tag:theconversation.com,2011:/au/topics/medical-myths-370/articlesMedical myths – The Conversation2022-12-07T13:53:51Ztag:theconversation.com,2011:article/1946892022-12-07T13:53:51Z2022-12-07T13:53:51ZMosquitoes are not repelled by vitamins and other oral supplements you might take<figure><img src="https://images.theconversation.com/files/499541/original/file-20221207-11795-5gitd3.jpg?ixlib=rb-1.1.0&rect=1077%2C565%2C4913%2C3422&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's only wishful thinking that you can ward off mosquitoes from within.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/aedes-aegypti-mosquito-close-up-a-mosquito-sucking-royalty-free-image/831023822">frank600/iStock via Getty Images Plus</a></span></figcaption></figure><p>A longstanding medical myth suggests that taking vitamin B1, also known as thiamine, can make your body repel mosquitoes.</p>
<p>A “<a href="http://doi.org/10.1001/jama.1966.03100160106030">systemic repellent</a>” that makes your whole body unappealing to biting insects certainly sounds good. Even if you correctly reject the <a href="https://doi.org/10.1186/s12936-020-03217-5">misinformation</a> questioning <a href="https://doi.org/10.4269/ajtmh.1998.59.323">safe</a> and <a href="https://doi.org/10.1056/nejm200207043470102">effective</a> <a href="https://www.epa.gov/insect-repellents/deet">repellents</a> like <a href="https://doi.org/10.1186/1756-3305-7-173">DEET</a>, oral repellents would still have the benefit that you wouldn’t need to worry about covering every inch of exposed skin or carrying containers of bug spray whenever you venture into the great outdoors.</p>
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<p>Along with thiamine, other alleged oral mosquito repellents include <a href="https://doi.org/10.1055/s-0039-3399744">brewer’s yeast</a>, which contains thiamine, and <a href="https://doi.org/10.1001/jama.285.1.39">garlic</a>, the legendary <a href="https://europepmc.org/article/med/7825135">vampire repellent</a>.
If oral repellents sound too good to be true, it’s because they are. </p>
<p><a href="https://scholar.google.com/citations?user=TSIGUnYAAAAJ&hl=en&oi=ao">As a professor of entomology</a> in Taiwan, where the mosquito-transmitted Dengue virus is endemic, I was curious what science really says about food-based repellents. After a very deep dive into the literature and reading practically every paper ever written on the subject, I compiled this knowledge into the first <a href="https://doi.org/10.1017/S0007485321001176">systematic review</a> of the subject.</p>
<p>The scientific consensus is, unequivocally, that oral repellents don’t exist. Despite <a href="https://doi.org/10.5281/zenodo.7403167">extensive searches</a>, no <a href="http://doi.org/10.1371/journal.pntd.0006247">food, supplement</a>, <a href="https://doi.org/10.4269/ajtmh.1968.17.461">medication, or condition</a> has ever been proven to make people repellent. People with vitamin B1 deficiency don’t attract more mosquitoes, either. </p>
<p>So where did the myth that mosquitoes hate vitamins come from, and why is it so hard to exterminate?</p>
<h2>Making of a myth</h2>
<p>In 1943, Minnesota pediatrician <a href="https://doi.org/10.5281/zenodo.7313319">W. Ray Shannon</a> gave 10 patients varying doses of thiamine, which had only <a href="https://doi.org/10.1159/000343109">first been synthesized</a> seven years prior. They reported back that it relieved itching and prevented further mosquito bites. In 1945, California pediatrician <a href="https://doi.org/10.5281/zenodo.7403108">Howard Eder</a> claimed 10 milligram doses could protect people from fleas. In Europe in the 1950s, physician <a href="https://doi.org/10.5281/zenodo.7403124">Dieter Müting</a> claimed that daily 200 milligram doses kept him bite-free while vacationing in Finland, and hypothesized a breakdown product of thiamine was expelled through the skin.</p>
