viruses.</p> <p>Antibodies reactive to Epstein-Barr virus are elevated in people with long COVID suggesting Epstein-Barr virus <a href="https://doi.org/10.1101/2022.08.09.22278592">reactivation</a>, likely through activating the immune system.</p> <p>Other latent viruses, such as human endogenous retroviruses (HERVs; ancient viruses that have become a part of our DNA, like a genetic fossil) have recently been shown to become reactivated after infection. HERV proteins <a href="https://www.sciencedirect.com/science/article/pii/S2589004223006818">were detected</a> in blood cells and tissues of COVID patients.</p> <p>These proteins could potentially drive inflammatory processes in long COVID.</p> <figure class="align-center "><img src="https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=400&amp;fit=crop&amp;dpr=1 600w, https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=400&amp;fit=crop&amp;dpr=2 1200w, https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=400&amp;fit=crop&amp;dpr=3 1800w, https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=503&amp;fit=crop&amp;dpr=1 754w, https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=503&amp;fit=crop&amp;dpr=2 1508w, https://images.theconversation.com/files/530290/original/file-20230606-27-6s4g00.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=503&amp;fit=crop&amp;dpr=3 2262w" alt="3D illustration of the Epstein-Barr virus in green and red" /><figcaption><span class="caption">Reactivation of the Epstein-Barr virus could drive inflammation in long COVID.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/epsteinbarr-virus-ebv-herpes-which-causes-556379407">Shutterstock</a></span></figcaption></figure> <p><strong>3) Antibodies made by combating SARS-CoV-2 could become “self” reactive.</strong> These autoantibodies (antibodies produced by our immune system that mistakenly target and attack our own body’s tissues or organs) might cross-react with host receptors or proteins and <a href="https://www.nature.com/articles/s41577-020-00458-y">drive autoimmune</a> disease.</p> <p>Importantly, recent studies have shown new onset of autoimmune diseases (such as type 1 diabetes, inflammatory bowel disease and psoriasis) are significantly associated with SARS-CoV-2 infection and <a href="https://www.nature.com/articles/s41584-023-00964-y">a link between autoimmunity and long COVID</a> is plausible.</p> <p>This suggests COVID not only has immediate health impacts but could also potentially trigger long-term changes in the immune system.</p> <p>While the studies mentioned above provide initial evidence of persistence of SARS-CoV-2 long after initial infection, more studies are needed to show a convincing link between lingering virus and long COVID. This should include examination of viral RNA and protein in both blood and tissues in people with long COVID independent of disease severity. And it must involve well-developed cohort studies that track large groups of people internationally.</p> <p><a href="https://clinicaltrials.gov/ct2/show/NCT05668091">Several</a> <a href="https://clinicaltrials.gov/ct2/show/NCT05576662">trials are underway</a> to assess whether treating long COVID with antivirals such as Paxlovid may reduce viral antigens and improve symptoms, although this remains experimental.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/205025/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /></p> <p><a href="https://theconversation.com/profiles/stephen-kent-1283387">Stephen Kent</a>, Professor and Laboratory Head, <em><a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a></em> and <a href="https://theconversation.com/profiles/chansavath-phetsouphanh-1436741">Chansavath Phetsouphanh</a>, Senior Research Associate, Kirby Institute, <em><a href="https://theconversation.com/institutions/unsw-sydney-1414">UNSW Sydney</a></em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/long-covid-could-be-caused-by-the-virus-lingering-in-the-body-heres-what-the-science-says-205025">original article</a>.</em></p> <p><em>Images: Getty</em></p>

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ChatGPT and other generative AI could foster science denial and misunderstanding – here’s how you can be on alert

