tag:theconversation.com,2011:/uk/topics/zinc-2105/articlesZinc – The Conversation2023-12-12T15:59:00Ztag:theconversation.com,2011:article/2195442023-12-12T15:59:00Z2023-12-12T15:59:00ZThrush: zinc may prevent yeast infections – new research<figure><img src="https://images.theconversation.com/files/565180/original/file-20231212-15-6dcsbr.jpg?ixlib=rb-1.1.0&rect=32%2C10%2C7156%2C4031&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The majority of yeast infections are caused by _Candida albicans_.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/candida-fungi-albicans-c-auris-other-1810949326">Kateryna Kon/ Shutterstock</a></span></figcaption></figure><p>Around half a billion women experience a vaginal yeast infection (thrush) every year – with around 140 million women suffering from multiple infections <a href="https://gaffi.org/wp-content/uploads/Denning-Recurrent-VVC-global-burden-Lancet-Infect-Dis-2018.pdf">throughout their lifetime</a>. </p>
<p>While treatments do exist for thrush, for many women these aren’t effective (or they only have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10455317/">short-term effects</a>). But new research has discovered that zinc could be used to <a href="https://www.science.org/doi/10.1126/scitranslmed.adi3363">treat vaginal yeast infections</a> by limiting how the fungus grows in the vagina.</p>
<p>The majority of vaginal yeast infections are caused by the fungus <a href="https://pubmed.ncbi.nlm.nih.gov/26690853/"><em>Candida albicans</em></a>. For most of us, this fungus exists as a normal part of our microbiome and is harmless. But when the microbiome is disturbed (for example, as a result of <a href="https://pubmed.ncbi.nlm.nih.gov/35568028/">antibiotic use</a>), this can change how <em>C. albicans</em> grows – making it more likely to cause an infection.</p>
<p>This fungus has also evolved strategies to help it acquire the nutrients it needs to grow, even in the harsh environments of mammalian tissues. In the human vagina, for example, the fungus finds itself in an environment that’s acidic, with lots of competition from local bacteria for nutrients. </p>
<p>One <a href="https://www.frontiersin.org/articles/10.3389/fmicb.2017.02238/full">key nutrient</a> this fungus needs to grow and multiply is the metal zinc. When <em>C. albicans</em> cannot find zinc in its immediate surroundings, it instead makes a protein called Pra1 that helps it find the metal in nearby cells and the vaginal mucus. This was one of the key findings of this latest study.</p>
<p>The researchers also found that in women who had a vaginal yeast infection caused by <em>C. albicans</em>, the levels of inflammation in the vagina were higher than in women who did not have thrush. This meant their immune system was activated against the fungi.</p>
<p>These inflammation levels also positively correlated with the amount of Pra1 produced. This is important, because inflammation causes many of the <a href="https://www.cdc.gov/fungal/diseases/candidiasis/genital/index.html">symptoms of thrush</a> – including itching, a burning feeling and swelling. </p>
<p>Since Pra1, rather than <em>C. albicans</em> itself, appeared to be causing many of the symptoms of thrush, the researchers then wondered whether adding zinc back into the vagina would stop the fungus making Pra1 and thus reduce inflammation. </p>
<p>They gave a commercially available vaginal gel that contains zinc (currently used for vaginal dryness) to six women who had experienced multiple yeast infections. The women self-applied the gel every night for two weeks, followed by twice a week thereafter for up to three months.</p>
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<img alt="A woman suffering with an uncomfortable yeast infection." src="https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565183/original/file-20231212-30-neishp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The Pra1 protein appeared to be causing many of the uncomfortable thrush symptoms.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vaginal-urinary-incontinence-pain-asian-young-2167998705">Kmpzzz/ Shutterstock</a></span>
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<p>The results showed that the zinc-containing gel stopped the symptoms of thrush in five of the six women. While this still needs to be tested in a bigger group, the results are promising – and may provide a new way to treat vaginal yeast infections, particularly for recurrent sufferers.</p>
<p>Exactly how the zinc gel works to stop yeast infections needs to be figured out. But it’s likely because providing the fungus with enough zinc stops it producing Pra1. This in turn reduces inflammation – and symptoms.</p>
<p>So instead of getting rid of the fungus, the gel may be helping the fungus to grow alongside the other microbes that make up the vaginal microbiome in a more balanced, harmonious way. </p>
<h2>Heavy metals</h2>
<p>Many fungi that cause infections in humans make proteins to help them grow when nutrients, such as zinc or copper, are in short supply. Pra1 is one example. </p>
<p>Another is the fungus <em>Cryptococcus neoformans</em>, which causes meningitis in people with Aids. This fungus makes a protein called Ctr4, which helps it grow even when copper levels are limited. Our <a href="https://www.nature.com/articles/s41467-023-43061-0">recent work</a> also showed that <em>C. neoformans</em> will hide inside the brain’s immune cells in order to find copper, helping to promote infection. </p>
<p>But when we deleted Ctr4 from the fungus’s genes, this limited how much the fungus was able to grow – helping to <a href="https://www.nature.com/articles/ncomms6550">prevent brain infection</a>.</p>
<p>Zinc and copper are not only important for how fungi grow – they’re also important <a href="https://pubmed.ncbi.nlm.nih.gov/37905492/">metals that help our immune system</a>. Zinc can fuel the killer functions of neutrophils, a type of immune cell that detects and destroys bacteria and fungi.</p>
<p>Copper helps maintain the number of immune cells in your blood. It’s also found within <a href="https://pubs.acs.org/doi/10.1021/acs.chemrev.0c00921">anti-microbial peptides</a> – small proteins in your saliva and gut that protect against invading microbes.</p>
<p>Because our immune cells use metals to function, they can be rich sources of these nutrients. Some microbes, such as <em>C. neoformans</em>, may target immune cells to acquire these nutrients, as can bacteria that live inside our immune cells – including <em>Mycobacteria</em>,which causes <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521620/">tuberculosis</a>. Immune cells will sometimes attempt to limit a microbe’s access to these nutrients to prevent infection, a process known as “<a href="https://www.nature.com/articles/s41579-022-00745-6">nutritional immunity</a>”.</p>
<p>Given the way metals can influence the outcome of infections and immune responses, it’s no wonder there’s growing interest in this aspect of immunology research.</p>
<p>Better understanding how metals can be used to prevent and treat thrush could have a significant benefit for all who suffer from it. Vaginal thrush is one of the most common fungal infections worldwide. It is associated with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6409199/">high economic cost</a>, due to the amount of drugs needed to treat recurrent infections and loss of productivity due to time off work. Moreover, recurrent thrush causes a <a href="https://link.springer.com/article/10.1186/s12955-016-0470-2">poor quality of life</a> for patients.</p>
<p>Antifungal drug resistance is also a growing problem. The development of drug resistance in the <em>C. albicans</em> fungus can be one reason that <a href="https://pubmed.ncbi.nlm.nih.gov/36866967/">standard treatments don’t work</a> for some women.</p>
<p>Harnessing what we’ve learned from recent studies that have examined how fungi use and acquire nutrients to cause infection can help us identify new strategies to treat not only thrush, but other fungal infections which are a growing problem <a href="https://www.who.int/publications/i/item/9789240060241">around the world</a>.</p><img src="https://counter.theconversation.com/content/219544/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca A. Drummond receives funding from the Medical Research Council. </span></em></p>One study found a zinc-containing gel stopped symptoms of thrush in the majority of women.Rebecca A. Drummond, Associate Professor, Immunology and Immunotherapy, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2113282023-09-12T21:45:51Z2023-09-12T21:45:51ZHow zinc-ion batteries may solve our renewable energy storage problem<iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/how-zinc-ion-batteries-may-solve-our-renewable-energy-storage-problem" width="100%" height="400"></iframe>
<p><a href="https://www.economist.com/leaders/2023/07/20/how-cities-can-respond-to-extreme-heat">Hotter summers</a>, <a href="https://www.bbc.com/future/article/20230612-did-climate-change-cause-canadas-wildfires">drier forests</a>, <a href="https://abcnews.go.com/US/climate-change-rising-sea-levels-transforming-coastlines-world/story?id=91681973">rising waters</a>: climate change is not just a threat to our future, it’s hurting our world right now. </p>
<p>While there are many ways human activity has brought about climate change, <a href="https://www.iea.org/reports/co2-emissions-in-2022">global electricity generation sources are among the leading culprits</a>. <a href="https://www.iea.org/reports/world-energy-outlook-2022">Despite small upticks in the supply of wind and solar power</a>, we have not yet reached a point where we are able to dislodge the fossil fuels that are entrenched in the power mix of many countries. </p>
<p>But why is this still the case? </p>
<p>Since renewable sources deliver an intermittent supply of power, we also need a way to store this energy to meet the demand of the grid when the sun is not shining, or the wind is not blowing. This is a major challenge, as the switch to renewable power also requires establishing long lasting, safe and affordable energy storage systems. As such, finding a cheap, safe and alternative battery to lithium is the key to moving the needle to a completely renewable power sector. </p>
<h2>Beyond lithium-ion batteries</h2>
<p>As with electric vehicles, lithium-ion batteries have become a popular option for the grid, as they offer a high energy density, modular solution for energy storage. But the use of lithium-ion batteries has also brought along its own challenges with high cost of materials, risk of fire and explosion and lack of recycling practices limiting the widespread adoption of lithium-ion batteries for the grid. </p>
<p>One incredibly promising option to replace lithium for grid scale energy storage is the <a href="https://doi.org/10.1016/j.joule.2023.06.007">rechargeable zinc-ion battery</a>. <a href="https://doi.org/10.1038/nenergy.2016.119">Emerging only within the last 10 years</a>, zinc-ion batteries offer many advantages over lithium. These include cheaper material costs, increased safety and easier recycling options. </p>
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Read more:
<a href="https://theconversation.com/batteries-are-the-environmental-achilles-heel-of-electric-vehicles-unless-we-repair-reuse-and-recycle-them-205404">Batteries are the environmental Achilles heel of electric vehicles – unless we repair, reuse and recycle them</a>
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<p>With grid-scale energy storage potential at a considerably cheaper cost — and higher levels of safety — widespread commercialization of zinc-ion batteries could be exactly what is needed to integrate renewables into energy infrastructure in Canada and other countries.</p>
<h2>The cost of a battery</h2>
<p>For Canada to reach the decarbonization targets set in the Canadian <a href="https://www.canada.ca/en/services/environment/weather/climatechange/climate-plan/net-zero-emissions-2050/canadian-net-zero-emissions-accountability-act.html">Net-Zero Emissions Accountability Act</a>, <a href="https://www.iea.org/reports/canada-2022/executive-summary">including a grid powered by 90 per cent renewable electricity</a>, the deployment of zinc-ion batteries will be crucial. </p>
<p>Studies have shown that for renewables to become the source of 90 to 95 per cent of all electricity, <a href="https://doi.org/10.1016/j.joule.2019.06.012">the cost of energy storage must be below US$150/kWh</a>. Modern lithium-ion systems are <a href="https://www.pnnl.gov/lithium-ion-battery-lfp-and-nmc">still sitting around US$350/kWh</a>. In part, this is due to high manufacturing costs and their reliance on expensive raw materials to achieve the high energy density needed for <a href="https://doi.org/10.1038/s41560-018-0130-3">modern electric vehicles</a>.</p>
<p>Zinc-ion batteries on the other hand, could solve the cost and abundance issues. Using inexpensive, abundant materials such as zinc and manganese not only makes them cheaper to produce, but lowers risk from supply chain disruptions or material shortages that affect lithium-ion materials such as lithium and <a href="https://doi.org/10.1016/j.isci.2020.101505">cobalt</a>. </p>
<p>The <a href="https://natural-resources.canada.ca/our-natural-resources/minerals-mining/minerals-metals-facts/zinc-facts/20534">annual production of zinc</a> globally is <a href="https://natural-resources.canada.ca/our-natural-resources/minerals-mining/minerals-metals-facts/lithium-facts/24009">over 100 times that of lithium</a>. Not to mention that <a href="https://earth911.com/eco-tech/recycling-critical-minerals-for-circular-clean-energy-solutions/">demand for lithium and cobalt is anticipated to outweigh the supply within the next decade</a>.</p>
<h2>Zinc is a safer option</h2>