<p>These findings drew rapid attention, and almost immediate repudiation. The U.S. Naval Medical Research Institute <a href="https://doi.org/10.1126/science.100.2590.147.a">tried to replicate Shannon’s findings, but failed</a>. By 1949, Californians using thiamine to repel fleas from dogs were reporting it as “<a href="https://doi.org/10.1001/archderm.1949.01530070124012">completely worthless</a>.” Controlled studies from <a href="https://pubmed.ncbi.nlm.nih.gov/13568728/">Switzerland</a> to <a href="https://pubmed.ncbi.nlm.nih.gov/4733214/">Liberia</a> repeatedly failed to find any effects at any dose. The first <a href="https://doi.org/10.5281/zenodo.7403142">clinical trial</a> in 1969 concluded definitively that “vitamin B1 is not a systemic mosquito repellent in man,” and <a href="https://doi.org/10.2987/8756-971X(2005)21%5B213:TVBAAH%5D2.0.CO;2">all controlled studies since</a> suggest the same for thiamine, <a href="https://pubmed.ncbi.nlm.nih.gov/6885593/">brewer’s yeast</a>, <a href="https://doi.org/10.1111/j.0269-283X.2005.00544.x">garlic</a>, and <a href="https://doi.org/10.1024/0040-5930.62.11.713">other</a> <a href="https://doi.org/10.1093/pch/19.6.326">alternatives</a>. </p>
<p>The evidence was so overwhelming that, in 1985, the <a href="https://doi.org/10.1016/B978-0-323-54696-6.00006-9">U.S. Food and Drug Administration declared</a> all oral insect repellents are “<a href="https://tile.loc.gov/storage-services/service/ll/fedreg/fr050/fr050116/fr050116.pdf#page=140">not generally recognized as safe and effective and are misbranded</a>,” making labeling supplements as repellents technically fraud.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="foods including egg, lentils, nuts and a " src="https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/499542/original/file-20221207-27-o3hgzd.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">Along with being in poultry and pork, B1 is found in many whole grains and legumes.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/products-and-ingredients-containing-vitamin-b1-and-royalty-free-image/668509672">ratmaner/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>Medical mechanisms aren’t there</h2>
<p>Scientists know much more about both mosquitoes and vitamins today than ever before.</p>
<p>Vitamin B1 <a href="https://www.ncbi.nlm.nih.gov/books/NBK482360/">does not break down in the body</a> and has <a href="https://doi.org/10.1021/bi401618y">no known effect on skin</a>. The body strongly regulates it, absorbing little ingested thiamine after the first 5 milligrams and <a href="https://doi.org/10.1177/0884533611426149">quickly excreting any excess</a> via urine, so it <a href="https://doi.org/10.1177/0885066616659429">does not build up</a>. Overdose is almost impossible.</p>
<p>As in humans, thiamine is an <a href="https://doi.org/10.1093/aesa/70.4.541">essential nutrient</a> <a href="https://doi.org/10.1093/aesa/52.1.26">for mosquitoes</a>. There is no reason they would fear it or try to avoid it. Nor is there evidence that they can smell it.</p>
<p>The best sources of thiamine are <a href="https://doi.org/10.3390/nu12092810">whole grains, beans, pork, poultry and eggs</a>. If eating a carnitas burrito won’t make you repel mosquitoes, then neither should a pill.</p>
<p>What explains the early reports, then? Along with shoddy experimental design, many used anecdotal patient reports of fewer bite symptoms as a proxy for reduced biting, which is not a good way to get an accurate picture of what’s going on.</p>
<p>Mosquito bites are followed by <a href="https://doi.org/10.1111/j.1346-8138.1989.tb01251.x">two reactions</a>: an immediate reaction that starts fast and lasts hours and a delayed reaction lasting days. The presence and intensity of these reactions depends not on the mosquito, but on your own immune system’s familiarity with that particular species’ saliva. With age and continued exposure, the body goes from no reaction, to delayed reaction only, to both, to immediate reaction only, and eventually no reaction.</p>
<p>What Shannon and others thought was repellency could have been <a href="https://doi.org/10.3109/07853899409147906">desensitization</a>: The patients were still getting bitten, they just stopped showing symptoms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman with backpack in woods sprays her arm" src="https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/499543/original/file-20221207-27-w8izk8.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">Applying a safe and effective insect repellent to your skin is a proven way to ward off mosquitoes and their bites.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/woman-applies-mosquito-spray-to-her-hands-during-royalty-free-image/1404334863">SimpleImages/Moment via Getty Images</a></span>