<p><em><a href="https://theconversation.com/profiles/gale-sinatra-1234776">Gale Sinatra</a>, <a href="https://theconversation.com/institutions/university-of-southern-california-1265">University of Southern California</a> and <a href="https://theconversation.com/profiles/barbara-k-hofer-1231530">Barbara K. Hofer</a>, <a href="https://theconversation.com/institutions/middlebury-1247">Middlebury</a></em></p> <p>Until very recently, if you wanted to know more about a controversial scientific topic – stem cell research, the safety of nuclear energy, climate change – you probably did a Google search. Presented with multiple sources, you chose what to read, selecting which sites or authorities to trust.</p> <p>Now you have another option: You can pose your question to ChatGPT or another generative artificial intelligence platform and quickly receive a succinct response in paragraph form.</p> <p>ChatGPT does not search the internet the way Google does. Instead, it generates responses to queries by <a href="https://www.washingtonpost.com/technology/2023/05/07/ai-beginners-guide/">predicting likely word combinations</a> from a massive amalgam of available online information.</p> <p>Although it has the potential for <a href="https://hbr.org/podcast/2023/05/how-generative-ai-changes-productivity">enhancing productivity</a>, generative AI has been shown to have some major faults. It can <a href="https://www.scientificamerican.com/article/ai-platforms-like-chatgpt-are-easy-to-use-but-also-potentially-dangerous/">produce misinformation</a>. It can create “<a href="https://www.nytimes.com/2023/05/01/business/ai-chatbots-hallucination.html">hallucinations</a>” – a benign term for making things up. And it doesn’t always accurately solve reasoning problems. For example, when asked if both a car and a tank can fit through a doorway, it <a href="https://www.nytimes.com/2023/03/14/technology/openai-new-gpt4.html">failed to consider both width and height</a>. Nevertheless, it is already being used to <a href="https://www.washingtonpost.com/media/2023/01/17/cnet-ai-articles-journalism-corrections/">produce articles</a> and <a href="https://www.nytimes.com/2023/05/19/technology/ai-generated-content-discovered-on-news-sites-content-farms-and-product-reviews.html">website content</a> you may have encountered, or <a href="https://www.nytimes.com/2023/04/21/opinion/chatgpt-journalism.html">as a tool</a> in the writing process. Yet you are unlikely to know if what you’re reading was created by AI.</p> <p>As the authors of “<a href="https://global.oup.com/academic/product/science-denial-9780197683330">Science Denial: Why It Happens and What to Do About It</a>,” we are concerned about how generative AI may blur the boundaries between truth and fiction for those seeking authoritative scientific information.</p> <p>Every media consumer needs to be more vigilant than ever in verifying scientific accuracy in what they read. Here’s how you can stay on your toes in this new information landscape.</p> <h2>How generative AI could promote science denial</h2> <p><strong>Erosion of epistemic trust</strong>. All consumers of science information depend on judgments of scientific and medical experts. <a href="https://doi.org/10.1080/02691728.2014.971907">Epistemic trust</a> is the process of trusting knowledge you get from others. It is fundamental to the understanding and use of scientific information. Whether someone is seeking information about a health concern or trying to understand solutions to climate change, they often have limited scientific understanding and little access to firsthand evidence. With a rapidly growing body of information online, people must make frequent decisions about what and whom to trust. With the increased use of generative AI and the potential for manipulation, we believe trust is likely to erode further than <a href="https://www.pewresearch.org/science/2022/02/15/americans-trust-in-scientists-other-groups-declines/">it already has</a>.</p> <p><strong>Misleading or just plain wrong</strong>. If there are errors or biases in the data on which AI platforms are trained, that <a href="https://theconversation.com/ai-information-retrieval-a-search-engine-researcher-explains-the-promise-and-peril-of-letting-chatgpt-and-its-cousins-search-the-web-for-you-200875">can be reflected in the results</a>. In our own searches, when we have asked ChatGPT to regenerate multiple answers to the same question, we have gotten conflicting answers. Asked why, it responded, “Sometimes I make mistakes.” Perhaps the trickiest issue with AI-generated content is knowing when it is wrong.</p> <p><strong>Disinformation spread intentionally</strong>. AI can be used to generate compelling disinformation as text as well as deepfake images and videos. When we asked ChatGPT to “<a href="https://www.scientificamerican.com/article/ai-platforms-like-chatgpt-are-easy-to-use-but-also-potentially-dangerous/">write about vaccines in the style of disinformation</a>,” it produced a nonexistent citation with fake data. Geoffrey Hinton, former head of AI development at Google, quit to be free to sound the alarm, saying, “It is hard to see how you can prevent the bad actors from <a href="https://www.nytimes.com/2023/05/01/technology/ai-google-chatbot-engineer-quits-hinton.html">using it for bad things</a>.” The potential to create and spread deliberately incorrect information about science already existed, but it is now dangerously easy.</p> <p><strong>Fabricated sources</strong>. ChatGPT provides responses with no sources at all, or if asked for sources, may present <a href="https://economistwritingeveryday.com/2023/01/21/chatgpt-cites-economics-papers-that-do-not-exist/">ones it made up</a>. We both asked ChatGPT to generate a list of our own publications. We each identified a few correct sources. More were hallucinations, yet seemingly reputable and mostly plausible, with actual previous co-authors, in similar sounding journals. This inventiveness is a big problem if a list of a scholar’s publications conveys authority to a reader who doesn’t take time to verify them.</p> <p><strong>Dated knowledge</strong>. ChatGPT doesn’t know what happened in the world after its training concluded. A query on what percentage of the world has had COVID-19 returned an answer prefaced by “as of my knowledge cutoff date of September 2021.” Given how rapidly knowledge advances in some areas, this limitation could mean readers get erroneous outdated information. If you’re seeking recent research on a personal health issue, for instance, beware.</p> <p><strong>Rapid advancement and poor transparency</strong>. AI systems continue to become <a href="https://www.nytimes.com/2023/05/01/technology/ai-google-chatbot-engineer-quits-hinton.html">more powerful and learn faster</a>, and they may learn more science misinformation along the way. Google recently announced <a href="https://www.nytimes.com/2023/05/10/technology/google-ai-products.html">25 new embedded uses of AI in its services</a>. At this point, <a href="https://theconversation.com/regulating-ai-3-experts-explain-why-its-difficult-to-do-and-important-to-get-right-198868">insufficient guardrails are in place</a> to assure that generative AI will become a more accurate purveyor of scientific information over time.</p> <h2>What can you do?</h2> <p>If you use ChatGPT or other AI platforms, recognize that they might not be completely accurate. The burden falls to the user to discern accuracy.</p> <p><strong>Increase your vigilance</strong>. <a href="https://www.niemanlab.org/2022/12/ai-will-start-fact-checking-we-may-not-like-the-results/">AI fact-checking apps may be available soon</a>, but for now, users must serve as their own fact-checkers. <a href="https://www.nsta.org/science-teacher/science-teacher-januaryfebruary-2023/plausible">There are steps we recommend</a>. The first is: Be vigilant. People often reflexively share information found from searches on social media with little or no vetting. Know when to become more deliberately thoughtful and when it’s worth identifying and evaluating sources of information. If you’re trying to decide how to manage a serious illness or to understand the best steps for addressing climate change, take time to vet the sources.</p> <p><strong>Improve your fact-checking</strong>. A second step is <a href="https://doi.org/10.1037/edu0000740">lateral reading</a>, a process professional fact-checkers use. Open a new window and search for <a href="https://www.nsta.org/science-teacher/science-teacher-mayjune-2023/marginalizing-misinformation">information about the sources</a>, if provided. Is the source credible? Does the author have relevant expertise? And what is the consensus of experts? If no sources are provided or you don’t know if they are valid, use a traditional search engine to find and evaluate experts on the topic.</p> <p><strong>Evaluate the evidence</strong>. Next, take a look at the evidence and its connection to the claim. Is there evidence that genetically modified foods are safe? Is there evidence that they are not? What is the scientific consensus? Evaluating the claims will take effort beyond a quick query to ChatGPT.</p> <p><strong>If you begin with AI, don’t stop there</strong>. Exercise caution in using it as the sole authority on any scientific issue. You might see what ChatGPT has to say about genetically modified organisms or vaccine safety, but also follow up with a more diligent search using traditional search engines before you draw conclusions.</p> <p><strong>Assess plausibility</strong>. Judge whether the claim is plausible. <a href="https://doi.org/10.1016/j.learninstruc.2013.03.001">Is it likely to be true</a>? If AI makes an implausible (and inaccurate) statement like “<a href="https://www.usatoday.com/story/news/factcheck/2022/12/23/fact-check-false-claim-covid-19-vaccines-caused-1-1-million-deaths/10929679002/">1 million deaths were caused by vaccines, not COVID-19</a>,” consider if it even makes sense. Make a tentative judgment and then be open to revising your thinking once you have checked the evidence.</p> <p><strong>Promote digital literacy in yourself and others</strong>. Everyone needs to up their game. <a href="https://theconversation.com/how-to-be-a-good-digital-citizen-during-the-election-and-its-aftermath-148974">Improve your own digital literacy</a>, and if you are a parent, teacher, mentor or community leader, promote digital literacy in others. The American Psychological Association provides guidance on <a href="https://www.apa.org/topics/social-media-internet/social-media-literacy-teens">fact-checking online information</a> and recommends teens be <a href="https://www.apa.org/topics/social-media-internet/health-advisory-adolescent-social-media-use">trained in social media skills</a> to minimize risks to health and well-being. <a href="https://newslit.org/">The News Literacy Project</a> provides helpful tools for improving and supporting digital literacy.</p> <p>Arm yourself with the skills you need to navigate the new AI information landscape. Even if you don’t use generative AI, it is likely you have already read articles created by it or developed from it. It can take time and effort to find and evaluate reliable information about science online – but it is worth it.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/204897/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/gale-sinatra-1234776">Gale Sinatra</a>, Professor of Education and Psychology, <a href="https://theconversation.com/institutions/university-of-southern-california-1265">University of Southern California</a> and <a href="https://theconversation.com/profiles/barbara-k-hofer-1231530">Barbara K. Hofer</a>, Professor of Psychology Emerita, <a href="https://theconversation.com/institutions/middlebury-1247">Middlebury</a></em></p> <p><em>Image credits: Getty Images</em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/chatgpt-and-other-generative-ai-could-foster-science-denial-and-misunderstanding-heres-how-you-can-be-on-alert-204897">original article</a>.</em></p>

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Am I too old to build muscle? What science says about sarcopenia and building strength later in life