<p>With <a href="https://www.ul.com/news/ul-9540-energy-storage-system-ess-requirements-evolving-meet-industry-and-regulatory-needs">rigorous safety standards</a> being created for batteries used in homes, factories or within the electrical grid, safety is key to getting the public to embrace them. In this way, zinc-ion batteries offer further advantage. </p>
<p>The <a href="https://www.pv-magazine.com/2021/04/21/two-firefighters-killed-and-one-missing-after-beijing-battery-blaze/">flammable and toxic solvent based electrolyte of lithium-ion batteries</a> is replaced with a water-based alternative, removing the risk of fire and explosion. </p>
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Read more:
<a href="https://theconversation.com/we-could-need-6-times-more-of-the-minerals-used-for-renewables-and-batteries-how-can-we-avoid-a-huge-increase-in-mining-impacts-206864">We could need 6 times more of the minerals used for renewables and batteries. How can we avoid a huge increase in mining impacts?</a>
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<p>Conversely, the safe disposal of lithium-ion batteries can also be a difficult task, as they contain toxic compounds. <a href="https://doi.org/10.1002/cey2.29">Recycling these batteries is currently economically infeasible due to high costs</a> leading to large numbers of spent cells ending up in landfills. </p>
<p>Fortunately, <a href="https://doi.org/10.1002/adsu.202100308">zinc-ion batteries simplify end of life treatment</a>. The nontoxic, aqueous electrolyte used in zinc-ion batteries means that <a href="https://www.reuters.com/business/sustainable-business/key-facts-about-used-lead-acid-battery-recycling-2021-04-20/">well established methods like those for lead-acid battery disposal</a> can be used. Also, the metallic zinc anode could be easily reused in new batteries. </p>
<h2>The future of energy storage</h2>
<p>To reach its goal of 90 per cent renewable energy by 2030, Canada must look for alternatives to lithium-ion batteries to enable decarbonization of its power sector. Leveraging the cost, abundance and safety benefits of zinc-ion batteries, Canada can accelerate the integration of wind and solar power across the nation. </p>
<p>Zinc-ion batteries support Canada’s decarbonization goals and prove an opportunity to capitalize on a rapidly expanding battery market. While zinc-ion batteries are a relatively new technology, their potential to support grid scale energy storage within Canada and worldwide cannot be understated. </p>
<p>With the help of Canadian research and manufacturing, including efforts from <a href="https://brighterworld.mcmaster.ca/articles/drew-higgins-clean-energy-low-carbon-electricity-canada-green-tech/">McMaster University</a> and Dartmouth, N.S.-based <a href="https://salientenergyinc.com/">Salient Energy Inc.</a>, the integration of zinc-ion batteries could become a reality within the next several years, establishing Canada as an industry leader.</p><img src="https://counter.theconversation.com/content/211328/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Storm William D Gourley receives funding from the Natural Sciences and Engineering Research Council of Canada (NSERC). </span></em></p><p class="fine-print"><em><span>Drew Higgins' research program at McMaster University receives funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) Alliance grant program and Salient Energy Inc. to develop new battery electrode materials. </span></em></p>Lithium-ion batteries are holding back the full-scale decarbonization of Canada’s energy grid. Zinc-ion batteries may be the solution.Storm William D Gourley, PhD Candidate, Chemical Engineering, McMaster UniversityDrew Higgins, Assistant Professor, Department of Chemical Engineering, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1830832022-05-17T18:59:18Z2022-05-17T18:59:18ZZinc is a metal essential to life – scientists have discovered a protein that helps keep cells alive when zinc levels are low<figure><img src="https://images.theconversation.com/files/463386/original/file-20220516-19-5mwuzq.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C2111%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A protein called ZNG1 helps cells make use of zinc when stores of this essential nutrient are running low.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/zinc-mine-nugget-royalty-free-image/163263590">bagi1998/E+ via Getty Images</a></span></figcaption></figure><p>All living things, including people, need zinc in their diets. Getting too little of this <a href="https://www.ncbi.nlm.nih.gov/books/NBK493231/">essential metal</a> can impair growth and cause immune dysfunction, neurological disorders and cancer. Unfortunately, <a href="https://doi.org/10.1371/journal.pone.0050568">over 17% of the world’s population</a> is at risk for zinc deficiency. The World Health Organization considers this kind of <a href="https://www.who.int/news-room/fact-sheets/detail/malnutrition">micronutrient-related malnutrition</a> a leading contributor to disease and death.</p>
<p>After you eat a meal, zinc is taken up by the cells of your body. Inside each cell, zinc <a href="https://doi.org/10.1021/pr050361j">binds to proteins</a> to support their structure and function. Researchers estimate that up to 10% of all proteins need zinc to properly function. In this sense, a zinc protein without zinc is similar to a car without an engine or without screws holding it together: It either might not work or disassemble completely. </p>
<p>Despite zinc’s importance to human health, several aspects of how it supports cellular processes aren’t completely understood, including how it’s incorporated into the proteins essential for cell function in the first place. </p>
<p>As <a href="https://scholar.google.com/citations?user=aPlke6sAAAAJ&hl=en">researchers</a> <a href="https://scholar.google.com/citations?hl=en&user=Vc7LnewAAAAJ">who study</a> how metals work in biological systems such as the human body, we wanted to understand how zinc is distributed within a cell. Which proteins in the cell get zinc first, especially if there isn’t enough to go around? How does zinc get to these important proteins? </p>
<p>With our colleagues in the <a href="https://www.vumc.org/skaar-lab/laboratory-eric-skaar-phd-mph">Skaar Lab</a> at Vanderbilt University Medical Center and the <a href="https://giedroc.lab.indiana.edu/">Giedroc Lab</a> at Indiana University, we recently identified the <a href="http://dx.doi.org/10.1016/j.cell.2022.04.011">first known molecule</a> that delivers zinc to crucial proteins.</p>
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<figcaption><span class="caption">Zinc is a micronutrient you can’t live without.</span></figcaption>
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<h2>Delivering zinc to where it needs to go</h2>
<p>We started by investigating the molecules a cell produces when zinc levels are low. One family of proteins seemed particularly interesting because it looked as if it could be a potential <a href="https://doi.org/10.1016/s1074-5521(02)00156-4">metallochaperone</a>, a protein that selectively inserts metals, such as zinc and iron, into other proteins. We named this protein family ZNG1.</p>
<p>As it turns out, <a href="https://doi.org/10.1186/1471-2164-10-470">all vertebrates</a> have the gene that directs cells to produce ZNG1. While ZNG1 interacts with several proteins that bind zinc, one in particular, a protein called <a href="https://doi.org/10.1074/mcp.RA117.000360">METAP1</a>, caught our attention. METAP1 is known to activate many other essential proteins within the cell. Cells without functioning METAP proteins cannot survive. </p>
<p>We were intrigued by METAP1 because it interacts with ZNG1 proteins across species – among them zebrafish, mice and people. The finding suggests that the connection between these two proteins has been maintained for over 400 million years of evolution, meaning that the ZNG1’s supportive role in METAP1 function is important in all organisms that produce these proteins.</p>
<p>To study the role ZNG1 plays in animal health, we mutated the gene coding for ZNG1 in mice and zebrafish. When animals without ZNG1 were deprived of zinc, they either failed to grow or displayed developmental defects. Although the animals still have trace amounts of zinc available, they were unable to use the zinc correctly. This confirmed that ZNG1 helps METAP1 function properly, likely by helping it bind to or use zinc.</p>
<p>Using molecular imaging and other methods, we also observed that the energy-producing mitochondria of zinc-starved mouse cells without working ZNG1 proteins were not functioning correctly. This highlights ZNG1’s importance during periods of zinc deficiency by helping the cell allocate trace levels of this essential metal to the mitochondria and ultimately sustain cellular energy production.</p>
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<a href="https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Variety of zinc-rich foods laid out on a white table" src="https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463692/original/file-20220517-15-ku0913.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Zinc-rich foods include a variety of meats, nuts and legumes, eggs and whole grains.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/foods-high-in-zinc-royalty-free-image/1189476693">bit245/iStock via Getty Images Plus</a></span>
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<h2>ZNG1 may hold the key to zinc deficiency</h2>
<p>We believe this research is just the first step to better understand how zinc metallochaperones maintain health and cellular function when zinc levels are low. </p>
<p>We hypothesize that ZNG1 supports the function of additional zinc-dependent proteins in the cell. In that way, ZNG1 would be the gatekeeper that distributes zinc to a network of essential proteins, ultimately allowing an organism to survive even if dietary zinc is limited.</p>
<p>This research paves the way to understanding how cells use zinc during periods of malnourishment or zinc deficiency. Further research on the proteins to which ZNG1 preferentially gives zinc when there isn’t enough available could help identify which cellular processes are most crucial to sustain life when zinc is limited. This in turn could help in the fight against the negative health consequences of zinc deficiency.</p><img src="https://counter.theconversation.com/content/183083/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andy Weiss receives funding from the American Heart Association Postdoctoral Fellowship and National Institutes of Health T32 and F32 fellowships.</span></em></p><p class="fine-print"><em><span>Caitlin Murdoch receives funding from National Institutes of Health T32 and F32 fellowships</span></em></p>While iron and calcium are the metals that get the most attention, zinc is also important for human health and function.Andy Weiss, Postdoctoral Fellow in Pathology, Microbiology and Immunology, Vanderbilt UniversityCaitlin Murdoch, Postdoctoral Researcher in Pathology, Microbiology and Immunology, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1822202022-05-09T20:00:05Z2022-05-09T20:00:05ZCan taking vitamins and supplements help you recover from COVID?<figure><img src="https://images.theconversation.com/files/461709/original/file-20220506-12965-zm9rtl.jpg?ixlib=rb-1.1.0&rect=19%2C9%2C6410%2C3711&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://image.shutterstock.com/image-photo/supporting-immune-system-season-flu-600w-1835540941.jpg">Shutterstock</a></span></figcaption></figure><p>Australia’s <a href="https://www.abc.net.au/news/2020-03-17/coronavirus-cases-data-reveals-how-covid-19-spreads-in-australia/12060704">surge in COVID cases</a> this year has seen many people looking for ways to protect themselves or boost their immunity and recovery. An upswing in sales of dietary supplements has followed.</p>
<p>In Australia, the Therapeutic Goods Administration includes vitamins, minerals, amino acids, enzymes, plant extracts and microbiome supplements under the term “<a href="https://www.tga.gov.au/node/4233">complementary medicine</a>”.</p>
<p>The supplement industry’s <a href="https://www.globenewswire.com/news-release/2020/07/29/2069678/0/en/Global-Dietary-Supplements-Industry.html">global estimated worth</a> was about US $170 billion (A$239 billion) in 2020. Australian complementary medicines revenue was estimated at A$5.69 billion in 2021 – <a href="https://www.cmaustralia.org.au/page-1859595">doubling in size</a> over the past decade. The latest data shows 73% of Australians <a href="https://www.statista.com/statistics/1285506/australia-leading-complementary-medicines-purchased/">bought complementary medicines</a> in the previous year, with vitamins featuring in more than half of purchases.</p>
<p>But how likely are these purchases to be effective in preventing COVID or treating it?</p>
<h2>Fear, avoidance and laboratory studies</h2>
<p>Historically, the public has purchased supplements from sources that also provide health-care advice. Lockdowns and blanket health messages about social distancing and personal hygiene have created a new normal. So people are doing more shopping online for supplements and turning to the internet, friends or social media for vitamin recommendations. For some, this has led to an unhealthy fear of COVID (<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7474809/">coronaphobia</a>) and negative impacts on daily life.</p>
<p>As with any medicine, consumers should seek information from reliable sources (doctors, pharmacists or evidence-based peer-reviewed articles) about the potential benefits and harms of supplements before purchase. Strong evidence <a href="https://www.nejm.org/doi/full/10.1056/NEJMoa2119451">supports</a> vaccination as effective against the acute respiratory symptoms of COVID. <a href="https://pubmed.ncbi.nlm.nih.gov/32334392/">Researchers</a> have also looked at whether supplements may prevent or reduce the duration and severity of this viral infection by boosting the immune response.</p>