</figcaption>
</figure>
<h2>So, what’s the problem?</h2>
<p>Despite the scientific consensus, a 2020 survey of pharmacists in <a href="https://doi.org/10.3390/pharmacy8020094">Australia</a> found that 27% were still recommending thiamine as a repellent to patients traveling abroad: an unacceptable recommendation. Besides wasting money, people relying on vitamins as protection against mosquitoes can still get bitten, potentially putting them at risk of <a href="https://doi.org/10.1001/jama.296.18.2234">diseases</a> like <a href="https://doi.org/10.1155/2003/158926">West Nile</a> and <a href="https://doi.org/10.2310/7060.2000.00074">malaria</a>.</p>
<p>To get around the American ban and widely agreed-upon scientific consensus on oral repellents, some unscrupulous dealers are making thiamine patches or even injections. Unfortunately, while thiamine is safe if swallowed, it <a href="https://doi.org/10.1016/j.alit.2022.01.004">can</a> <a href="https://doi.org/10.1016/S0196-0644(89)80215-X">cause</a> <a href="https://doi.org/10.1016/S0091-6749(95)70111-7">severe</a> <a href="https://doi.org/10.1001/jama.1941.72820340003008a">allergic</a> <a href="https://doi.org/10.1001/archderm.1950.01530120149018">reactions</a> when taken by other routes. <a href="https://doi.org/10.1016/j.actatropica.2012.10.009">These products</a> are thus not only <a href="https://doi.org/10.1093/jisesa/iev125">worthless</a>, but also potentially dangerous.</p>
<p>Not every problem can be solved with food. Long sleeves and <a href="https://doi.org/10.7326/0003-4819-128-11-199806010-00013">bug spray</a> <a href="http://doi.org/10.1056/NEJMoa011699">containing DEET</a>, <a href="http://npic.orst.edu/ingred/picaridin.html">picaridin</a> or <a href="https://www.epa.gov/insect-repellents/skin-applied-repellent-ingredients">other proven repellents</a> are still your best defense against biting pests.</p><img src="https://counter.theconversation.com/content/194689/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matan Shelomi 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>A medical myth persists that the B vitamin thiamine is a systemic insect repellent that wards off mosquitoes when taken orally. But scientists have disproven this mistaken belief again and again.Matan Shelomi, Associate Professor of Entomology, National Taiwan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1408302020-06-23T14:40:28Z2020-06-23T14:40:28ZVampire myths originated with a real blood disorder<figure><img src="https://images.theconversation.com/files/342281/original/file-20200616-23255-h4uj5g.jpg?ixlib=rb-1.1.0&rect=52%2C46%2C3750%2C2683&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A street painting in Bucharest, Romania, depicts Bram Stoker, right, the author of Dracula, sharing a drink with Vlad the Impaler, left, the medieval Romanian ruler who inspired the book.</span> <span class="attribution"><span class="source">(AP Photos/Vadim Ghirda)</span></span></figcaption></figure><p>The concept of a vampire predates Bram Stoker’s tales of Count Dracula — probably by several centuries. But did vampires ever really exist?</p>
<p>In 1819, 80 years before the publication of <em>Dracula</em>, John Polidori, an Anglo-Italian physician, published a novel called <a href="https://www.gutenberg.org/files/6087/6087-h/6087-h.htm"><em>The Vampire</em></a>. Stoker’s novel, however, became the benchmark for our descriptions of vampires. But how and where did this concept develop? It appears that the folklore surrounding the vampire phenomenon originated in that Balkan area where Stoker located his tale of Count Dracula.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=927&fit=crop&dpr=1 600w, https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=927&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=927&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1164&fit=crop&dpr=1 754w, https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1164&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/342292/original/file-20200616-23247-1wf5585.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1164&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bram Stoker’s <em>Dracula</em> has become the benchmark vampire.</span>