<p><a href="https://theconversation.com/profiles/david-scott-1258511">David Scott</a>, <em><a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a></em> and <a href="https://theconversation.com/profiles/robin-m-daly-19560">Robin M. Daly</a>, <em><a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a></em></p> <p>Sarcopenia is the progressive and accelerated loss of muscle mass and strength as we age.</p> <p>The term was coined in the 1980s, and the condition has been recognised as a disease for less <a href="https://onlinelibrary.wiley.com/doi/full/10.5694/mja2.50432">than a decade</a>, but the concept is as old as time: use it or lose it.</p> <p>But what if you’re in your 60s, 70s, 80s or 90s? Is it “too late” to build muscle and fight sarcopenia? Here’s what the research says.</p> <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525756/original/file-20230511-19-34yuj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="" /></a><figcaption><span class="caption">Exercise training during weight loss can also prevent bone loss.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure> <h2>Sarcopenia isn’t just unfortunate. It’s dangerous</h2> <p>All of us will start to gradually lose muscle from our mid-30s, but this loss accelerates in later years. For up to 30% of adults aged over 60, the declines are substantial enough to meet the <a href="https://onlinelibrary.wiley.com/doi/10.1002/jcsm.12783">definition for sarcopenia</a>.</p> <p>Sarcopenia increases your risk of falls, fractures, hospitalisation, loss of independence and many other chronic diseases.</p> <p>However, people who are active in early life and maintain this as they age can delay or prevent the <a href="https://onlinelibrary.wiley.com/doi/10.1002/jcsm.13218">onset of sarcopenia</a>.</p> <p>The good news is it’s never too late to make a start, even if you are already experiencing the debilitating effects of sarcopenia.</p> <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=392&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=392&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=392&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525520/original/file-20230511-29-5201jv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=492&fit=crop&dpr=3 2262w" alt="" /></a><figcaption><span class="caption">It’s never too late to make a start.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure> <h2>What the science says</h2> <p>Resistance training is the most effective way to build and strengthen muscle at all ages. That means things like:</p> <ul> <li> <p>lifting free weights like dumbbells</p> </li> <li> <p>using machine weights, like you find in a gym</p> </li> <li> <p>using resistance bands</p> </li> <li> <p>bodyweight exercises such as push-ups, squats, wall-sits or tricep dips.</p> </li> </ul> <p>It’s OK to start with even very light weights, or do modified, easier versions of bodyweight exercises (for example, you might do a shallow squat rather than a deep one, or a push-up against a wall or windowsill instead of on the floor). Something is always better than nothing.</p> <p>Aim to make the exercise harder over time. Lift progressively heavier weights or do increasingly harder versions of bodyweight or resistance band exercises. This is called progressive resistance training.</p> <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525565/original/file-20230511-27-1sxqpo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="" /></a><figcaption><span class="caption">Aim to make the exercise harder over time.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure> <p><a href="https://link.springer.com/article/10.1007/s40279-020-01331-7?fbclid=IwAR06PPIz8cf2xZExNvrnlueQp0-7SWQwT1x0bUdnZrgTOqcyiAdTrpufTjU">Clinical trials</a> have consistently shown all adults – even very frail people over the age of 75 – can make significant gains in muscle mass and strength by doing progressive resistance training at least twice a week. The improvements can be seen in as little as eight weeks.</p> <p><a href="https://pubmed.ncbi.nlm.nih.gov/2342214/">One seminal study</a> included ten frail, institutionalised 86–96 year olds who did a high-intensity progressive resistance training program.</p> <p>After just eight weeks, the average mid-thigh muscle area had increased by almost 10% (which is equivalent to the amount of muscle typically lost over a decade) and leg strength increased by about 180%.</p> <p>In other words, these older people were almost three times stronger at the end of the short training program than before.</p> <p>It really can be done. British-Swiss man <a href="https://www.youtube.com/watch?v=rGgoCm1hofM">Charles Eugster</a> (1919–2017), for example, took up progressive resistance training in his late 80s after noticing a decline in his muscle mass. He went on to become a <a href="https://www.bodybuilding.com/fun/lessons-from-a-95-year-old-bodybuilder.html">bodybuilder</a>, and in 2012 gave a TEDx <a href="https://www.youtube.com/watch?v=rGgoCm1hofM">talk</a> titled “Why bodybuilding at age 93 is a great idea”.</p> <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6689%2C4466&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6689%2C4466&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525755/original/file-20230511-23-xwcq71.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="" /></a><figcaption><span class="caption">Resistance training is the most effective way to build and strengthen muscle at all ages.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure> <h2>What if my doctor has told me to lose weight?</h2> <p>Many older adults have obesity, which increases the risk of cardiovascular disease and type 2 diabetes.</p> <p>They’re often told to lose weight, but any dieting (or other strategy aimed at weight loss) also usually causes muscle loss.</p> <p>Losing muscle mass in older age could increase the risk for many common chronic conditions. For example, muscle is crucial to keeping blood sugar levels under control, so excessive muscle loss could blunt the benefits of weight loss for people with type 2 diabetes.</p> <p>If you’re losing weight, it’s important to try to minimise muscle mass loss at the same time. How? Progressive resistance training.</p> <p>By combining progressive resistance training with weight loss, one study found the resulting muscle loss is <a href="https://pubmed.ncbi.nlm.nih.gov/29596307/">negligible</a>. (It’s also important that if you are dieting, you are still eating <a href="https://www.clinicalnutritionjournal.com/article/S0261-5614(14)00111-3/fulltext">enough protein</a>, so your body has the ingredients it needs to build new muscle).</p> <p>Exercise training during weight loss can also prevent <a href="https://www.sciencedirect.com/science/article/pii/S2095254621000491">bone loss</a>, which reduces fracture risk in older people.</p> <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&rect=0%2C19%2C4368%2C2877&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&rect=0%2C19%2C4368%2C2877&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/520175/original/file-20230411-26-v63lvh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="" /></a><figcaption><span class="caption">An accredited exercise professional can help design a program that suits you.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure> <h2>Aim for at least twice a week – more if you can</h2> <p>Whether or not you’re trying to lose weight, and regardless of whether you think you have sarcopenia, all older adults can benefit from strengthening their muscles.</p> <p>Even if getting to a gym or clinic is hard, there are plenty of resistance exercises you can do at home or outdoors that will help build strength.</p> <figure class="align-right zoomable"><a href="https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525783/original/file-20230512-35478-3o1th8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1130&fit=crop&dpr=3 2262w" alt="" width="498" height="747" /></a><figcaption></figcaption></figure> <p>Talk to a health professional before starting a moderate to high intensity progressive resistance training program. An accredited exercise professional can help design a program that suits you.</p> <p>Generally, we should aim to do progressive resistance training at least <a href="https://link.springer.com/article/10.1007/s12603-021-1665-8">twice a week</a>.</p> <p>Try to target 8–10 muscle groups, and start out at about 30–40% of your maximum effort before progressing over time to 70–80% of your maximum.</p> <p>As the name suggests, it is key to progressively increase the effort or challenge of your program so you can feel the improvements and achieve your goals.</p> <p>It’s never too late to start training for your fight against sarcopenia and loss of independence in older age. The health benefits will be worth it. As Socrates <a href="https://www.sacred-texts.com/cla/plato/theaetet.htm">said</a> in the 4th Century BC:</p> <blockquote> <p>is not the bodily habit spoiled by rest and idleness, but preserved for a long time by motion and exercise?<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/203562/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> </blockquote> <p><a href="https://theconversation.com/profiles/david-scott-1258511">David Scott</a>, Associate Professor (Research) and NHMRC Emerging Leadership Fellow, <em><a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a></em> and <a href="https://theconversation.com/profiles/robin-m-daly-19560">Robin M. Daly</a>, Professor of Exercise and Ageing, Institute for Physical Activity and Nutrition, Deakin University, <em><a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a></em></p> <p>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/am-i-too-old-to-build-muscle-what-science-says-about-sarcopenia-and-building-strength-later-in-life-203562">original article</a>.</p>

Body

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Deadly Colombian volcano could be about to erupt, warn scientists

<div class="copy"> <p>On March 30, Colombia’s Geological Service raised its alert level on the volcano from yellow to orange. They warn that the volcano could erupt with a strength unseen in the last 10 years within “weeks or days”.</p> <p>President of Colombia Gustavo Petro on April 5 ordered the voluntary evacuation of about 2,500 families living near the volcano. Many locals have been unwilling to leave their belongings and livelihoods behind.</p> <p>Geologists monitoring the volcano have recorded thousands of tremors every day – an unprecedented number.</p> <p>Nevado del Ruiz, one of Colombia’s tallest peaks at 5,321 metres high, is located in a populated farming region. It is only 129 km west of the country’s capital city Bogotá.</p> <p>In 1985, the volcano erupted with tragic consequences. It triggered mudslides that nearly completely buried the town of Armero. More than 23,000 of the town’s 30,000 residents were killed.</p> <p>Despite humanity’s long history of living under the shadow of volcanoes and trying to understand them, geologists, seismologists and vulcanologists remain largely baffled by the lava-spewing behemoths.</p> <p>The last time the threat level of Nevado del Ruiz was raised, for example, was in 2012. For over a month in April of that year, residents were under orange alert. This was increased to red alert for two days in June. But no major eruption occurred.</p> <p>Recently, new methods for assessing the risk of volcanic eruption have been trialled from studying the <a href="https://cosmosmagazine.com/earth/volcano-breath-test-predict-eruptions/" target="_blank" rel="noreferrer noopener">chemical composition of the atmosphere</a> above active volcanoes to <a href="https://cosmosmagazine.com/earth/ai-volcano-eruptions/" target="_blank" rel="noreferrer noopener">utilising artificial intelligence</a> to try and make sense of the pattern of eruptions.</p> <p>University of Miami professor in marine geosciences Falk Amelung believes the threat should not be taken lightly.</p> <p>“This is a high-risk and well-monitored volcano, and right now, all the ingredients for a new eruption are there,” Amelung says in a university <a href="https://www.newswise.com/articles/is-colombia-s-deadly-nevado-del-ruiz-on-the-verge-of-a-major-eruption#!" target="_blank" rel="noreferrer noopener">press release</a> on <em>Newswise</em>. “A significant seismic swarm occurred on March 30, and this [low-magnitude] earthquake sequence strongly suggests that magma is on the move.”</p> <p>Like Mount St Helens in Washington state, US which famously erupted in 1980, killing 57 people, Nevado del Ruiz is a glacier-covered volcano. Amelung says that this places local residents under extra peril.</p> <p>“Even a relatively small eruption would melt the glacier,” Amelung explains. “Volcanic ash combined with the meltwater would form mudflows, known as lahars, that can travel fast and for several miles.”</p> <div class="in-content-area content-third content-right"><a href="https://cosmosmagazine.com/earth/massive-tongan-eruption-claimed-few-lives-due-to-quirk/"> </a></div> <p>Amelung admits it is impossible to say with certainty what will happen.</p> <p>“This increased period of activity could well die down and nothing happens,” he says.</p> <p>Ironically, global warming over the last 38 years since the eruption which saw the inundation of Armero, means the glaciers that cover the volcano’s summit are smaller, lessening lahar hazards.</p> <p>“But it is also bad news in terms of eruption hazards because there is less pressure from the overburden to keep the magma at depth,” Amelung adds.</p> <p><!-- Start of tracking content syndication. Please do not remove this section as it allows us to keep track of republished articles --> <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=246260&amp;title=Deadly+Colombian+volcano+could+be+about+to+erupt%2C+warn+scientists" width="1" height="1" data-spai-target="src" data-spai-orig="" data-spai-exclude="nocdn" /></div> <div id="contributors"> <p><em>This article was originally published on <a href="https://cosmosmagazine.com/earth/colombian-volcano-erupt/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Evrim Yazgin.</em></p> <p><em>Images: Getty</em></p> </div>