<p>Deficiencies in essential nutrients that support immune function (vitamin C, vitamin D, zinc and selenium) <a href="https://pubmed.ncbi.nlm.nih.gov/35063248/">have been shown</a> to increase susceptibility to infection, including COVID. But there is <a href="https://pubmed.ncbi.nlm.nih.gov/34626488/">little evidence</a> supplementation in a healthy person prevents respiratory infections such as COVID. An evidence gap <a href="https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776299">exists</a> between a supplement’s action in laboratory or animal studies and findings from well designed and conducted clinical trials. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="couple browse vitamin aisle in supermarket" src="https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461710/original/file-20220506-23-ez6sya.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The dietary supplementary industry has doubled in size over the last decade.</span>
<span class="attribution"><a class="source" href="https://image.shutterstock.com/image-photo/couple-doing-their-groceries-supermarket-600w-573335551.jpg">Shutterstock</a></span>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/no-cbd-is-not-a-miracle-molecule-that-can-cure-coronavirus-just-as-it-wont-cure-many-other-maladies-its-proponents-claim-132492">No, CBD is not a miracle molecule that can cure coronavirus, just as it won't cure many other maladies its proponents claim</a>
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</em>
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<h2>A pandemic ‘infodemic’</h2>
<p>Ready access to supplements without a prescription from a myriad of online and shopfront sources and the <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0266705">uncontrolled spread of claims</a> that supplements can prevent or treat COVID symptoms, has created an “<a href="https://www.who.int/health-topics/infodemic#tab=tab_1">infodemic</a>”. </p>
<p>These claims are fuelled by supplement manufacturers being able to <a href="https://www.tga.gov.au/node/4233">“list” their products</a> on the Australian Register of Therapeutic Goods, with limited evidence of safety or effectiveness. This appearance of official approval tallies with the common <a href="https://www.tandfonline.com/doi/abs/10.3109/13697139909025568">misperception</a> that “natural” means “safe”. </p>
<p>Supplements can cause <a href="https://www.tandfonline.com/doi/abs/10.3109/13697139909025568">harm</a> in the form of adverse effects, drug interactions and expense. They also add to a patient’s <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165107/#:%7E:text=The%20concept%20of%20%E2%80%9Cmedication%2Drelated,19%2C20%2C21%5D.">medication burden</a>, may delay more effective therapy, or give false hope to the vulnerable.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/lemon-water-wont-detox-or-energise-you-but-it-may-affect-your-body-in-other-ways-180035">Lemon water won't detox or energise you. But it may affect your body in other ways</a>
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<h2>Vitamins A to zinc</h2>
<p>The recent <a href="https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776305">COVID A to Z Study</a> illustrates some of the challenges involved. </p>
<p>It was designed to test the effectiveness of high-dose zinc, vitamin C, and a combination of both, to shorten the duration of COVID-related symptoms compared with usual care in adult outpatients with confirmed infection. </p>
<p>These nutrients <a href="https://pubmed.ncbi.nlm.nih.gov/32334392/">were chosen</a> because:</p>
<ul>
<li>vitamin C studies in mice showed this antioxidant to be essential for antiviral immune responses against the influenza A virus, especially in the early stages of the infection</li>
<li>deficiency of zinc, an essential trace element, has been associated with increased susceptibility to viral infections.</li>
</ul>
<p>The authors planned to include 520 patients but the safety monitoring committee recommended the study be stopped early, due to low likelihood of detecting significant outcome differences between the groups. There were also more adverse effects (nausea, diarrhoea, and stomach cramps) reported in the supplement groups than those receiving usual care.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1519613353286590464"}"></div></p>
<h2>Little evidence of benefits</h2>
<p>Despite the large variety of complementary medicines marketed, most clinical trials to date have studied the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8873042/">impact of vitamin D</a>, <a href="https://clinicalnutritionespen.com/article/S2405-4577(22)00002-X/fulltext">vitamin C or zinc</a> to reduce the risk of contracting COVID, improve rates of hospitalisation or death. </p>
<p>Even with high treatment doses, results have been <a href="https://ods.od.nih.gov/factsheets/COVID19-HealthProfessional/#h2">generally disappointing</a>. Vitamin D, zinc and some probiotics <em>may</em> be beneficial to <em>prevent</em> viral infections. Vitamins D, C, A, zinc, calcium and some probiotics <em>may</em> be beneficial to <em>treat</em> viral infections. But other supplements studied (including copper, magnesium, selenium and echinacea) are unlikely to be beneficial or are not supported by sufficient data. </p>
<p>However, supplements may be beneficial when individuals are <a href="https://pubmed.ncbi.nlm.nih.gov/32334392/">unable to achieve</a> a balanced and varied diet.</p>
<hr>
<iframe src="https://flo.uri.sh/visualisation/9883728/embed" title="Interactive or visual content" class="flourish-embed-iframe" frameborder="0" scrolling="no" style="width:100%;height:600px;" sandbox="allow-same-origin allow-forms allow-scripts allow-downloads allow-popups allow-popups-to-escape-sandbox allow-top-navigation-by-user-activation" width="100%" height="400"></iframe>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/sugar-detox-cutting-carbs-a-doctor-explains-why-you-should-keep-fruit-on-the-menu-173992">Sugar detox? Cutting carbs? A doctor explains why you should keep fruit on the menu</a>
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<h2>Potentially harmful</h2>
<p>High doses or chronic use of COVID supplements have also been linked with <a href="https://pubmed.ncbi.nlm.nih.gov/20040703/">adverse effects</a>: vitamin D with muscle pain and loss of bone mass; vitamin A with elevated liver function tests and blurred vision; vitamin E with bleeding risk; plant extracts, magnesium with gastrointestinal effects; and selenium with hair loss and brittle nails.</p>
<p>So, the evidence is not convincing that taking vitamins and supplements will prevent you catching COVID or help you recover from the infection, unless you have a known nutrient deficiency or a poor diet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/vitamins-and-minerals-arent-risk-free-here-are-6-ways-they-can-cause-harm-165399">Vitamins and minerals aren't risk-free. Here are 6 ways they can cause harm</a>
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</em>
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<img src="https://counter.theconversation.com/content/182220/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Treasure McGuire does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Sales of vitamins are booming in pandemic times. But is there any evidence that vitamin and mineral supplements can protect you from COVID or help you recover from infection?Treasure McGuire, Assistant Director of Pharmacy, Mater Health SEQ in conjoint appointment as Associate Professor of Pharmacology, Bond University and Associate Professor (Clinical), The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1492292021-01-12T19:43:16Z2021-01-12T19:43:16ZAnti-nutrients – they’re part of a normal diet and not as scary as they sound<figure><img src="https://images.theconversation.com/files/377416/original/file-20210106-13-22nh6o.jpg?ixlib=rb-1.1.0&rect=109%2C97%2C4164%2C2670&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">These compounds occur naturally in a number of healthy foods, including legumes and whole grains.
</span> <span class="attribution"><a class="source" href="https://unsplash.com/s/photos/legumes-whole-grains">foodism360/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Maybe you’re trying to eat healthier these days, aiming to get enough of the good stuff and limit the less-good stuff. You’re paying attention to things like fiber and fat and vitamins… and anti-nutrients?</p>
<p>What the heck are anti-nutrients and are they something you need to be concerned about in your diet?</p>
<p>Let me, as a public health nutrition researcher, reassure you that anti-nutrients aren’t the evil nemesis of all the nutritious foods you eat. As long as you’re consuming a balanced and varied diet, anti-nutrients are not a concern. In fact, scientists are realizing they actually have many health benefits.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="illustration of small intestine amid other organs" src="https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377772/original/file-20210108-21-x8ovnm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nutrients get absorbed into your bloodstream – or not – as digestion occurs in your small intestine.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/small-intestine-illustration-royalty-free-illustration/1190674194">Sebastian Kaulitzki/Science Photo Library via Getty Images</a></span>
</figcaption>
</figure>
<h2>What are anti-nutrients?</h2>
<p><a href="https://www.hsph.harvard.edu/nutritionsource/anti-nutrients/">Anti-nutrients are substances</a> that naturally occur in plant and animal foods.</p>
<p>The name comes from how they function in your body once you eat them. They <a href="https://www.sciencedirect.com/topics/food-science/antinutrients">block or interfere with how your body</a> <a href="https://doi.org/10.1631/jzus.B0710640">absorbs other nutrients</a> out of your gut and into your bloodstream so you can then use them. Thus, anti-nutrients may decrease the amount of nutrients you actually get from your food. They most commonly interfere with the absorption of <a href="https://doi.org/10.1016/j.jand.2016.09.025">calcium, iron, potassium, magnesium and zinc</a>.</p>
<p>Plants evolved these <a href="https://www.todaysdietitian.com/newarchives/070111p54.shtml">compounds as a defensive mechanism</a> against insects, parasites, bacteria and fungi. For example, some anti-nutrients can cause a food to taste bitter; animals won’t want to eat it, leaving the seed, for instance, to provide nourishment for future seedlings. Some anti-nutrients block the digestion of seeds that are eaten. The seeds disperse when they come out the other end in the animal’s fecal matter and can go on to grow new plants. Both of these survival tactics help the plant species grow and spread.</p>
<p>In terms of foods that people eat, you’ll most commonly find anti-nutrients naturally occurring in whole grains and legumes.</p>
<h2>Time for an image makeover as health enhancers</h2>
<p>Despite sounding scary, studies show that anti-nutrients are not of concern unless consumed in <a href="https://doi.org/10.1016/j.jcs.2014.01.010">ultra, unrealistically high amounts</a> – and they have numerous health benefits. </p>
<p>Anti-nutrients are currently undergoing a change in image very similar to the one dietary fiber experienced. At one point, scientists thought dietary fiber was bad for people. Since fiber could bind to nutrients and pull them out of the digestive tract in poop, it seemed like something to avoid. To address this perceived issue, grain processing in the late 1800s removed fiber from foods.</p>
<p>But now scientists know that <a href="https://doi.org/10.1111/j.1753-4887.2009.00189.x">dietary fiber is incredibly important</a> and encourage its consumption. Eating plenty of fiber lowers the risks of obesity, high blood pressure, heart disease, stroke, diabetes and some gastrointestinal diseases.</p>
<p>In the same way, rather than something to avoid, many anti-nutrients are now considered health-promoting nutraceuticals and functional foods due to their numerous benefits. Here’s an introduction to some of the most frequently eaten anti-nutrients that come with benefits:</p>
<ul>
<li><p><a href="https://doi.org/10.1089/109662004322984734">Saponins, common in legumes</a>, can boost the immune system, reduce risk of cancer, lower cholesterol, lower blood sugar response to foods, result in fewer cavities, reduce risk of kidney stones and combat blood clotting seen in heart attacks and strokes.</p></li>
<li><p><a href="https://doi.org/10.1016/j.jcs.2014.01.010">Lectins, found in cereal grains and legumes</a>, are associated with reduced risk of cardiovascular disease, diabetes, some cancers and becoming overweight or obese.</p></li>
<li><p><a href="https://doi.org/10.1080/10408699891274273">Tannins, commonly found in teas, coffees and processed meats and cheeses</a>, are antioxidants that can inhibit growth of bacteria, viruses, fungi and yeast and may decrease cholesterol levels and blood pressure.</p></li>
<li><p><a href="https://doi.org/10.1631/jzus.B0710640">Phytates, found in wheat, barley, rice and corn</a>, are associated with increased immune function and cancer cell death, as well as reduced cancer cell growth and spread. They also have antioxidant properties and can reduce inflammation. </p></li>
<li><p>Finally, <a href="https://doi.org/10.1024/0300-9831.72.1.26">glucosinates, found in brassica vegetables</a> like cauliflower, inhibit tumor cell growth.</p></li>