<span class="attribution"><span class="source">(Penguin Random House)</span></span>
</figcaption>
</figure>
<p>Stoker <a href="https://www.irishtimes.com/news/world/europe/bram-stoker-a-hero-for-struggling-corner-of-romania-1.1850499">never travelled to Transylvania</a> or any other part of Eastern Europe. (The lands held by the fictional count would be in modern-day Romania and Hungary.) </p>
<p><a href="https://www.bramstokerestate.com">The writer was born and brought up in Dublin</a>. He was a friend to Oscar Wilde and William Gladstone. He was both a Liberal and a home-ruler — in favour of home rule for Ireland. He turned to theatre, and became business manager of the Lyceum Theatre in London. It was his friendship with Armin Vambery, a Hungarian writer, that led to his fascination with vampire folklore. He consulted Vambery in the writing of <em>Dracula</em>, whose main character was loosely fashioned on <a href="http://www.english.upenn.edu/%7Emgamer/Etexts/prince.dracula.html">Vlad the Impaler</a>, a bloodthirsty prince born in Transylvania in 1431.</p>
<h2>Medical source of the myth</h2>
<p>But where did the myth of vampires come from? Like many myths, it is based partly in fact. A <a href="https://doi.org/10.1016/s0140-6736(09)61925-5">blood disorder called porphyria</a>, which has has been with us for millennia, became prevalent among the nobility and royalty of Eastern Europe. Porphyria is an inherited blood disorder that causes the body to produce less heme — a critical component of hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the body tissues. It seems likely that this disorder is the origin of the vampire myth. In fact, porphyria is sometimes referred to as the “vampyre disease.”</p>
<p>Consider the symptoms of patients with porphyria:</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1200&fit=crop&dpr=1 600w, https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1200&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1200&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1508&fit=crop&dpr=1 754w, https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1508&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/342284/original/file-20200616-23213-1btom74.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1508&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Elements of vampire folklore correspond to symptoms of porphyria.</span>
<span class="attribution"><span class="source">(Pixabay)</span></span>
</figcaption>
</figure>
<p><strong>Sensitivity to sunlight</strong>: Extreme <a href="https://doi.org/10.1001/jamadermatol.2015.6066">sensitivity to sunlight</a>, leading to facial disfigurement, blackened skin and hair growth.</p>
<p><strong>Fangs</strong>: In addition to facial disfigurement, repeated attacks of the disease causes the gums to recede, exposing the teeth, which then look like fangs.</p>
<p><strong>Blood drinking</strong>: Because the urine of persons with porphyria is dark red, folklore surmised that they were drinking blood. In fact, some physicians had recommended that these patients drink blood to compensate for the defect in their red blood cells — but this recommendation was for animal blood. It is more likely that these patients, who only went out after dark, were judged to be looking for blood, and their fangs led to folk tales about vampires.</p>
<p><strong>Aversion to garlic</strong>: The <a href="https://doi.org/10.1353/pbm.1990.0051">sulfur content of garlic</a> could lead to an attack of porphyria, leading to very acute pain. Thus, the aversion to garlic.</p>
<p><strong>Reflections not seen in mirrors</strong>: In the mythology, a vampire is not able to look in a mirror, or cannot see its reflection. The facial disfigurement caused by porphyria becomes worse with time. Poor oxygenation leads to destruction of facial tissues, and collapse of the facial structure. Patients understandably avoided mirrors.</p>
<p><strong>Fear of the crucifix</strong>: During the Spanish Inquisition (1478-1834), 600 “vampires” were reportedly burned at the stake. Some of these accused vampires were innocent sufferers of porphyria. Porphyria patients had good reason to fear the Christian faith and Christian symbols.</p>