Travel Trouble

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Microwaving solar panels makes them easier to recycle

<div> <p><a href="https://cosmosmagazine.com/news/solar-cells-essential-for-brighter-future/" target="_blank" rel="noreferrer noopener">Solar cell</a> manufacturing and recycling should be easier with a surprising new discovery by Macquarie University scientists – that uses a commercial microwave.</p> <p>While they’re being made, the silicon in solar panels goes through a process called “annealing”, which involves heating the materials to temperatures well above 500°C.</p> <p>Annealing is usually done with ovens. But a study <a href="https://doi.org/10.1063/5.0127896" target="_blank" rel="noreferrer noopener">published</a> in Applied Physics Letters shows that microwaves are not only faster and more energy efficient for the job, but make the panels much easier to disassemble, and thus recycle, at the end of life.</p> <p>This is because microwave radiation heats individual substances – like the water in food, or silicon.</p> <p>“It just heats the very thin layer of silicon rather than heating the bulk of the materials around, and it’s really fast,” says lead author Dr Binesh Puthen Veettil, a researcher at Macquarie University’s School of Engineering.</p> <p>This also makes the process easier, because the microwave doesn’t have to be as carefully cleaned.</p> <p>“In most of the high temperature processes, lots of contaminants come out of the walls of the oven. But in this case, the heat is flowing from the silicon outwards, while everything else is at room temperature, it’s kind of a pseudo room temperature process where the contaminants don’t get diffused from outside,” says Veettil.</p> <p>“But the thing we are most excited about is the benefit to recycling.”</p> <p>Currently, solar cell recycling is a very <a href="https://cosmosmagazine.com/earth/sustainability/solar-panel-recycling/" target="_blank" rel="noreferrer noopener">energy intense process</a> which involves crushing up the panels and heating them to temperatures of at least 1000°C, so that all of the expensive elements can be extracted.</p> <p>This method destroys some of the reusable solar cell components: particularly, the toughened glass on the top of the panel.</p> <p>“This glass contains most of the weight of the solar panel,” explains Veettil.</p> <p>That glass is stuck to a layer of plastic, usually ethylene vinyl acetate, which keeps the silicon plate underneath dry. This plastic is too hard to remove, so the whole thing is smashed up, with the glass sold as scrap.</p> <p>But microwaving the silicon specifically softens the plastic, making it easy to peel.</p> <p>“You can just peel off the silicon cell, without destroying the glass, and you can reuse that expensive glass,” says Veettil.</p> <p>“If you can reuse the glass, the recycling will pay for itself.”</p> <p>Plus, it doesn’t need the same high temperatures, or extra chemicals needed to wash and dissolve the plastic.</p> <p>For now, the process is lab-based – and only for solar panels that fit in a commercial microwave.</p> <p>“Initially, when we started the research, we used a laboratory microwave that we purchased from a US company,” says Veettil.</p> <p>“And we after that, we purchased some kitchen microwaves locally, and modified it to suit our purposes.”</p> <p>This modification involved heat-proofing the microwave so that it could handle the annealing temperatures.</p> <p>“It goes from room temperature to 500° Celsius in just two seconds,” says Veettil. (Depending on the size of the sample: bigger things take longer.)</p> <p>But the researchers have a patent pending for the recycling process, and are now investigating how to improve and commercialise it.</p> <p>“We are hoping that with some industry collaboration and funding, we can scale it up,” says Veettil.</p> <p>“Recycling needs to be meet two conditions: it should be environmentally friendly, and second, it should pay for itself.</p> <p>“I’m pretty sure, with the numbers I have in mind, it will it will be profitable and then the market will take care of itself and it organically grow recycling centres. That’s my hope.”</p> </div> <div id="contributors"> <p><em>This article was originally published on <a href="https://cosmosmagazine.com/technology/microwaving-solar-panels-recycling/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Ellen Phiddian.</em></p> <p><em>Images: Getty</em></p> </div>

Technology

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We make thousands of unconscious decisions every day. Here’s how your brain copes with that

<p>Do you remember learning to drive a car? You probably fumbled around for the controls, checked every mirror multiple times, made sure your foot was on the brake pedal, then ever-so-slowly rolled your car forward.</p> <p>Fast forward to now and you’re probably driving places and thinking, “how did I even get here? I don’t remember the drive”. The task of driving, which used to take a lot of mental energy and concentration, has now become subconscious, automatic – habitual.</p> <p>But how – and why – do you go from concentrating on a task to making it automatic?</p> <p><strong>Habits are there to help us cope</strong></p> <p>We live in a vibrant, complex and transient world where we constantly face a barrage of information competing for our attention. For example, our eyes take in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1564115/">over one megabyte of data every second</a>. That’s equivalent to reading 500 pages of information or an entire encyclopedia every minute.</p> <p>Just one whiff of a <a href="https://pubmed.ncbi.nlm.nih.gov/12744840/">familiar smell</a> can trigger a memory from childhood in less than a millisecond, and <a href="https://doi.org/10.1016/j.neubiorev.2009.08.004">our skin</a> contains up to 4 million receptors that provide us with important information about temperature, pressure, texture, and pain.</p> <p>And if that wasn’t enough data to process, <a href="https://www.emerald.com/insight/content/doi/10.1108/REPS-10-2018-011/full/html">we make thousands of decisions</a> every single day. Many of them are unconscious and/or minor, such as putting seasoning on your food, picking a pair of shoes to wear, choosing which street to walk down, and so on.</p> <p>Some people are neurodiverse, and the ways we sense and process the world differ. But generally speaking, because we simply cannot process <a href="https://www.sciencedirect.com/science/article/abs/pii/S1364661305001178">all the incoming data</a>, our brains create habits – automations of the behaviours and actions we often repeat.</p> <p><strong>Two brain systems</strong></p> <p>There are two forces that govern our behaviour: intention and habit. In simple terms, our brain has <a href="https://www.tandfonline.com/doi/full/10.1080/17437199.2016.1244647">dual processing systems</a>, sort of like a computer with two processors.</p> <p>Performing a behaviour for the first time requires intention, attention and planning – even if plans are made only moments before the action is performed.</p> <p>This happens in our prefrontal cortex. More than any other part of the brain, the prefrontal cortex is responsible for making deliberate and logical decisions. It’s the key to reasoning, problem-solving, comprehension, impulse control and perseverance. It affects behaviour via <a href="https://www.cambridge.org/core/books/abs/handbook-of-behavior-change/changing-behavior-using-the-reflectiveimpulsive-model/A35DBA6BF0E784F491E936F2BE910FF7">goal-driven decisions</a>.</p> <p>For example, you use your “reflective” system (intention) to make yourself go to bed on time because sleep is important, or to move your body because you’ll feel great afterwards. When you are learning a new skill or acquiring new knowledge, you will draw heavily on the reflective brain system to form new memory connections in the brain. This system requires mental energy and effort. </p> <p><strong>From impulse to habit</strong></p> <p>On the other hand, your “impulsive” (habit) system is in your brain’s <a href="https://www.annualreviews.org/doi/10.1146/annurev.neuro.29.051605.112851">basal ganglia</a>, which plays a key role in the development of emotions, memories, and pattern recognition. It’s impetuous, spontaneous, and pleasure seeking.</p> <p>For example, your impulsive system might influence you to pick up greasy takeaway on the way home from a hard day at work, even though there’s a home-cooked meal waiting for you. Or it might prompt you to spontaneously buy a new, expensive television. This system requires no energy or cognitive effort as it operates reflexively, subconsciously and automatically.</p> <p>When we repeat a behaviour in a consistent context, our brain recognises the patterns and moves the control of that behaviour from intention to habit. A habit occurs when your impulse towards doing something is automatically initiated because you encounter a setting in which you’ve done the same thing <a href="https://bmcpsychology.biomedcentral.com/articles/10.1186/s40359-015-0065-4">in the past</a>. For example, getting your favourite takeaway because you walk past the food joint on the way home from work every night – and it’s delicious every time, giving you a pleasurable reward.</p> <p><strong>Shortcuts of the mind</strong></p> <p>Because habits sit in the impulsive part of our brain, they <a href="https://doi.org/10.1016/j.biopsych.2019.03.978">don’t require much cognitive input or mental energy</a> to be performed.</p> <p>In other words, habits are the mind’s shortcuts, allowing us to successfully engage in our daily life while reserving our reasoning and executive functioning capacities for other thoughts and actions.</p> <p>Your brain remembers how to drive a car because it’s something you’ve done many times before. Forming habits is, therefore, a natural process that contributes to <a href="https://psycnet.apa.org/doiLanding?doi=10.1037%2F0033-2909.124.1.54">energy preservation</a>.</p> <p>That way, your brain doesn’t have to consciously think about your every move and is free to consider other things – like what to make for dinner, or where to go on your next holiday.</p> <p><em>Image credit: Shutterstock</em></p> <p><em>This article originally appeared on <a href="https://theconversation.com/we-make-thousands-of-unconscious-decisions-every-day-heres-how-your-brain-copes-with-that-201379" target="_blank" rel="noopener">The Conversation</a>. </em></p>