</ul>
<p>Oxalates are one of the few anti-nutrients with mostly negative impacts on the body. They are <a href="https://www.uofmhealth.org/health-library/aa166321">found in lots of common foods</a>, including legumes, beets, berries, cranberries, oranges, chocolate, tofu, wheat bran, soda, coffee, tea, beer, dark green vegetables and sweet potatoes. The negative impacts of oxalates include binding to calcium in the digestive tract and removing it from the body in bowel movements. Oxalates can also <a href="https://www.uofmhealth.org/health-library/aa166321">increase the risk of kidney stones</a> in some people.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="bowl of chickpea curry" src="https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377773/original/file-20210108-21-17lbxqq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lots of healthy, tasty foods come with the added benefits of anti-nutrients.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/chickpea-and-spinach-curry-royalty-free-image/657152778">Joan Ransley/Moment via Getty Images</a></span>
</figcaption>
</figure>
<h2>Fitting anti-nutrients into a healthy diet</h2>
<p>Overall, comparing the benefits to the drawbacks, anti-nutrient pros actually outweigh the cons. The healthy foods that contain them – mainly fruits, vegetables, whole grains and legumes – should be encouraged not avoided.</p>
<p>Anti-nutrients become a concern only if these foods are consumed in ultra-high amounts, <a href="https://www.ars.usda.gov/research/project/?accnNo=426312">which is very unlikely</a> for most adults and children in the U.S. Additionally, a large proportion of anti-nutrients are removed or lost from foods people eat <a href="https://www.hsph.harvard.edu/nutritionsource/anti-nutrients/">as they’re processed and cooked</a>, especially if soaking, blanching, boiling or other high-heat processes are involved.</p>
<p>Vegetarians and vegans may be at higher risk of negative effects from anti-nutrients because their diet relies heavily on fruits, vegetables, whole grains and legumes. But these <a href="https://doi.org/10.1016/j.jand.2016.09.025">plant-based diets are still among the healthiest</a> and are associated with reduced risk of cardiovascular disease, obesity, diabetes and numerous types of cancers. </p>
<p>Vegetarians and vegans can take a few steps to help counteract anti-nutrients’ effects on their absorption of particular nutrients:</p>
<ul>
<li><p>Pair high iron <a href="https://doi.org/10.1093/jn/130.5.1378S">and zinc</a> <a href="https://doi.org/10.1016/bs.afnr.2014.11.003">foods with</a> <a href="https://doi.org/10.1093/ajcn/59.5.1233S">foods high in vitamin C</a> (examples: veggie meatballs with tomato sauce, tomato-based chili with beans).</p></li>
<li><p><a href="https://www.jblearning.com/catalog/productdetails/9780763779764?jblsearch">Soak legumes before cooking</a>. </p></li>
<li><p><a href="https://doi.org/10.1093/ajcn/70.3.543s">Time dairy intake</a> such that it is not always paired with high oxalate foods.</p></li>
<li><p>Purchase dairy products that are fortified with calcium.</p></li>
<li><p>Consider a multivitamin-mineral supplement with about 100% of the daily recommended dose of nutrients (check the nutrition facts panel) as nutrition insurance if you are worried, but be sure to talk to your doctor first.</p></li>
</ul>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/149229/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jill Joyce does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Anti-nutrients naturally occur in food and can block the amount of other nutrients available for your body to use. But their effects aren’t all bad, which is why they’re undergoing an image makeover.Jill Joyce, Assistant Professor of Public Health Nutrition, Oklahoma State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1333562020-03-16T19:01:05Z2020-03-16T19:01:05Z5 ways nutrition could help your immune system fight off the coronavirus<figure><img src="https://images.theconversation.com/files/320678/original/file-20200316-18043-1rg6ra8.jpg?ixlib=rb-1.1.0&rect=0%2C6%2C4500%2C2977&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The coronavirus presents many uncertainties, and none of us can completely eliminate our risk of getting COVID-19. But one thing we can do is eat as healthily as possible.</p>
<p>If we do catch COVID-19, our immune system is responsible for fighting it. Research shows improving nutrition helps <a href="https://www.ncbi.nlm.nih.gov/pubmed/15337163">support optimal immune function</a>. </p>
<p>Micronutrients essential to fight infection include vitamins A, B, C, D, and E, and the minerals iron, selenium, and zinc. </p>
<p>Here’s what we know about <a href="https://www.ncbi.nlm.nih.gov/pubmed/30336639">how these nutrients support our immune system</a> and the foods we can eat to get them. </p>
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Read more:
<a href="https://theconversation.com/what-is-a-balanced-diet-anyway-72432">What is a balanced diet anyway?</a>
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<h2>1. Vitamin A</h2>
<p><a href="https://www.healthdirect.gov.au/vitamin-a">Vitamin A</a> maintains the structure of the cells in the skin, respiratory tract and gut. This forms a barrier and is your body’s first line of defence. If fighting infection was like a football game, vitamin A would be your forward line. </p>
<p>We also need vitamin A to help make <a href="https://en.wikipedia.org/wiki/Antibody">antibodies</a> which neutralise the pathogens that cause infection. This is like assigning more of your team to target an opposition player who has the ball, to prevent them scoring. </p>
<p>Vitamin A is found in oily fish, egg yolks, cheese, tofu, nuts, seeds, whole grains and legumes. </p>
<p>Further, vegetables contain <a href="https://en.wikipedia.org/wiki/Beta-Carotene">beta-carotene</a>, which your body can convert into vitamin A. Beta-carotene is found in leafy green vegetables and yellow and orange vegetables like pumpkin and carrots.</p>
<h2>2. B vitamins</h2>
<p><a href="https://www.betterhealth.vic.gov.au/health/HealthyLiving/vitamin-b">B vitamins</a>, particularly B6, B9 and B12, contribute to your body’s first response once it has recognised a pathogen. </p>
<p>They do this by influencing the production and activity of “<a href="https://en.wikipedia.org/wiki/Natural_killer_cell">natural killer</a>” cells. Natural killer cells work by causing infected cells to “implode”, a process called <a href="https://en.wikipedia.org/wiki/Apoptosis">apoptosis</a>. </p>
<p>At a football match, this role would be like security guards intercepting wayward spectators trying to run onto the field and disrupt play.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/320685/original/file-20200316-18086-1i9edys.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fish is a good source of vitamin B6.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>B6 is found in cereals, legumes, green leafy vegetables, fruit, nuts, fish, chicken and meat. </p>
<p>B9 (<a href="https://en.wikipedia.org/wiki/Folate">folate</a>) is abundant in green leafy vegetables, legumes, nuts and seeds and is added to commercial bread-making flour.</p>
<p><a href="https://theconversation.com/have-you-gone-vegan-keep-an-eye-on-these-4-nutrients-107708">B12</a> (cyanocobalamin) is found in animal products, including eggs, meat and dairy, and also in fortified soy milk (check the nutrition information panel). </p>
<h2>3. Vitamins C and E</h2>
<p>When your body is fighting an infection, it experiences what’s called oxidative stress. Oxidative stress leads to the production of <a href="https://en.wikipedia.org/wiki/Reactive_oxygen_species">free radicals</a> which can pierce cell walls, causing the contents to leak into tissues and exacerbating inflammation.</p>
<p><a href="https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/">Vitamin C</a> and <a href="https://www.healthdirect.gov.au/vitamin-e">vitamin E</a> help protect cells from oxidative stress. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/coronavirus-its-time-to-debunk-claims-that-vitamin-c-could-cure-it-132803">Coronavirus: it's time to debunk claims that vitamin C could cure it</a>
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<p>Vitamin C also helps clean up this cellular mess by producing specialised cells to mount an immune response, including <a href="https://en.wikipedia.org/wiki/Neutrophil">neutrophils</a>, lymphocytes and <a href="https://en.wikipedia.org/wiki/Phagocyte">phagocytes</a>. </p>
<p>So the role of vitamin C here is a bit like cleaning up the football ground after the game.</p>
<p>Good sources of vitamin C include oranges, lemons, limes, berries, kiwifruit, broccoli, tomatoes and capsicum. </p>
<p>Vitamin E is found in nuts, green leafy vegetables and vegetables oils.</p>
<h2>4. Vitamin D</h2>
<p>Some immune cells need <a href="https://www.betterhealth.vic.gov.au/health/HealthyLiving/vitamin-d">vitamin D</a> to help destroy pathogens that cause infection. </p>
<p>Although sun exposure allows the body to produce vitamin D, food sources including eggs, fish and some milks and margarine brands may be fortified with Vitamin D (meaning extra has been added).</p>
<p>Most people need just <a href="https://www.cancer.org.au/preventing-cancer/sun-protection/vitamin-d/">a few minutes outdoors</a> most days.</p>
<p>People with vitamin D deficiency may need supplements. A <a href="https://www.ncbi.nlm.nih.gov/pubmed/30675873">review of 25 studies</a> found vitamin D supplements can help protect against <a href="https://www.healthline.com/health/acute-respiratory-disease">acute respiratory infections</a>, particularly among people who are deficient.</p>
<h2>5. Iron, zinc, selenium</h2>
<p>We need iron, zinc and selenium for immune cell growth, among other functions.</p>
<p><a href="https://www.betterhealth.vic.gov.au/health/ConditionsAndTreatments/iron">Iron</a> helps kill pathogens by <a href="https://www.ncbi.nlm.nih.gov/pubmed/30336639">increasing the number of free radicals</a> that can destroy them. It also regulates enzyme reactions essential for immune cells to recognise and target pathogens. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/320686/original/file-20200316-18079-my91st.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Whole grain foods contain a variety of important nutrients.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p><a href="https://www.healthdirect.gov.au/zinc">Zinc</a> helps maintain the integrity of the skin and mucous membranes. Zinc and <a href="https://en.wikipedia.org/wiki/Selenium">selenium</a> also act as an antioxidant, helping mop up some of the damage caused by oxidative stress. </p>
<p>Iron is found in meat, chicken and fish. Vegetarian sources include legumes, whole grains and iron-fortified breakfast cereals. </p>
<p>Zinc is found in oysters and other seafood, meat, chicken, dried beans and nuts. </p>
<p>Nuts (especially Brazil nuts), meat, cereals and mushrooms are good food sources of selenium.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-should-i-take-vitamin-c-or-other-supplements-for-my-cold-98309">Health Check: should I take vitamin C or other supplements for my cold?</a>
</strong>
</em>
</p>
<hr>
<h2>Putting it all together</h2>
<p>It’s true some supermarkets are out of certain products at the moment. But as much as possible, focus on eating a variety of foods <a href="https://www.eatforhealth.gov.au/guidelines/australian-guide-healthy-eating">within each of the basic food groups</a> to <a href="https://www.ncbi.nlm.nih.gov/pubmed/25625814">boost your intake</a> of vitamins and minerals.</p>
<p>While vitamin and mineral supplements are <a href="https://theconversation.com/mondays-medical-myth-take-a-vitamin-a-day-for-better-health-8482">not recommended for the general population</a>, there are some exceptions. </p>
<p>Pregnant women, some people with chronic health conditions, and people with conditions that mean they can’t eat properly or are on very restrictive diets, may need specific supplements. Talk to your doctor, Accredited Practising Dietitian or pharmacist.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/social-distancing-what-it-is-and-why-its-the-best-tool-we-have-to-fight-the-coronavirus-133581">Social distancing: What it is and why it's the best tool we have to fight the coronavirus</a>
</strong>
</em>
</p>
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<p>And beyond diet, there are other measures you can take to stay as healthy as possible in the face of coronavirus.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/30789425">Stop smoking</a> to improve your lung’s ability to fight infection, perform <a href="https://www.ncbi.nlm.nih.gov/pubmed/32139352">moderate intensity exercise</a> like brisk walking, <a href="https://www.ncbi.nlm.nih.gov/pubmed/31941836">get enough sleep</a>, practise social distancing and wash your hands with soap regularly.</p><img src="https://counter.theconversation.com/content/133356/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clare Collins is affiliated with the Priority Research Centre for Physical Activity and Nutrition, the University of Newcastle, NSW. She is an NHMRC Senior Research and Gladys M Brawn Research Fellow. She has received research grants from NHMRC, ARC, Hunter Medical Research Institute, Meat and Livestock Australia, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation, Rijk Zwaan Australia and Greater Charitable Foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers, the Sax Institute and the ABC. She was a team member conducting systematic reviews to inform the Australian Dietary Guidelines update and the Heart Foundation evidence reviews on meat and dietary patterns.</span></em></p>The food we eat influences our bodies’ immune responses to infection. So focusing on nutrition is one thing we can do to help protect ourselves in the face of the coronavirus threat.Clare Collins, Professor in Nutrition and Dietetics, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1144212019-04-09T22:14:00Z2019-04-09T22:14:00ZImmigrant children’s health declines rapidly after arrival in Canada<figure><img src="https://images.theconversation.com/files/267641/original/file-20190404-123400-v5t5rj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Syrian refugee family Mohammad Al Mnajer and wife Fouzia Al Hashish sit with their three daughters Judy, second left, Jaidaa, far right, and Baylasan as they eat their after school snack at their home in Mississauga, Ont., in December 2018. </span> <span class="attribution"><span class="source">THE CANADIAN PRESS/Frank Gunn</span></span></figcaption></figure><p>A healthy, happy future, free from poverty: This is the aspiration of many new immigrants and refugees to Canada and the United States. Leaving harsh conditions and food scarcity behind, they embrace the safety and relative affluence that North America offers.</p>