Mind

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Historic Swedish sailing ship slow to give up its secrets

<div> <p>The Swedish ship Vasa was supposed to be a beacon of military might when it launched in 1628, but it sank after sailing just over a kilometre, killing roughly 30 people  in the process.</p> <p>Since its recovery in 1961, the ship, its contents and the people who perished with it have become a valuable insight into 17th-century Swedish life.</p> <p>Now, an international team of researchers has looked closer at one of the skeletons, referred to as G, and have confirmed that it’s female.</p> <p>“Through osteological analysis it has been possible to discover a great deal about these people, such as their age, height and medical history. Osteologists recently suspected that G could be female, on the basis of the pelvis. DNA analysis can reveal even more,” says Dr Fred Hocker, director of research at the Vasa Museum, Sweden.</p> <p>“It is very difficult to extract DNA from bone which has been on the bottom of the sea for 333 years, but not impossible”, says Professor Marie Allen, a forensic geneticist at Uppsala University in Sweden.</p> <p>“Already some years ago we had indications that skeleton G was not a man but a woman. Simply put, we found no Y-chromosomes in G’s genetic material. But we could not be certain and wanted to confirm the result.”</p> <p>They were able to do that with a technique developed by the US Department of Defense’s Armed Forces Medical Examiner System’s Armed Forces DNA Identification Laboratory (AFMES-AFDIL).</p> <p>“We took new samples from bones for which we had specific questions. AFMES-AFDIL has now analysed the samples, and we have been able to confirm that G was a woman, thanks to the new test,” says Allen.</p> <p>Allen, along with AFMES-AFDIL collaborator Dr Kimberly Andreaggi, is now investigating the DNA for more detail about G.</p> <p>“Today we can extract much more information from historic DNA than we could earlier and methods are being continuously refined. We can say if a person was predisposed to certain illnesses, or even very small details, such as if they had freckles and wet or dry ear wax,” says Allen.</p> <p>The Vasa Museum, meanwhile, is collecting information for a book about the people who died on the ship.</p> <p>“We want to come as close to these people as we can. We have known that there were women on board Vasa when it sank, and now we have received confirmation that they are among the remains,” says museum historian Dr Anna Maria Forssberg.</p> <p>“I am currently researching the wives of seamen, so for me this is especially exciting, since they are often forgotten even though they played an important role for the navy.”</p> </div> <div id="contributors"> <p><em>This article was originally published on <a href="https://cosmosmagazine.com/history/vasa-shipwreck-female/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Ellen Phiddian. </em></p> <p><em>Images: Getty</em></p> </div>

Technology

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We were told we’d be riding in self-driving cars by now. What happened to the promised revolution?