<p>Few would have imagined that migration would damage their family’s well-being and lead to rapid health decline.</p>
<p>Yet research studies over the past 15 years have found that immigrants arrive in better health than Canadians — with a lower incidence of chronic diseases such as heart disease, cancer and diabetes — but <a href="http://www.statcan.gc.ca/pub/82-003-x/2011004/article/11588-eng.pdf">suffer a decline in their health as their time in Canada increases</a>.</p>
<p>This decline applies to young children too. As a professor and a postdoctoral fellow in the School of Public Health and College of Pharmacy and Nutrition at the University of Saskatchewan, we recently conducted <a href="https://doi.org/10.1139/apnm-2017-0407">the first comprehensive research project in Canada examining the health of immigrant and refugee children after their arrival in the country</a>.</p>
<p>This study, published in <em>Applied Physiology, Nutrition and Metabolism</em>, found several health concerns and nutritional deficiencies in many of these children.</p>
<h2>Higher blood pressure, unhealthy cholesterol</h2>
<p>Our study of 300 immigrant and refugee children in Saskatoon and Regina, Saskatchewan, found that these newcomer children often embrace a Western diet and sedentary lifestyle. Some parents are unaware of the dangers of overeating and the calories attached to the Western diet.</p>
<p>Overall, newcomer children were found to have borderline or elevated blood pressure— substantially higher than that of Canadian children. </p>
<p>Thirty-six per cent of the children in our study also had an inadequate intake of zinc, which is essential for growth and development. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/267672/original/file-20190404-123410-181qkl7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many immigrant parents have professional qualifications but end up working low-income jobs and struggle to buy healthy food.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Fifty-two per cent had unhealthy cholesterol levels, whereas just 35 per cent of Canadian children had similar levels. It is worth mentioning that increased stress is a known risk factor for high cholesterol.</p>
<p>Other research has found that some groups, such as South Asian immigrants — particularly women — are at a <a href="http://cmajopen.ca/content/2/3/E183.full">higher risk of developing high blood pressure the longer they reside in Canada</a>.</p>
<p>Non-European newcomers also experience <a href="http://www.statcan.gc.ca/pub/11-008-x/2005002/article/8454-eng.pdf">significant deterioration in how they rate their own health, and increase in body mass index (BMI) over time</a>, compared to people who were born in Canada. </p>
<h2>Poverty and dead-end jobs</h2>
<p>Why this decline in health? Canada offers relatively abundant food, accessible health care and <a href="http://hdr.undp.org/en/countries">a standard of living that is one of the highest in the world</a>, so the findings may appear counter-intuitive.</p>
<p>The answer lies both in the situations that immigrants and refugees have left behind, and the conditions they find when they get here.</p>
<p>Some immigrants find their pre-immigration dreams confounded by circumstance. They live in relative poverty, working dead-end jobs that fail to exploit their experience and potential. Some came to Canada as highly qualified professionals, optimistic about their prospects in a new country, but are unable to find meaningful, rewarding employment. Some who dreamed of a middle-class lifestyle struggle at the bottom of the economic pile due to language and educational barriers.</p>
<p>A diet of cheap, readily available junk food doesn’t help. </p>
<p>For many immigrant families, the stress of adjusting to life in Canada may contribute to deteriorating health. Many lose their social support network through migration. It can also be <a href="http://muse.jhu.edu/article/508579">challenging to access culturally appropriate health care</a>.</p>
<h2>Living in survival mode</h2>
<p>We spoke with numerous immigrants and health-care providers about newcomer health, diet and lifestyles. Many newcomers spoke of their aspirations to attain a good standard of living in Canada and the daily struggles they experienced to achieve this.</p>
<p>Some had become disillusioned with life in Canada because of their difficulties achieving the lifestyle they had expected, or aspired toward.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/267670/original/file-20190404-123419-1r7fh6k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Malnourished children may be overwhelmed by the abundance of food once arriving in Canada. Here, a volunteer carries a malnourished Rohingya child in the Kutupalong refugee camp near Cox’s Bazar, Bangladesh, in January 2019.</span>
<span class="attribution"><span class="source">(AP Photo/Manish Swarup)</span></span>
</figcaption>
</figure>
<p>One refugee was so disheartened by the difficulties he encountered in getting a good job and providing for his family that he wanted to be sent back.</p>
<p>“Refugees and immigrants are in survival mode, because doctors, engineers and professors are pushing shopping carts,” said one service provider, commenting on the rising number of food insecure immigrants.</p>
<p>Research has shown that health disparities among ethnic groups can be reduced when individuals are able to achieve their desired level of socio-economic attainment. As such, living on a low income for extended periods can contribute to physical and mental health problems and a turn towards unhealthy affordable food.</p>
<p>On a low income, a hamburger and fries may cost less than a salad, but will fill a rumbling stomach. </p>
<h2>An abundance of food</h2>
<p>Refugee children who have known hunger can also find it hard to control their appetite.</p>
<p>“A lot of people change the way they eat. That’s why they gain so much weight. There is an abundance of food here,” said a health-care provider in Regina.</p>
<p>“Sometimes children coming from a refugee camp with very little to eat come here and eat too much,” added an immigrant service provider. </p>
<p>Another factor is that in some cultures, plump children are considered healthy. One family told us that eating meat, once a luxury to be enjoyed once or twice a month, was now considered both desirable and essential.</p>
<p>Thirteen per cent of Canadian children aged three to 19 years are obese, compared to 10 per cent of newcomer children who have been in Canada for five years or less.</p>
<p>Understanding these newcomers’ rapid routes to obesity and deteriorating health is important if we are to prevent chronic disease in adulthood, including Type 2 diabetes and hypertension.</p>
<p>Health and social service personnel should be sensitive to these risks when devising effective and culturally sensitive health screening programs.</p><img src="https://counter.theconversation.com/content/114421/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hassan Vatanparast received research funding from Saskatchewan Research Foundation and CIHR. For the purpose of this project, we received research funding from governmental research agencies.</span></em></p><p class="fine-print"><em><span>Ginny Lane does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research shows that many immigrants are healthier than Canadians when they arrive in the country. The longer they stay, the more their health declines.Hassan Vatanparast, Professor of Public Health, University of SaskatchewanGinny Lane, Postdoctoral Fellow in Public Health, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/983112018-07-04T20:08:28Z2018-07-04T20:08:28ZScience or Snake Oil: does EASEaCOLD really help to shorten your cold?<figure><img src="https://images.theconversation.com/files/225635/original/file-20180702-116132-1jg3knb.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The evidence for herbal remedies for colds just isn't strong enough.</span> <span class="attribution"><a class="source" href="https://www.pharmacare.com.au/easeacold/">Screenshot, https://www.pharmacare.com.au/easeacold/</a></span></figcaption></figure><p>When we have a cold, which is caused by a number of different viruses, we know we should stay warm, drink plenty of fluids, and rest. In reality, many of us just solider on, sometimes with the help of an over-the-counter product from the chemist.</p>
<p>While some of these contain products such as paracetamol and phenylephrine (a decongestant), others such as EASEaCOLD contain <a href="https://www.pharmacare.com.au/product/cold-flu/">herbal remedies</a> that promise to reduce the symptoms associated with a cold or even reduce the length of a cold. </p>
<p>But is there any evidence these herbal preparations actually work?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/science-or-snake-oil-will-horseradish-and-garlic-really-ease-a-cold-87602">Science or Snake Oil: will horseradish and garlic really ease a cold?</a>
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</em>
</p>
<hr>
<h2>Echinacea</h2>
<p>Echinacea has been purported to relieve sore throats and coughs, but <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3928210/">scientific evidence to support its use</a> to treat a cold is weak. One difficulty in comparing studies is that different species, different parts of the plant, and different extraction methods are used in different studies.</p>
<p>There is <a href="https://www.ncbi.nlm.nih.gov/pubmed/25668266">some evidence</a> echinacea may reduce the length of a cold, if taken from the onset of symptoms, but the effect is not statistically significant, with people feeling better half to one day sooner than people taking a placebo.</p>
<p>In the EASEaCOLD preparation, it’s unclear what species of echinacea plant is used, what part of the plant, or how it’s obtained, so it’s difficult to determine how useful it is in treating a cold.</p>
<h2>Zinc</h2>
<p>Zinc has important immune functions, and is used as an immune-boosting supplement in situations where <a href="https://www.ncbi.nlm.nih.gov/pubmed/25825289">zinc deficiency</a> is likely. </p>
<p>There are studies that show <a href="https://www.ncbi.nlm.nih.gov/pubmed/28515951">zinc lozenges</a>, taken frequently throughout a cold, can shorten the duration, although how big an effect this would actually have is difficult to ascertain from the studies.</p>
<h2>Garlic</h2>
<p>Garlic is another popular anti-cold measure, but there is a lack of reliable studies to show it’s effective. </p>
<p>A single <a href="https://www.ncbi.nlm.nih.gov/pubmed/11697022">study</a> showed garlic supplements could reduce the chances of getting a cold, but <a href="https://www.ncbi.nlm.nih.gov/pubmed/25386977">authors of a review</a> concluded this one study wasn’t enough evidence (especially when you consider it was authored by the Garlic Centre in the UK).</p>
<p>And it doesn’t appear to significantly reduce the symptoms of a cold, nor its length, once you’ve developed a cold.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225639/original/file-20180702-116117-1yonw28.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A review found one study where garlic decreased the chances of getting a cold. But the authors said this wasn’t enough to prove effectiveness.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/science-or-snake-oil-is-manuka-honey-really-a-superfood-for-treating-colds-allergies-and-infections-78400">Science or Snake Oil: is manuka honey really a 'superfood' for treating colds, allergies and infections?</a>
</strong>
</em>
</p>
<hr>
<h2>Vitamin C</h2>
<p>Vitamin C is a common supplement believed to help treat or prevent a cold. </p>
<p>A <a href="https://www.ncbi.nlm.nih.gov/pubmed/23440782">large review</a> of the literature found while taking Vitamin C long-term may help reduce the severity of a cold in certain populations (such as those under long-term physical stress), taking Vitamin C once a cold has developed has no effect on duration or severity.</p>
<h2>White willow</h2>
<p>EASEaCOLD also contains white willow, apparently in order to reduce fever and pain associated with colds. White willow, or the bark of a willow tree, is converted in the body to a substance similar to <a href="https://www.ncbi.nlm.nih.gov/pubmed/28106908">aspirin</a>. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/12873261">Aspirin</a> is helpful at relieving pain associated with the common cold, but it doesn’t really help with <a href="https://www.ncbi.nlm.nih.gov/pubmed/26387658">respiratory symptoms</a>.</p>
<p>There is no evidence white willow helps in the treatment of a cold. A standard dose of aspirin will provide temporary relief from a sore throat.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225640/original/file-20180702-116135-i40qly.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There’s no evidence white willow bark provides cold relief.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Black elderberry</h2>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/28198157">Black elderberry</a> is a commonly used treatment for viral infections, but there’s not a lot of research about its effectiveness in cold treatment. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225641/original/file-20180702-116126-h33r9i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There’s not enough evidence to decide whether elderberry is effective.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>A <a href="https://www.ncbi.nlm.nih.gov/pubmed/27023596">study</a> that involved people taking black elderberry ten days before overseas air travel found it made no difference as to whether a person caught a cold or not. Although the authors suggest a difference in cold duration and severity, the evidence here seems weak.</p>
<p>They compared the collective duration of colds for all the study participants, rather than the average length of a cold. Given the group sizes were not equal, this isn’t a reliable finding. More research with an increased number of participants is needed to determine if severity and duration are really improved.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/science-or-snake-oil-do-men-need-sperm-health-supplements-84379">Science or Snake Oil: do men need sperm health supplements?</a>
</strong>
</em>
</p>
<hr>
<h2>Chamomile</h2>
<p>Chamomile is included in the night-time formulation, presumably to improve sleep. Unfortunately, there is <a href="https://www.ncbi.nlm.nih.gov/pubmed/25644982">no evidence</a> chamomile helps you get to sleep sooner, sleep longer, or wake less often.</p>
<h2>The verdict</h2>
<p>Studying herbal preparations is problematic because the parts of a plant, its species, and the methods for obtaining the desired compound all may influence the effect of the compound. So comparing different studies can be challenging, and companies will struggle to demonstrate the effectiveness of their products.</p>
<p>It may be that some of these supplements taken together have an effect, even if they don’t have any effect on their own. But there have been no well-designed trials to assess the efficacy of these supplements. Products with <a href="https://www.ncbi.nlm.nih.gov/pubmed/24261438">paracetamol and phenylephrine</a> have more evidence they provide symptom relief than herbal supplements.</p>
<p>There is very little evidence the herbal and vitamin supplements in EASEaCOLD Cold and Flu, Day and Night help to treat the common cold, or the symptoms associated with a cold. Some, such as echinacea and garlic, may help to prevent a cold, or reduce its length or severity if taken prior to the cold’s onset. But <a href="https://www.ncbi.nlm.nih.gov/pubmed/25614158">good hygiene</a> may be more effective (and cheaper!) in preventing a cold.</p><img src="https://counter.theconversation.com/content/98311/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kim Murphy does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We asked an immunologist to assess the evidence for a popular cold and flu herbal remedy. She concluded there isn’t enough evidence to support its use.Kim Murphy, Immunology researcher, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/709702017-01-09T12:12:27Z2017-01-09T12:12:27ZWhat happens to your gut if you eat the $2,000 New York pizza topped with gold?<figure><img src="https://images.theconversation.com/files/152114/original/image-20170109-23468-xjv5yg.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cock and bullion: the $2,000 pizza. </span> <span class="attribution"><span class="source">Industry Kitchen</span></span></figcaption></figure><p>A restaurant in the New York financial district <a href="http://www.maxim.com/entertainment/2000-dollar-gold-pizza-2017-1">is offering customers a pizza</a> priced at US$2,000 (£1,623). It is topped with caviar, stilton cheese and gold leaf, with each bite costing around US$50. </p>
<p>New York is usually the kind of place that sets trends, but pizzerias elsewhere have actually been making pizzas sparkle for a while. A takeaway pizza chain in London <a href="http://www.mirror.co.uk/news/weird-news/worlds-most-expensive-pizza-500-7395670">started offering</a> £500 pizzas a year ago, this time with added lobster, caviar and truffle oil; while a Glasgow restaurant <a href="http://www.dailyrecord.co.uk/business/business-news/savour-pleasures-classic-italian-food-3081571">attracted attention</a> by selling a gold leaf pizza on eBay. </p>
<p>Gold on food goes back a good deal further than that, however. The renowned Italian chef, Gualtiero Marchesi, <a href="https://www.finedininglovers.com/blog/food-drinks/marchesi-milanese-gold-risotto/">has been</a> topping his signature dish, risotto alla milanese, with a single leaf of gold for decades. And that too is recent when you reflect that the kitchens of the wealthy were <a href="https://books.google.co.uk/books?id=HectxYEZg0oC&pg=PA110&lpg=PA110&dq=%22gold+leaf%22+food+medieval&source=bl&ots=mB3ymFLK31&sig=YBWFZOikAbP__r2nmgGwbsWTKSc&hl=en&sa=X&ved=0ahUKEwj4lJ-i863RAhXCORoKHbaRDggQ6AEIUjAO#v=onepage&q=%22gold%20leaf%22%20food%20medieval&f=false">sprinkling</a> the precious metal on feast cuisine <a href="https://cornucaupia.com/deiaurum/wiki-gold-and-silver-leaf-edible-html/">during</a> medieval times. </p>
<p>There is a medieval liqueur still consumed today with gold flakes in it known as <a href="http://www.local-life.com/gdansk/articles/goldwasser">Goldwasser</a>. Gold leaf is <a href="http://www.ediblegold.co.uk">also used</a> on chocolates and even has an E number (<a href="http://www.ukfoodguide.net/e175.htm">E175</a>). Whatever else has changed over the years, swallowing gold has always been considered the highest form of decadence. But what happens when we put gold into the body? And are there any other metals we’d be better off shaving on to pizzas instead?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=460&fit=crop&dpr=1 600w, https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=460&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=460&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=578&fit=crop&dpr=1 754w, https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=578&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/152017/original/image-20170106-18662-hzyla2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=578&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Better than chicken nuggets.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/pic-340054991/stock-photo-superhero-pizza-man.html?src=ZSpgSF_i8bp_bygQHn3pYw-1-49">Luis Molinero</a></span>
</figcaption>
</figure>
<h2>Eat your carats</h2>
<p>Gold is an inert metal and is therefore not degraded by the acid in our stomachs. It will travel the length of the intestinal system unchanged, passing out in your poo. Depending on the sewage treatment system, it will eventually be returned to the land or washed out to sea ready to be recycled again. It casts panning for gold in an entirely new light. </p>
<p>Other metals are generally not used for ostentatious displays of edible wealth, but one exception is silver. Silver can be beaten into a leaf similar to gold and is also approved for use as an additive (<a href="http://www.ukfoodguide.net/e174.htm">E174</a>) – so long as it is pure and in its non-ionic form, which is the one that can’t be absorbed by the body. </p>
<p>Even then it is easier to add other metals to silver than gold, so there is still the risk it can be contaminated with the likes of aluminium. This can reduce the body’s ability to absorb essential minerals such as zinc, calcium and iron (aluminium is not essential). This will cause deficiency symptoms as diverse as soft bones (calcium), tiredness (iron) and lack of smell (zinc). </p>
<p>You might think these minerals might therefore be just the thing for a pizza, so long as they are in the ionic form that the body needs. We tend not to notice them in our diet but they are ubiquitous in grains, fruit and vegetables as they are essential for plant growth, too. Meat and dairy products are particularly rich sources and we have a very efficient system of absorbing the minerals they contain. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=626&fit=crop&dpr=1 600w, https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=626&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=626&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=787&fit=crop&dpr=1 754w, https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=787&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/152016/original/image-20170106-18641-1v1lceu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=787&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Chewy sandwich filling.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/pic-466277147/stock-photo-iron-nails-on-a-wooden-yellow-backgroundselective-focusvintage-tone.html?src=5bMDe08D-GqUYB0m8CN9YA-1-44">mansong suttakam</a></span>
</figcaption>
</figure>
<p>One reason we don’t see minerals grated on our foods, of course, is that they don’t give the same bling value. But they will also react with the acid in our stomachs and get absorbed, since they are not inert. Excessive amounts of minerals in the body can be toxic, since they get laid down in soft tissues such as the brain and kidneys. This causes severe pain and eventually death. </p>
<p>In normal circumstances the body avoids such horrors by only absorbing a percentage of the minerals in the foods we eat. But if you flood the system with a mineral by taking large quantities, it can cause an excessive intake. As well as the toxicity risk, excessive intake of one essential mineral can make the body struggle to properly absorb other essential minerals – the same risk as when you ingest non-essential minerals like aluminium. </p>
<p>The bottom line is about balance, as with most of nutrition. Since there’s plenty of these minerals in the foods we eat, there’s absolutely no need and much potential harm to be had from adding any extra to our meals – or from taking supplements we don’t need. </p>
<p>Better to stick to gold, which does nothing good or bad for health except perhaps a feeling of satisfaction – or regret if you see it twinkling as it disappears down the drain. And if you’ve more money than sense and you’re still hungry for more after that gold pizza, you could always ask your willing chef to throw in a few diamonds next time. They’re inert, too, albeit a little crunchy.</p><img src="https://counter.theconversation.com/content/70970/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marie-Ann Ha does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>On sale in New York for US$2,000. Don’t all rush at once.Marie-Ann Ha, Senior Lecturer in Nutrition, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/489402015-10-19T03:37:58Z2015-10-19T03:37:58ZExplainer: a new nanochip that will detect bacterial infections in 15 minutes<figure><img src="https://images.theconversation.com/files/98672/original/image-20151016-25138-1rphveg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nanotechnology that can detect illnesses will become available next year. </span> <span class="attribution"><span class="source">shutterstock</span></span></figcaption></figure><p>A new <a href="http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=1723">device</a> – a <a href="http://encyclopedia2.thefreedictionary.com/Biological+Sensors">biological sensor</a> inside a nanochip – that can detect bacterial infections in ten to 15 minutes will become available in 2016. </p>
<p>Devised by a team of scientists from South Africa’s Stellenbosch University, the device is currently being patented. The <a href="http://www.tia.org.za/about-us">Technology Innovation Agency</a> has funded a prototype in preparation for commercialisation by April 2016.</p>
<p>Pathogenic organisms infect about <a href="https://books.google.co.za/books?id=tWWA_3s1lwcC&pg=PA183&lpg=PA183&dq=Pathogenic+organisms+infect+about+%5B250+million&source=bl&ots=x52cwqG1fq&sig=LwZPFhyv7eie9bR-l1czw9pRuf4&hl=en&sa=X&redir_esc=y#v=onepage&q=Pathogenic%20organisms%20infect%20about%20%5B250%20million&f=false">250 million</a> people a year. At least 8%, around 20 million people, die. Early detection of infections can prevent many deaths.</p>
<p>Since the nanochip was announced as a project of the university in September 2014, progress has been made in developing additional sensing mechanisms, enhancing its capabilities.</p>
<h2>How the nanochip was born</h2>
<p>The nanochip for early detection of infection came after a chance meeting between the author and microbiologist <a href="http://www.innovus.co.za/pages/posts/meet-our-researcher-professor-leon-dicks-microbiology-76.php">Leon Dicks</a>, an expert in the field of superconductors and nanoelectrical devices. </p>
<p>While discussing individual current research, we agreed to work to find a way of detecting infections early and accurately.</p>
<p>The basis for our research was <a href="http://www.explainthatstuff.com/piezoelectricity.html">piezoelectricity</a>, which is how crystals convert mechanical energy into electricity or vice-versa. </p>
<p>The sensor that was developed for this purpose comprises a nanochip stacked with zinc oxide molecules on top of each other to create millions of nanowires.</p>
<p>Piezoelelectric energy plays a key role in the identification process. When certain materials, such as zinc oxide wires, are squeezed or pressed they generate an electric charge in response to applied mechanical stress. The slightest disturbance in the structure of the nanowires on the chip leads to piezoelectric energy. This is then converted to electrical energy and amplified to produce a voltage reading.</p>