<p>According to <a href="https://electrek.co/2015/12/21/tesla-ceo-elon-musk-drops-prediction-full-autonomous-driving-from-3-years-to-2/">predictions</a> <a href="https://www.vanityfair.com/news/2016/09/lyfts-president-says-car-ownership-will-all-but-end-by-2025">made</a> nearly a decade ago, we should be riding around in self-driving vehicles today. It’s now clear the autonomous vehicle revolution was overhyped.</p> <p>Proponents woefully underestimated the technological challenges. It turns out developing a truly driverless vehicle is hard.</p> <p>The other factor driving the hype was the amount of money being invested in autonomous vehicle startups. By 2021, it was estimated more than <a href="https://www.washingtonpost.com/outlook/2022/02/04/self-driving-cars-why/">US$100 billion</a> in venture capital had gone into developing the technology.</p> <p>While advances are being made, it is important to understand there are multiple levels of autonomy. Only one is truly driverless. As established by <a href="https://www.sae.org/blog/sae-j3016-update">SAE International</a>, the levels are:</p> <ul> <li> <p>level 0 — the driver has to undertake all driving tasks</p> </li> <li> <p>level 1, hands on/shared control — vehicle has basic driver-assist features such as cruise control and lane-keeping</p> </li> <li> <p>level 2, hands off – vehicle has advanced driver-assist features such as emergency braking, adaptive cruise control, auto park assist and traffic-jam assist</p> </li> <li> <p>level 3, eyes off — vehicle drives itself some of the time</p> </li> <li> <p>level 4, mind off — vehicle drives itself most of the time</p> </li> <li> <p>level 5, steering wheel option — vehicle drives itself all the time.</p> </li> </ul> <h2>Why the slow progress?</h2> <p>It’s estimated the technology to deliver safe autonomous vehicles is about <a href="https://www.theguardian.com/technology/2022/mar/27/how-self-driving-cars-got-stuck-in-the-slow-lane">80% developed</a>. The last 20% is increasingly difficult. It will take a lot more time to perfect.</p> <p>Challenges yet to be resolved involve unusual and rare events that can happen along any street or highway. They include weather, wildlife crossing the road, and highway construction.</p> <p>Another set of problems has emerged since <a href="https://www.forbes.com/sites/simonmainwaring/2022/08/22/cruise-ride-hailing-goes-green-and-driverless/?sh=6a7439376843">Cruise</a> and <a href="https://www.theverge.com/2022/11/19/23467784/waymo-provide-fully-driverless-rides-san-francisco-california">Waymo</a> launched their autonomous ride-hailing services in San Francisco. The US National Highway Traffic and Safety Administration <a href="https://techcrunch.com/2022/12/16/cruises-autonomous-driving-tech-comes-under-scrutiny-from-safety-regulators/">opened an investigation</a> in December 2022, only six months after the <a href="https://www.theguardian.com/technology/2022/jun/03/california-driverless-taxi-cars-san-francisco">services were approved</a>. It cited incidents where these vehicles “may have engaged in inappropriately hard braking or became immobilized”.</p> <p>The San Francisco County Transportation Authority <a href="https://www.nytimes.com/2023/02/01/technology/self-driving-taxi-san-francisco.html" target="_blank" rel="noopener">stated</a>, "[I]n the months since the initial approval of autonomous taxi services in June 2022, Cruise AVs have made unplanned and unexpected stops in travel lanes, where they obstruct traffic and transit service and intrude into active emergency response scenes, including fire suppression scenes, creating additional hazardous conditions."</p> <p>In several cases, Cruise technicians had to be called to move the vehicles.</p> <h2>What’s happening now?</h2> <p>Active autonomous vehicle initiatives can be grouped into two categories: ride-hailing services (Cruise, Waymo and Uber) and sales to the public (Tesla).</p> <p>Cruise is a subsidiary of General Motors founded in 2013. As of September 2022, it operated 100 robotaxis in San Francisco and had plans to increase its fleet to 5,000. Critics said this would increase city traffic.</p> <p>Cruise also began to offer services in Chandler (a Phoenix suburb), Arizona, and Austin, Texas, in December 2022.</p> <p>Waymo, formerly the Google Self-Driving Car Project, was founded in January 2009. The company lost <a href="https://www.theverge.com/2022/11/11/23453262/waymo-av-driverless-taxi-phoenix-california-dmv-progress">US$4.8 billion in 2020 and US$5.2 billion in 2021</a>.</p> <p>Waymo One provides autonomous ride-hailing services in <a href="https://www.theverge.com/2023/2/28/23617278/waymo-self-driving-driverless-crashes-av">Phoenix as well as San Francisco</a>. It plans to expand into <a href="https://www.theverge.com/2022/10/19/23410677/waymo-los-angeles-autonomous-robotaxi-service-launch">Los Angeles</a> this year.</p> <p>Uber was a major force in autonomous vehicle development as part of its business plan was to replace human drivers. However, it ran into problems, including a crash in March 2018 when a self-driving Uber killed a woman walking her bicycle across a street in Tempe, Arizona. In 2020, Arizona Uber sold its AV research division to Aurora Innovation.</p> <p>But in October 2022 Uber got back into autonomous vehicles by <a href="https://www.forbes.com/sites/samabuelsamid/2022/10/06/motional-and-uber-announce-10-year-deal-to-deploy-automated-vehicles-in-multiple-us-markets/?sh=44d83a84273e">signing a deal</a> with Motional, a joint venture between Hyundai and Aptiv. Motional will provide autonomous vehicles for Uber’s ride-hailing and delivery services.</p> <p>Lyft, the second-largest ride-sharing company after Uber, operates in the US and Canada. Like Uber, Lyft had a self-driving unit and in 2016, Lyft co-founder John Zimmer <a href="https://www.vanityfair.com/news/2016/09/lyfts-president-says-car-ownership-will-all-but-end-by-2025">predicted</a> that by 2021 the majority of rides on its network would be in such vehicles (and private car ownership would “all but end” by 2025). It didn’t happen. By 2021, Lyft had also <a href="https://techcrunch.com/2021/04/26/lyft-sells-self-driving-unit-to-toyotas-woven-planet-for-550m/">sold its self-driving vehicle unit</a>, to Toyota.</p> <p>In 2022, Zimmer <a href="https://techcrunch.com/2022/10/20/lyft-co-founder-says-autonomous-vehicles-wont-replace-drivers-for-at-least-a-decade/">said</a> the technology would not replace drivers for at least a decade. However, Lyft did partner with Motional in August 2022 to launch <a href="https://www.prnewswire.com/news-releases/lyft-and-motional-deliver-the-first-rides-in-motionals-new-all-electric-ioniq-5-autonomous-vehicle-301606519.html">robotaxis in Las Vegas</a> and <a href="https://www.reuters.com/business/autos-transportation/lyft-motional-launch-robotaxi-service-los-angeles-2022-11-17/">Los Angeles</a>.</p> <p>Telsa is the <a href="https://www.ev-volumes.com/">world leader in sales</a> of battery electric vehicles. It also purports to sell vehicles with full automation. However, by the end of 2022, no level 3, 4 or 5 vehicles were for sale in the United States.</p> <p>What Telsa offers is a full self-driving system as a US$15,000 option. Buyers acknowledge they are buying a beta version and assume all risks. If the system malfunctions, Telsa does not accept any responsibility.</p> <p>In February 2023, the National Highway Traffic Safety Administration <a href="https://amp.theguardian.com/technology/2023/feb/16/tesla-recall-full-self-driving-cars">found</a>, "[Fully self-driving] beta software that allows a vehicle to exceed speed limits or travel through intersections in an unlawful or unpredictable manner increases the risk of a crash."</p> <p>This led to Tesla <a href="https://www.theguardian.com/technology/2023/feb/16/tesla-recall-full-self-driving-cars">recalling 362,000 vehicles</a> to update the software.</p> <p>Another setback for autonomous vehicle sales to the public was the October 2022 announcement that Ford and VW had decided to <a href="https://techcrunch.com/2022/10/26/ford-vw-backed-argo-ai-is-shutting-down/">stop funding autonomous driving technology company Argo AI</a>, resulting in its closure. Both Ford and VW decided to shift their focus from level 4 automation to levels 2 and 3.</p> <h2>So, what can we expect next?</h2> <p>Autonomous vehicle development will continue, but with less hype. It’s being recognised as more an evolutionary process than a revolutionary one. The increasing cost of capital will also make it harder for autonomous vehicle startups to get development funds.</p> <p>The areas that appear to be making the best progress are autonomous ride-hailing and heavy vehicles. Self-driving car sales to the public are <a href="https://www.drive.com.au/news/level-4-self-driving-technology-mercedes-benz/">further down the track</a>.</p> <p><em>This article originally appeared on <a href="https://theconversation.com/we-were-told-wed-be-riding-in-self-driving-cars-by-now-what-happened-to-the-promised-revolution-201088" target="_blank" rel="noopener">The Conversation</a>.</em></p> <p><em>Images: Getty</em></p>

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Lie detection tests have worked the same way for 3,000 years – and they’re still hopelessly inaccurate

<p>Popular culture is fascinated with the ability to detect liars. Lie detector tests are a staple of police dramas, and TV shows such as Poker Face feature “human polygraphs” who detect deception by picking up tell-tale signs in people’s behaviour.</p> <p>Records of attempts to detect lies, whether by technical means or by skilled observers, go back at least 3,000 years. Forensic science lie detection techniques have become <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1541-1338.2005.00166.x">increasingly popular</a> since the invention of the polygraph early in the 20th century, with the latest methods involving advanced brain imaging.</p> <p>Proponents of lie detection technology sometimes <a href="https://www.press.umich.edu/3091709/lying_brain">make grandiose claims</a>, such as a <a href="https://doi.org/10.1007/s11896-022-09566-y">recent paper</a> that said “with the help of forensic science and its new techniques, crimes can be easily solved”.</p> <p>Despite these claims, an infallible lie detection method has yet to be found. In fact, most lie detection methods don’t detect lies at all – instead, they register the physiological or behaviour signs of stress or fear.</p> <h2>From dry rice to red-hot irons</h2> <p>The <a href="https://journals.sagepub.com/doi/10.1177/1529100610390861">earliest recorded lie detection method</a> was used in China, around 1000 BC. It involved suspects placing rice in their mouths then spitting it out: wet rice indicated innocence, while dry rice meant guilty.</p> <p>In India, around 900 BC, <a href="http://scholarlycommons.law.northwestern.edu/cgi/viewcontent.cgi?article=2844&amp;context=jclc">one method</a> used to detect poisoners was observations of shaking. In ancient Greece a rapid pulse rate was taken to indicate deceit.</p> <p>The Middle Ages saw barbaric forms of lie detection used in Europe, such as the red-hot iron method which involved suspected criminals placing their tongue, often multiple times, on a red-hot iron. Here, a burnt tongue indicated guilt.</p> <h2>What the polygraph measures</h2> <p>Historical lie detection methods were based in superstition or religion. However, in the early 20th century a purportedly scientific, objective, lie detection machine was invented: the polygraph.</p> <p>The <a href="https://www.ojp.gov/pdffiles1/nij/grants/228091.pdf">polygraph measures</a> a person’s respiration, heart rate, blood pressure, and skin conductance (sweating) during questioning.</p> <p>Usually a “control question” about a crime is asked, such as “Did you do it?” The person’s response to the control question is then compared to responses to neutral or less provocative questions. Heightened reactions to direct crime questions are taken to indicate guilt on the test.</p> <h2>The overconfidence of law enforcers</h2> <p>Some law enforcement experts claim they don’t even need a polygraph. They can detect lies simply by observing the behaviour of a suspect during questioning.</p> <p>Worldwide research shows that law enforcers are often <a href="https://doi.org/10.5093/apj2022a4">confident they can detect lying</a>. Many assume a suspect’s nonverbal behaviour reveals deceit.</p> <p>A <a href="https://www.emerald.com/insight/content/doi/10.1108/14636641111134314/full/html">2011 study with Queensland police</a> revealed many officers were confident they could detect lying. Most favoured a focus on nonverbal behaviour even over available evidence.</p> <p>However, <a href="https://link.springer.com/chapter/10.1007/978-3-319-96334-1_3">research shows</a> that law enforcers, despite their confidence, are often not very good at detecting lying.</p> <p>Law enforcement officers are not alone in thinking they can spot a liar. <a href="https://journals.sagepub.com/doi/10.1177/0022022105282295">Global studies</a> have found that people around the world believe lying is accompanied by specific nonverbal behaviours such as gaze aversion and nervousness.</p> <h2>What’s really being tested</h2> <p>Many historical and current lie detection methods seem underpinned by the plausible idea that liars will be nervous and display observable physical reactions.</p> <p>These might be shaking (such as in the ancient Indian test for poisoners, and the nonverbal behaviour method used by some investigators), a dry mouth (the rice-chewing test and the hot-iron method), increased pulse rate (the ancient Greek method and the modern polygraph), or overall heightened physiological reactions (the polygraph).</p> <p>However, there are two major problems with using behaviour based on fear or stress to detect lying.</p> <p>The first problem: how does one distinguish fearful innocents from fearful guilty people? It is likely that an innocent person accused of a crime will be fearful or anxious, while a guilty suspect may not be.</p> <p>This is borne out with the polygraph’s <a href="https://nap.nationalacademies.org/read/10420/chapter/10#218">high false-positive rate</a>, meaning innocent people are deemed guilty. Similarly, some police have assumed that <a href="https://cqu-primo.hosted.exlibrisgroup.com/permalink/f/1rb43gr/TN_cdi_informaworld_taylorfrancisbooks_9781843926337">innocent, nervous suspects were guilty</a> based on inaccurate interpretations of behavioural observations.</p> <p>The second major problem with lie detection methods based on nervous behaviour is there is <a href="https://journals.copmadrid.org/apj/art/apj2019a9">no evidence</a> that specific nonverbal behaviours reliably accompany deception.</p> <h2>Miscarriages of justice</h2> <p>Despite what we know about the inaccuracy of polygraph tests, they haven’t gone away.</p> <p>In the US, they are still used in some police interrogations and <a href="https://www.wired.com/story/inside-polygraph-job-screening-black-mirror/">high-security job interviews</a>. In the UK, lie detector tests are used for <a href="https://www.gov.uk/government/publications/domestic-abuse-bill-2020-factsheets/mandatory-polygraph-tests-factsheet">some sex offenders on probation</a>. And in China, the use of polygraphs in law enforcement may <a href="https://www.sciencedirect.com/science/article/abs/pii/S0031938414005964?via%3Dihub">even be increasing</a>.</p> <p>Australia has been less enthusiastic in adopting lie-detection machines. In New South Wales, the use of lie-detector findings was barred from court in 1983, and an attempt to present polygraph evidence to a court in Western Australia in 2003 <a href="https://www.tandfonline.com/doi/abs/10.1375/pplt.2004.11.2.359">also failed</a>.</p> <p>Many historical and current lie detection methods emulate each other and are based on the same assumptions. Often the <a href="https://muse.jhu.edu/book/13865">only difference</a> is the which part of the body or physical reaction they focus on.</p> <p>Using fallible lie detection methods <a href="https://journals.copmadrid.org/apj/art/apj2022a4">contributes to wrongful convictions</a> and miscarriages of justice.</p> <p>Therefore, it is important that criminal-justice practitioners are educated about fallacious lie detection methods, and any new technique grounded in fear or stress-based reactions should be rejected.</p> <p>Despite outward appearances of technological advancement, over many millennia little has changed. Fearful innocents remain vulnerable to wrongful assumptions of guilt, which is good news for the fearless guilty.</p> <p><em>This article originally appeared on <a href="https://theconversation.com/lie-detection-tests-have-worked-the-same-way-for-3-000-years-and-theyre-still-hopelessly-inaccurate-200741" target="_blank" rel="noopener">The Conversation</a>.</em></p> <p><em>Images: Getty</em></p>

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Why does music bring back memories? What the science says

<p>You’re walking down a busy street on your way to work. You pass a busker playing a song you haven’t heard in years. Now suddenly, instead of noticing all the goings on in the city around you, you’re mentally reliving the first time you heard the song. Hearing that piece of music takes you right back to where you were, who you were with and the feelings associated with that memory.</p> <p>This experience – when music brings back memories of events, people and places from our past – is known as a <a href="https://doi.org/10.1371/journal.pone.0251692">music-evoked autobiographical memory</a>. And it’s a <a href="https://doi.org/10.1177/0305735619888803">common experience</a>. </p> <p>It often occurs as an <a href="https://doi.org/10.1177/0963721410370301">involuntary memory</a>. That is, we make no effort to try to recall such memories, they just come to mind spontaneously. </p> <p>Research has recently begun to uncover why music appears to be such a good cue for invoking memories. First, music tends to accompany many distinctive life events, such as proms, graduations, weddings and funerals, so it can play an important role in reconnecting us with these <a href="https://doi.org/10.1017/S1041610215000812">self-defining moments</a>.</p> <p>Music also often captures our attention, due to the way it affects our <a href="https://theconversation.com/the-power-of-our-song-the-musical-glue-that-binds-friends-and-lovers-across-the-ages-73593">minds</a>, <a href="https://theconversation.com/rhythm-on-the-brain-and-why-we-cant-stop-dancing-56354">bodies</a> and <a href="https://theconversation.com/why-sad-songs-say-so-much-to-some-people-but-not-others-65365">emotions</a>. </p> <p>When music draws our attention, this increases the likelihood that it will be encoded in memory together with details of a life event. And this then means it is able to serve as an effective cue for remembering this event years later.</p> <h2>Positive memories</h2> <p>In <a href="https://doi.org/10.1016/j.jarmac.2021.09.002">recent research</a> my colleague and I found that the emotional nature of a piece of music is an important factor in how it serves as a memory cue. </p> <p>We compared music with other emotional memory cues that had been rated by a large group of participants as conveying the same emotional expression as the music excerpts we used. This included comparing music with “emotional sounds”, such as nature and factory noises and “emotional words”, such as “money” and “tornado”.</p> <p>When compared with these emotionally matched cues, the music didn’t elicit any more memories than the words. But what we did find was that music evoked more consistently positive memories than other emotional sounds and words. This was especially the case for negative emotional stimuli. Specifically, sad and angry music evoked more positive memories than sad and angry sounds or words. </p> <p>It seems then that music appears to have the ability to reconnect us with emotionally positive moments from our pasts. This suggests that using <a href="https://theconversation.com/why-researchers-are-turning-to-music-as-a-possible-treatment-for-stroke-brain-injuries-and-even-parkinsons-171701">music therapeutically</a> may be particularly fruitful. </p> <h2>How and when</h2> <p>The familiarity of a piece of music also, perhaps unsurprisingly, plays a role. In <a href="https://doi.org/10.1177/17470218221129793">another recent study</a>, we found that more familiar music evokes more memories and brings memories to mind more spontaneously. </p> <p>So part of the reason music may be a more effective cue for memories than, for instance, our favourite film or favourite book, is that we typically reengage with songs more often over our lifetimes compared to films, books or TV shows.</p> <p>The situations when we listen to music may also play a role. <a href="https://doi.org/10.1017/CBO9780511575921">Previous research</a> shows that involuntary memories are more likely to come back during activities where our mind is free to wander to thoughts about our past. These activities tend to be non-demanding in terms of our attention and include things like commuting, travelling, housework and relaxing. </p> <p>These types of activities align almost perfectly with those recorded in another study where we asked participants to <a href="https://doi.org/10.1177/0305735619888803">keep a diary</a> and note when music evoked a memory, along with what they were doing at the time it happened. We found that daily activities that often go hand in hand with listening to music – such as travelling, doing chores or going for a run – tend to lead to more involuntary memories in the first place.</p> <p>This contrasts with other hobbies, <a href="https://doi.org/10.1525/mp.2021.38.5.435">such as watching TV</a>, which can require our mind to be more focused on the activity at hand and so less likely to wander to scenarios from our past. </p> <p>It seems then that music is not only good at evoking memories but also the times when we are more likely to listen to music are the times when our minds may <a href="https://theconversation.com/how-your-brain-decides-what-to-think-198109">naturally be more likely to wander</a> anyway.</p> <p>Music is also present during many life events that are distinctive, emotional or self-defining – and <a href="https://theconversation.com/how-your-brain-decides-what-to-think-198109">these types of memories</a> tend to be more easily recalled. </p> <p>Indeed, the power of music to connect us with our past shows how music, memories and emotions are all linked – and it seems certain songs can act as a direct line to our younger selves.</p> <p><em>Image credits: Getty Images</em></p> <p><em>This article originally appeared on <a href="https://theconversation.com/why-does-music-bring-back-memories-what-the-science-says-197301" target="_blank" rel="noopener">The Conversation</a>. </em></p>