<p>Microorganisms, such as bacteria, are known as flagellated micro-organisms. Flagella are almost like little tails that are fixed to the organism. Vigorous movement of the flagella is used to propel the organisms at quite a high speed. These movements disturb the nanowires to generate an electronic signal due to the piezoelectric effect.</p>
<h2>Biological flavour</h2>
<p>The nanochip will use a flexible substrate that would generate electricity by movement of a person’s body, thereby, for example, charging the battery of an electronic device, such as a <a href="http://www.medicinenet.com/pacemaker/page3.htm#what_is_a_pacemaker">pacemaker</a>.</p>
<p>To be able to use the nanochip for infection detection, a biological flavour was added to the sensor and application by adding a lure that would attract specific bacteria. A <a href="http://benthamscience.com/journals/current-nanoscience/volume/10/issue/6/page/827/">silicon chip</a>, measuring 1cm², was stacked with zinc oxide molecules on top of each other to create a nanowire.</p>
<p>The concept was tested by attaching lysozyme molecules to the tip of each nanowire. Bacteria buster <a href="http://dictionary.reference.com/browse/lysozyme">lysozyme</a> was chosen for the test because it is in abundance in human saliva, tears and milk. </p>
<p>As soon as lysozyme-specific antibodies sticks to the nanowires, the zinc oxide molecules were realigned. This movement was detected by a change in the electrical output in 15 minutes. The lysozome-specific antibodies stuck to the lysozome molecules. The movement caused by this attraction and attachment process disturbed the nanowires, resulting in an electric signal being generated.</p>
<h2>What we found</h2>
<p>The investigation showed that the zinc oxide nanowires are promising piezoelectric nanoforce transducers that may be developed into biomolecular detection systems.</p>
<p>Binding of antibodies to the biosensor surface indicates a strong piezoelectric effect on the biosensing signal. The designed nanoforce biosensor showed a linear relationship with respect to voltage output and antibody concentration.</p>
<p>The <a href="http://www.sciencedirect.com/science/article/pii/S0925400514007655">results</a> showed that it is possible to detect biomolecular interactions by coupling the piezotronic and biosensing characteristics of zinc oxide nanowires.</p>
<h2>What does this mean</h2>
<p>A patient swallowing a capsule containing a nanochip for detecting infections caused by pathogens, such as E.coli, V.cholera or Salmonella will know immediately the cause of their illness. </p>
<p>The production of antibodies is the natural mechanism for humans and animals to fight bacterial infections. Antibodies are specific to pathogens and by choosing the specific antibodies to attach to the piezoelectric sensor, it becomes possible to detect the specific pathogen that is tested for. </p>
<p>The possibilities of utilising this concept for the detection of different infections or the presence of different types of bacteria are thus legion.</p>
<p>Using an antigen-specific nanochip could also provide an excellent platform for testing water quality in remote rural areas.</p>
<p>Testing for certain bacterial infections does not necessarily have to be done inside the patient’s body. A drop of blood or a patient’s sputum could be tested for diseases, such as tuberculosis, on a handheld nanochip testing station outside the body.</p>
<p>Furthermore, the nanochip biological sensor method could play an important role in the detection and control of post-operative infection. Surgeons could implant a nanochip during open heart or orthopaedic surgery. By doing this they are mindful of infections where early detection and treatment is key.</p>
<h2>Benefits</h2>
<p>The use of piezoelectric energy is not the only possible vehicle for detection of disease. The sensor also uses the piezoelectric effect to detect the pathogens by attaching antibodies to the sensor. The sensor attracts the specific pathogens.</p>
<p>Other mechanisms can be used to detect the presence of pathogens in a patient’s body. These mechanisms also use antibodies as bait.</p>
<p>The method of detection can be optical, when attracted pathogens interfere with the transmission of light through an optical fibre coated with a scaffolding structure with antibodies attached to it. It may be resistive when the pathogens alter the resistance of a sensing structure. It is capacitive when the pathogens change the dielectric constant of the sensing structure.</p>
<p>It may be resistive when the pathogens alter the resistance of a sensing structure. It is capacitive when the pathogens change the dielectric constant of the sensing structure.</p>
<p>We look at different sensing structures, obviously with the antibodies attached, to use different sensing techniques. Other methods, including optical, resistive and capacitive sensing techniques, are currently being looked at.</p>
<p>Apart from the lives saved by early detection and treatment of infections, the nanochip biological sensor approach could become a less expensive diagnostic method if manufactured on a large scale. Costs would be reduced.</p><img src="https://counter.theconversation.com/content/48940/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Willie Perold receives funding from the National Research Foundation (NRF) and the Technology Innovation Agency (TIA). </span></em></p>A novel approach to detect bacterial infections in 10-15 minutes is expected to become commercially available next year.Willie Perold, Vice Dean (Research), Faculty of Engineering, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/288892014-08-25T04:39:50Z2014-08-25T04:39:50ZHealth Check: five supplements that may help with depression<figure><img src="https://images.theconversation.com/files/57115/original/qrf8vz9w-1408669899.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">While there's evidence for the efficacy of some supplements as potential treatments for depression, there's none for others, and some have been found to be ineffective.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/mihalorel/4986496932">Михал Орела/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Over <a href="http://www.anao.gov.au/Publications/Audit-Reports/2011-2012/Therapeutic-Goods-Regulation-Complementary-Medicines/Audit-brochure">two-thirds of Australians</a> are thought to use complementary medicines ranging from vitamin and mineral supplements to herbal to aromatherapy and homeopathic products. Mental health concerns are one of the reasons why people use supplements, but are they really useful?</p>
<p>While there’s evidence for the efficacy of some supplements as potential treatments for depression, there’s none for others, and some have been found to be ineffective. But effectiveness is not the only concern – the <a href="https://www.mja.com.au/journal/2012/196/5/current-challenges-appraising-complementary-medicine-evidence">quality and cost</a> of unregulated products can also be problematic. </p>
<p>And then there’s the issue of discerning between bone fide evidence from double-blind randomised controlled trials and slick company marketing campaigns. </p>
<p>Of the supplements that have been studied for improving general mood or treating clinical depression, omega-3 fatty acids, St John’s wort, S-adenosyl-methionine (SAMe), N-acetyl cysteine (NAC) and zinc are the most researched and commonly used.</p>
<h2>Omega-3 fatty acids</h2>
<p>There are three types of omega-3 fatty involved in human physiology. They are important for normal metabolism.</p>
<p><a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(05)79168-6/fulltext">Epidemiological studies</a> show that low dietary intake of omega-3 oils from fish may be related to increased risk of depressive symptoms. <a href="http://www.ncbi.nlm.nih.gov/pubmed/21931319">A review</a> of dozens of clinical trials on major depression that assessed the efficacy of these fatty acids alone or in combination with antidepressants, supported their use in depression.</p>
<p>And <a href="http://www.ncbi.nlm.nih.gov/pubmed/21903025">a meta-analysis</a> combining the results of five similar studies found a significant effect in favour of omega-3 fatty acids for reducing bipolar depression.</p>
<h2>SAMe</h2>
<p><a href="http://umm.edu/health/medical/altmed/supplement/sadenosylmethionine#ixzz3B4p7bcXy">S-adenosyl-methionine</a> (SAMe) is a naturally occurring compound found in almost every tissue and fluid in the body that’s involved in processes, such as producing and breaking down brain chemicals including serotonin, melatonin, and dopamine.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/19909689">Double-blind studies</a> show injected and oral preparations (between 800 milligrams to 1600 milligrams) of SAMe are as effective as antidepressants, and tend to produce relatively fewer adverse effects. SAMe also improves the <a href="http://www.ncbi.nlm.nih.gov/pubmed/20595412">response to antidepressant medication</a>.</p>
<p>It’s a little expensive but SAMe appears well tolerated with only mild adverse effects such as headaches, restlessness, insomnia and gastrointestinal upsets.</p>
<h2>St John’s wort</h2>
<p>St John’s wort (<em>Hypericum perforatum</em>) is a flowering plant that has a long history of medicinal use. It’s been studied for treating depression in over 40 clinical trials of varying methodological quality. </p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/18843608">A 2008 Cochrane review</a> of 29 trials involving 5,489 patients analysed comparisons of St John’s wort with placebo or dummy pills and with antidepressants. It showed people were significantly more likely to respond to St John’s wort than to placebo. In the same analysis, St John’s wort had an equivalent effect to antidepressants. </p>
<p>Because of the risk of drug interactions, people taking other medicines should only use St John’s wort with low amounts of the plant chemical hyperforin, which has effects on drug levels in the body (see an appropriate health professional for advice on this). </p>
<p>The supplement should not be taken with antidepressants as it can cause serotonin syndrome, a potentially fatal nervous system event.</p>
<h2>NAC</h2>
<p>N-acetyl cysteine (NAC) is an amino acid with strong antioxidant properties that has a history of use in the management of paracetamol overdose. It’s been found to significantly reduce depression in bipolar disorder. </p>
<p>In a <a href="http://www.ncbi.nlm.nih.gov/pubmed/18534556">24-week placebo-controlled trial</a> of 75 people with bipolar disorder, one gram of NAC twice a day significantly reduced depression. The supplement appears to have no significant adverse reactions but is currently only available from compounding pharmacies or from overseas.</p>
<h2>Zinc</h2>
<p>Zinc is a mineral found in some food, and there’s emerging evidence that it improves depressed mood. </p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/21798601">A 2012 review</a> of randomised controlled trials found two 12-week trials, with sample sizes of 60 and 20 people, showed zinc as an adjunct to antidepressants significantly lowered depression. </p>
<p>Zinc can be safely prescribed in doses up to 30 milligrams a day, although it should have amino acid another aid to improve absorption. While zinc is a fairly safe supplement, it may cause nausea on an empty stomach.</p>
<h2>A cautionary note</h2>
<p>This is a very basic overview of the evidence for these five supplements, and people considering their use should get health professional advice before starting to take them. </p>
<p>The studies mentioned here tend to support that “add-on” prescription of a range of nutrients, such as omega-3 fatty acids, SAMe, folic acid, N-acetyl cysteine and zinc, with various medicines, such as antidepressants, have a beneficial effect in improving treatment beyond that of placebo. But again, be sure to seek medical advice before combining any supplements with medications.</p>
<p>Clinical trials have <a href="http://www.australianprescriber.com/magazine/37/3/90/3">demonstrated little or no effect</a> for valerian in insomnia, St John’s wort in anxiety disorders or attention deficit hyperactivity disorder, n-acetyl cysteine or docosahexaenoic acid (DHA) fatty acids for unipolar depression, and omega-3 for bipolar mania, among others.</p>
<p>The <a href="http://www.ncbi.nlm.nih.gov/pubmed/22633580">majority of Australians</a>, especially women, already take a range of nutrient and herbal-based supplements for a number of mental health problems. But, consumers should be mindful of the evidence for their effectiveness and differences between the quality and standardisation of supplements, as well as potential drug interactions. </p>
<p><a href="http://www.nutrientsdepressionstudy.com">Click here for information</a> on participating in a clinical trial, running in Brisbane and Melbourne, assessing the use of nutraceuticals for people who are depressed.</p><img src="https://counter.theconversation.com/content/28889/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>
Dr Sarris is involved in academic research of natural products in the treatment of psychiatric disorders. This publication is not supported by any direct funding and no potential financial benefit is expected as a result of this publication. Dr Sarris has received honoraria, research support, royalties, or consultancy or travel grant funding from Integria Health, Blackmores, Bioceuticals, South Pacific Elixers, Pepsico, HealthEd, Soho-Flordis, Pfizer, Elsevier, the Society for Medicinal Plant and Natural Product Research, CR Roper Fellowship, an the National Health and Medical Research Council.