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COVID nasal sprays may one day prevent and treat infection

<p>We have vaccines to boost our immune response to SARS-CoV-2, the virus that causes COVID. We have medicines you can take at home (and in hospital) to treat COVID. Now researchers are trialling something new.</p> <p>They want to develop drugs that stop the virus getting into the body in the first place. That includes nasal sprays that stop the virus attaching to cells in the nose.</p> <p>Other researchers are looking at the potential for nasal sprays to stop the virus replicating in the nose, or to make the nose a hostile place to enter the body.</p> <p>Here’s where the science is up to and what we can expect next.</p> <h2>How could we block the virus?</h2> <p>“Viral blockade”, as the name suggests, is a simple premise based on blocking SARS-CoV-2. In other words, if something gets in its way, the virus cannot attach to a cell and it can’t infect you.</p> <p>As SARS-CoV-2 is a respiratory virus, it makes sense to deliver this type of medicine where the virus mainly enters the body – via the nose, in a nasal spray.</p> <p>There are various groups around the world working on this concept. Some research is still being conducted in the lab. Some agents have progressed to preliminary human trials. None are yet available for widespread use.</p> <p><strong>Heparin</strong></p> <p>Heparin is a common medicine that’s been used for decades to thin the blood. Studies in mice show that when heparin is delivered via the nose, <a href="https://link.springer.com/article/10.1007/s11095-022-03191-4" target="_blank" rel="noopener">it’s safe</a> and <a href="https://journals.asm.org/doi/10.1128/JVI.01987-20" target="_blank" rel="noopener">effective</a> in preventing the virus binding to nose cells. Researchers believe heparin binds to the virus itself and stops the virus attaching to the cells it’s trying to infect.</p> <p>A <a href="https://clinicaltrials.gov/ct2/show/NCT05204550" target="_blank" rel="noopener">clinical trial</a> is being <a href="https://www.premier.vic.gov.au/covid-nasal-spray-treatment-clinical-trials-begin" target="_blank" rel="noopener">conducted in Victoria</a> in collaboration between multiple Melbourne-based research centres and the University of Oxford.</p> <p><strong>Covixyl-V</strong></p> <p>Covixyl-V (ethyl lauroyl arginine hydrochloride) is another nasal spray <a href="https://assets.researchsquare.com/files/rs-911449/v1/0577f1f1-56f8-476f-97f6-d27d332ea9ca.pdf?c=1643375660" target="_blank" rel="noopener">under development</a>. It aims to prevent COVID by blocking or modifying the cell surface to prevent the virus from infecting.</p> <p>This compound has been explored for use in various viral infections, and <a href="https://assets.researchsquare.com/files/rs-911449/v1/0577f1f1-56f8-476f-97f6-d27d332ea9ca.pdf?c=1643375660" target="_blank" rel="noopener">early studies</a> in cells and small animals has shown it can prevent attachment of SARS-CoV-2 and reduce the overall viral load.</p> <p><strong>Iota-carrageenan</strong></p> <p>This molecule, which is extracted from seaweed, acts by blocking virus entry into <a href="https://www.frontiersin.org/articles/10.3389/fviro.2021.746824/full" target="_blank" rel="noopener">airway cells</a>.</p> <p>One study of about 400 health-care workers suggests a nasal spray may reduce the incidence of COVID <a href="https://www.dovepress.com/efficacy-of-a-nasal-spray-containing-iota-carrageenan-in-the-postexpos-peer-reviewed-fulltext-article-IJGM" target="_blank" rel="noopener">by up to 80%</a>.</p> <p><strong>IGM-6268</strong></p> <p>This is <a href="https://www.nature.com/articles/s41586-021-03673-2" target="_blank" rel="noopener">an engineered antibody</a> that binds to SARS-CoV-2, <a href="https://www.sciencedaily.com/releases/2021/06/210603171306.htm" target="_blank" rel="noopener">blocking</a> the virus from attaching to cells in the nose.</p> <p>A nasal and oral (mouth) spray are in a clinical trial <a href="https://clinicaltrials.gov/ct2/show/NCT05184218?term=IGM-6268&amp;draw=2&amp;rank=2" target="_blank" rel="noopener">to assess safety</a>.</p> <p><strong>Cold atmospheric plasma</strong></p> <p>This is a gas that contains charged particles. At cold temperatures, it can <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165322" target="_blank" rel="noopener">alter the surface</a> of a cell.</p> <p>A <a href="https://www.thno.org/v12p2811.htm" target="_blank" rel="noopener">lab-based study</a> shows the gas changes expression of receptors on the skin that would normally allow the virus to attach. This results in less SARS-CoV-2 attachment and infection.</p> <p>Scientists now think this technology could be adapted to a nasal spray to prevent SARS-CoV-2 infection.</p> <h2>How could we stop the virus replicating?</h2> <p>Another tactic is to develop nasal sprays that stop the virus replicating in the nose.</p> <p>Researchers are designing genetic fragments that bind to the viral RNA. These fragments – known as “<a href="https://www.nature.com/articles/s41467-022-32216-0" target="_blank" rel="noopener">locked nucleic acid antisense oligonucleotides</a>” (or LNA ASOs for short) – put a proverbial spanner in the works and stop the virus from replicating.</p> <p>A spray of these genetic fragments delivered into the nose <a href="https://www.nature.com/articles/s41467-022-32216-0" target="_blank" rel="noopener">reduced virus replication in the nose</a> and prevented disease in small animals.</p> <h2>How could we change the nose?</h2> <p>A third strategy is to change the nose environment to make it less hospitable for the virus.</p> <p>That could be by using a nasal spray to change moisture levels (with saline), alter the pH (making the nose more acidic or alkaline), or adding a virus-killing agent (iodine).</p> <p>Saline can reduce the amount of <a href="https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2768627" target="_blank" rel="noopener">SARS-CoV-2 in the nose</a> by simply washing away the virus. One study has even found that saline nasal irrigation <a href="https://journals.sagepub.com/doi/10.1177/01455613221123737" target="_blank" rel="noopener">can lessen COVID disease</a> severity. But we would need further research into saline sprays.</p> <p>An Australian-led study has found that an iodine-based nasal spray <a href="https://www.theajo.com/article/view/4466/html" target="_blank" rel="noopener">reduced the viral load</a> in the nose. Further <a href="https://www.uwa.edu.au/news/Article/2022/February/Study-finds-nasal-spray-could-aid-battle-against-COVID" target="_blank" rel="noopener">clinical trials</a> are planned.</p> <p><a href="https://www.sciencedirect.com/science/article/pii/S1386653222001809#!" target="_blank" rel="noopener">One study</a> used a test spray – containing ingredients including eucalyptus and clove oils, potassium chloride and glycerol. The aim was to kill the virus and change the acidity of the nose to prevent the virus attaching.</p> <p>This novel formulation has been tested in the lab and in a <a href="https://www.sciencedirect.com/science/article/pii/S1386653222001809#!" target="_blank" rel="noopener">clinical trial</a> showing it to be safe and to reduce infection rate from about 34% to 13% when compared to placebo controls.</p> <h2>Barriers ahead</h2> <p>Despite promising data so far on nasal sprays for COVID, one of the <a href="https://www.nature.com/articles/d41586-022-03341-z" target="_blank" rel="noopener">major barriers</a> is keeping the sprays in the nose.</p> <p>To overcome this, most sprays need multiple applications a day, sometimes every few hours.</p> <p>So based on what we know so far, nasal sprays will not singlehandedly beat COVID. But if they are shown to be safe and effective in clinical trials, and receive regulatory approval, they might be another tool to help prevent it.</p> <p><strong>This article originally appeared on <a href="https://theconversation.com/covid-nasal-sprays-may-one-day-prevent-and-treat-infection-heres-where-the-science-is-up-to-193840" target="_blank" rel="noopener">The Conversation</a>.</strong></p> <p><em>Image: Shutterstock</em></p>

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