</span></em></p>Over two-thirds of Australians are thought to use complementary medicines ranging from vitamin and mineral supplements to herbal to aromatherapy and homeopathic products. Mental health concerns are one…Jerome Sarris, Senior Research Fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/253232014-05-05T04:32:46Z2014-05-05T04:32:46ZHealth Check: can you treat the common cold?<figure><img src="https://images.theconversation.com/files/47370/original/y7zkxz99-1398838645.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Unfortunately, nothing really works – or works that well – to prevent or treat colds.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/spencerjj/4255336370">Jacob Spencer</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>With symptoms including a runny nose, sore throat, sneezing, cough, headaches and fever, the <a href="http://www.cdc.gov/features/rhinoviruses/">common cold</a> can leave you feeling rotten for up to two weeks. </p>
<p>As the name suggests, they’re annoyingly common, with the average adult likely to get <a href="http://www.uptodate.com/contents/the-common-cold-in-adults-beyond-the-basics">two or three colds a year</a>, while children average ten. </p>
<p>Common colds are caused by <a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Colds_explained">more than 200 different viruses</a> and tend to be <a href="https://theconversation.com/health-check-when-is-the-flu-really-a-cold-25150">milder</a> than the flu. But while the <a href="https://theconversation.com/explainer-the-2014-flu-vaccine-24294">influenza vaccination</a> can prevent against the most common circulating strains of the flu, there’s no equivalent for the common cold. </p>
<p>So, can you prevent the common cold? Or treat it once you have it? Let’s put four popular therapies to the test: echinacea, garlic, vitamin C and zinc. </p>
<h2>Echinacea</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/47460/original/xvvwnywp-1398900311.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The evidence for using echinacea to treat or prevent a cold is murky.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/chris9002/6004751079">Gib3102/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Echinacea is a group of flowering plants common in North America, and was a traditional Native American medicine. These days you can buy the product in capsules, tablets or drops. </p>
<p>Around <a href="http://dx.doi.org/10.1046/j.1038-5282.2001.00351.x">one in 20 Australians take echinacea</a>, in the hope that extracts will stimulate immunity and kill off any bugs encountered.</p>
<p>In terms of prevention, taking echinacea products daily to avoid the common cold <em>may</em> slightly reduce the risk of getting a cold, but the evidence is <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000530.pub3/full">rather murky</a>. If we <a href="http://www.cochrane-net.org/openlearning/html/mod12-2.htm">pool the results</a> from studies that compared Echinacea to placebo treatment, people who took Echinacea seemed to get fewer colds. But there is <a href="http://handbook.cochrane.org/chapter_9/9_5_1_what_is_heterogeneity.htm">major inconsistency</a> between the individual studies, so combining them together this way isn’t very valid.</p>
<p>In terms of treatment, there is no convincing clinical evidence that taking echinacea products at the onset of symptoms can cure a cold or reduce the duration of illness. </p>
<p>However, it’s difficult to come to any clear conclusions or recommendations about echinacea’s effect on the common cold because the preparations studied have varied, with different species, parts of the plant, preparation method and dosage. </p>
<p>Echinacea products are not without side effects, such as <a href="http://www.mhra.gov.uk/Safetyinformation/Generalsafetyinformationandadvice/Herbalmedicines/Herbalsafetyupdates/Allherbalsafetyupdates/CON180630">allergic reactions</a> in children which, though uncommon, can be severe.</p>
<h2>Garlic</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/47461/original/24drqwqz-1398900442.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The lack of quality evidence precludes recommending garlic supplements for the common cold.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/christing/150532387/">Christine Vaufrey/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Garlic has been promoted as a natural preventative against the common cold, taken in commercial products or eaten raw. </p>
<p>It too is seen to have antiviral and antimicrobial properties, and manufacturers claim it boosts the immune system. The mechanisms behind these actions are unclear but the chemical <a href="http://en.wikipedia.org/wiki/Allicin">allicin</a>, which is responsible for the aroma of fresh garlic, may be the active agent. </p>
<p>There is a dearth of quality scientific evidence about the effect of garlic on colds. The recent <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006206.pub3/full">Cochrane systematic review</a> which set out to answer this question could find only one study suitable for analysis. </p>
<p>Participants who took a garlic capsule (with a standardised dose of allicin powder) daily for three months reported fewer days of illness from colds than those who took a placebo. But they were more likely to suffer from side effects such as skin rash, and body odour.</p>
<p>These results may appear promising but need to be approached cautiously until replicated. It’s always possible there are biases in a single study – for instance, the study author appears to sell <a href="http://www.garlic.mistral.co.uk/">medicinal garlic products</a>. </p>
<p>The lack of quality evidence precludes a recommendation for using garlic supplements for the common cold. But, of course, people who like eating garlic should continue to do so.</p>
<h2>Vitamin C</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/47462/original/5vrfzbk4-1398900833.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">For the most part, taking vitamin C is not effective.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/oyf/3670206555">yat fai ooi/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Vitamin C is commonly found in fresh fruits and vegetables and is one of the most common supplements taken by Australians. The use of <a href="https://theconversation.com/mondays-medical-myth-vitamin-c-prevents-colds-5931">vitamin C</a> for the common cold became popular in the 1970s, following its promotion by <a href="http://en.wikipedia.org/wiki/Linus_Pauling">American chemist Linus Pauling</a> who believed it had many health benefits.</p>
<p>There is <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000980.pub4/full">good study data</a> on the effect that vitamin C has on the common cold: for the most part, it isn’t effective.</p>
<p>Taking vitamin C daily as a preventative has no effect on the likelihood of getting a cold in the general community. It might have a small effect on the severity of symptoms, and on the duration of illness (about a half day for a usual cold). </p>
<p>But taking vitamin C as treatment (taking a dose after you get a cold) does not have an effect on the duration or severity of symptoms.</p>
<p>This same data found that vitamin C can be beneficial for people undergoing heavy acute physical stress, such as marathon runners and alpine skiers. But this is an unusual and specific context and the results can’t be generalised for regular community settings.</p>
<h2>Zinc</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/47463/original/mghqnk9m-1398902066.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Zinc supplements have a number of side effects.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-171239816/stock-photo-supplementary-food-zinc-isolated-on-a-white-background.html?src=KJvA0JjxPsZlYuDLJO2pkw-1-5">ahahey2000/Shutterstock</a></span>
</figcaption>
</figure>
<p>This mineral is an essential nutrient and is found in both plant and animal sources. Foods that are <a href="http://dx.doi.org/10.5694/mjao11.11493">particularly rich</a> in zinc include oysters, sun-dried tomatoes, beef and various seeds (including pumpkin, sunflower, sesame, and pine nuts). Oral zinc is widely available in a number of different formulations.</p>
<p>Interestingly, oral zinc <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001364.pub4/full"><em>does</em> appear</a> to have a beneficial effect for the common cold, but with a number of major caveats. </p>
<p>When taken as a treatment at the onset of the cold, zinc appears to reduce the duration of a cold, but only at higher doses (more than 75 milligrams a day). Zinc might be more effective in adults than in children, and when taken as lozenges, particularly in the zinc acetate form. </p>
<p>There is little data on using zinc as a regular preventative, and you might not want to because it comes with a number of unpleasant side effects, such as nausea and bad taste.</p>
<p>It’s important to note that the results vary between studies and there is <a href="http://www.cochrane-net.org/openlearning/html/mod15-2.htm">some evidence</a> of <a href="http://dl.dropboxusercontent.com/u/21306757/funnel_plot_zinc.jpg">publication bias</a>. So it may be that the estimate of the effectiveness of zinc for the common cold is exaggerated.</p>
<p>When we step back, it isn’t really that surprising that nothing really works, or works that well for preventing or treating colds. Given how common it is, any truly effective therapy would be a massive commercial blockbuster and hardly a secret. </p>
<p><em><strong>General practice registrars Dr Samuel Cheng and Dr Catherine Lip, from the GP Unit, Fairfield Hospital, co-authored this article.</strong></em></p><img src="https://counter.theconversation.com/content/25323/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Tam is a general practitioner and consults with patients who suffer from the common cold. He otherwise does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.</span></em></p>With symptoms including a runny nose, sore throat, sneezing, cough, headaches and fever, the common cold can leave you feeling rotten for up to two weeks. As the name suggests, they’re annoyingly common…Michael Tam, General Practitioner, and Conjoint Senior Lecturer, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/45882012-01-09T02:46:57Z2012-01-09T02:46:57ZMonday’s medical myth: eating oysters makes you randy<figure><img src="https://images.theconversation.com/files/6815/original/r97s93zt-1326076934.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Oysters can still play an important role in romance, even though they aren’t an aphrodisiac.</span> <span class="attribution"><span class="source">Stephen Coles</span></span></figcaption></figure><p><strong>The stuff of romance novels or a secret tool to give you a boost in the bedroom? We start the year by examining the truth about oysters.</strong></p>
<p><em>Holly gazed around in awe. Rory had brought her to a tiny waterfront restaurant. From the table on the jetty she watched the setting sun sparkle across the bay and reflect off Rory’s chocolate brown eyes.</em> </p>
<p><em>“I hope you like oysters, Holly. I took the liberty of ordering us three dozen with samples of the chef’s special toppings. This restaurant is famous for their delicious oysters.”</em></p>
<p><em>Holly sighed. Although she had known Rory for a while, this was their first date and very romantic. “Remember, first date, home alone by midnight,” she murmured, more as a reminder to herself. But, oysters! Heavens, weren’t they supposed to be an aphrodisiac?</em></p>
<p>Does Holly withstand the oyster’s reputation for inspiring passion? Or will they make her abandon caution and leap into Rory’s embrace? </p>
<p>All will be revealed – but first a short aside.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6803/original/nrqc5ntb-1326071969.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1130&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Lee & Chantelle McArthur</span></span>
</figcaption>
</figure>
<p>Like all good myths, there’s an element of truth in the “oysters-make-you-randy” story. But a plateful of oysters for dinner will not, by themselves, lead to a night of wild passion. </p>
<p>Having said that, back in 2005, newspapers in <a href="http://www.telegraph.co.uk/news/uknews/1486054/Raw-oysters-really-are-aphrodisiacs-say-scientists-and-now-is-the-time-to-eat-them.html">the United Kingdom</a> and in <a href="http://www.smh.com.au/articles/2005/03/23/1111525227607.html">Australia</a> reported with breathless glee that scientists had finally made a connection between eating oysters and a rise in the levels of sex hormones in male and female rats due to the existence of a couple of unusual amino acids. </p>
<p>Perhaps Casanova was right to power up with oysters before his lusty bedroom activities. He went through <a href="http://www.cuanoysters.com/true/index.html">60 of the slippery molluscs</a> a day, which would have had a beneficial impact on his body’s zinc level, never mind his sex hormones.</p>
<p>Oysters are a particularly good source of zinc, an important mineral in our diet and essential for function of many of our body’s systems. A shortage of zinc can have a <a href="http://journals.lww.com/co-gastroenterology/Abstract/2009/03000/Zinc_deficiency.9.aspx">detrimental effect</a> on our reproductive systems, and the mineral is also known to help boost testosterone levels. </p>
<p>We don’t store zinc in our bodies so we have to replenish the supply regularly. Zinc from fish and meat is better absorbed by our bodies than zinc in grains. Liver has a good supply of zinc – think paté and this option becomes sexier – but oysters have a whole lot more of the mineral than <a href="http://www.mja.com.au/public/nutrition/women/wquest3.html">any red meat</a>.</p>
<p>But when did we start eating oysters? There’s evidence from middens found around the Australian coast that Aboriginal communities were eating oysters some <a href="http://www.dpcd.vic.gov.au/__data/assets/pdf_file/0011/35894/AA_13_ShellMiddens_13.06.08.pdf">12,000</a> to <a href="http://www.environment.gov.au/parks/booderee/culture-history/aboriginal-history.html">20,000</a> years ago. </p>
<p>In more recent times, <a href="http://www.jstor.org/pss/3293643">the Romans</a> considered oysters as a delicacy. Pliny wrote that the best oysters were found in river mouths where light from the sun made them sweet and plump. </p>
<p>So fond were the Romans of oysters that they even developed ways to cultivate them, creating the first oyster farms. And when they invaded Britain, the Romans discovered a plentiful supply of oysters around Britain’s coast; oysters that were shipped back to Rome live for the discerning Roman public. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6800/original/jrp8sw4q-1326071420.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The demise of oyster beds means what we eat now are farmed.</span>
<span class="attribution"><span class="source">Durundal</span></span>
</figcaption>
</figure>
<p>By the 18th century, oysters had become an easily accessible food for <a href="http://gothamcenter.org/blotter/?p=66">New York</a> and London poor. They were dredged by fishermen in barges, or picked over by hand at low tide, and sold by <a href="http://www.oldbaileyonline.org/static/London-life.jsp">street sellers</a> pushing barrows. But by the <a href="http://h2g2.com/dna/h2g2/classic/A283105">middle of the 19th century</a>, the oyster beds were gone – destroyed through indiscriminate fishing practices. </p>
<p>As availability of oysters decreased, cultivated oysters became an extravagance and were sold at a premium price. With the demise of the oyster beds went the <a href="http://www.thefishsite.com/articles/696/cracking-the-demise-of-oysters">natural filtration processes</a> that kept waters clear, an increasingly urgent problem <a href="http://www.bbc.co.uk/blogs/thereporters/richardblack/2011/02/this_week_saw_formal_scientifi.html">recognised today</a>. </p>
<p>Here in Australia, we have three main types of farmed oysters: the Sydney rock oyster and the Angasi oyster are native to Australia, while the Pacific oyster is a native of Japan. The majority of our oysters are farmed in New South Wales, Tasmania and South Australia and we enjoy them so much that <a href="http://www.oystersaustralia.org.au/">only 3% is exported</a>. </p>
<p>Oysters may not make you randy but they do contribute to a healthy diet, which is definitely a good way to maintain sexual health. And don’t forget the pure sensual pleasure of eating oysters. The slippery, salty creature cupped in its own misshapen shell, bathed in brine, topped with a splash of lemon, a shalloty vinegar reduction or a citrusy ponzu dressing – just orgasmic!</p>
<p>So if you’re taking your partner to dinner and want to set the mood, don’t abandon the oysters… or the location, the champagne and the candlelight. Oysters can still play an important role in the game of romance, even though they aren’t an aphrodisiac in a shell.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6805/original/2ggq9qbm-1326072312.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">There’s more than one food that leads to your lover’s heart.</span>
<span class="attribution"><span class="source">Premshree Pillai</span></span>
</figcaption>
</figure>
<p>And so, back to our story…</p>
<p><em>Holly woke to find Rory gone. Self-recrimination hung like a shadow in the daylight. Eating those oysters, what was she thinking?</em></p>
<p><em>“Are you awake, Holly, gorgeous girl?” Rory stood in the doorway holding a breakfast tray in his hands. “Breakfast delivered to your bedside, princess. Cafe au lait and the best pain au chocolat in the whole town.”</em></p>
<p><em>Hastily flattening her tousled hair, Holly sat up, sniffing the glorious aromas of steaming coffee and buttery croissants. She gazed hungrily at the curls of chocolate oozing from the crisp pastry.</em></p>
<p><em>“Rory … how wonderful!” grinned Holly, feeling overwhelmingly happy.</em></p>
<p><em>Rory gave Holly a wicked smile, “They say oysters are an aphrodisiac but wait til you eat the chocolate. Nothing beats chocolate for arousing passion.”</em></p><img src="https://counter.theconversation.com/content/4588/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Penny Wilson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The stuff of romance novels or a secret tool to give you a boost in the bedroom? We start the year by examining the truth about oysters. Holly gazed around in awe. Rory had brought her to a tiny waterfront…Penny Wilson, PhD Researcher, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.