<p>Acute attacks of the disease are associated with considerable pain, and both mental and physical disturbance. This condition has been ascribed to the English King George III, although subsequent analysis has <a href="https://doi.org/10.7861/clinmedicine.15-2-168">shed some doubt on porphyria</a> as the cause of his “madness.”</p>
<h2>Porphyria</h2>
<p>Nowadays, with our scientific knowledge of porphyria, instead of fearing these folks, <a href="http://canadianassociationforporphyria.ca/Porphyria-Treatments">we can love and care for them</a>. Porphyria remains incurable, and treatment is mainly supportive: pain control, fluids and avoidance of drugs and chemicals that provoke acute attacks. Some success has been achieved with stem cell transplants.</p>
<p>Could Stoker have known of the existence of porphyria, and/or its link to vampire folklore? It was only in 1911, eight years before Stoker’s book appeared, that the diseases of porphyria (there are several types) <a href="https://porphyriafoundation.org/for-patients/about-porphyria/history-of-porphyria/">were classified by H. Gunther</a>. However, physician, researcher and author George Harley had described a patient with porphyria a few years earlier.</p>
<p>Through his gothic novel, Stoker surely wins the prize for the best example of myth entangled with medicine!</p>
<p><em>This story is an edited excerpt from the book</em> Of Plagues and Vampires: Believable Myths and Unbelievable Facts from Medical Practice <em>by Michael Hefferon</em>.</p><img src="https://counter.theconversation.com/content/140830/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Hefferon 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>Did vampires ever really exist? The myth is likely related to a medical condition with symptoms that may explain many elements of centuries-old vampire folklore.Michael Hefferon, Assistant Professor, Department of Pediatrics, Queen's University, OntarioLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1339112020-03-18T02:14:16Z2020-03-18T02:14:16ZCan coronavirus spread through food? Can anti-inflammatories like ibuprofen make it worse? Coronavirus claims checked by experts<figure><img src="https://images.theconversation.com/files/321194/original/file-20200318-60906-1hhcnec.jpg?ixlib=rb-1.1.0&rect=0%2C26%2C5788%2C3748&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><em>Editor’s note: Here are some of the top coronavirus and COVID-19 <a href="https://www.facebook.com/ConversationEDU/photos/a.452035984824035/3282486441778961/?type=3&theater">claims</a> our readers said they’d like to see tested against the research evidence. We asked these public health and infectious disease experts to explain.</em></p>
<hr>
<h2>1. Is herd immunity a good strategy?</h2>
<p>Herd immunity is not part of the Australian strategy for controlling the outbreak. On social media there are many people calling for stronger and faster government responses, including “shutting everything down.” There is a particular demand for school closures, which are not currently on the cards in Australia. </p>
<p>Some have claimed the Australian government has plans to rely on “herd immunity” to control the outbreak. That’s not the case. </p>
<p>The decision not to close schools is based on data from China, which show that there’s no sign of children and young people playing a role in “chains” of transmission. In addition, closing schools, without making similar arrangements for working parents, might lead to children being looked after by grandparents, who we need to protect at all costs from exposure to the virus. Also, this could have a major impact on the health workforce, many of whom have school-aged children.</p>
<p>The development of immunity is an important question for the longer term management of COVID-19, the coronavirus at the centre of the pandemic. Eventually, many people who contract the virus will become immune and this will help control its spread. This is not a part of the Australian government’s strategy, and the UK government has clarified that it is not its policy either.</p>
<p>Clinical experience suggests people with mild illness may <a href="https://www.nature.com/articles/s41591-020-0819-2">develop immunity</a> around seven to ten days after the onset of symptoms. Immunity is measured by monitoring the immune cells that fight the virus. As these cells showed up, the virus was no longer found in nasal swabs, suggesting immunity may also reduce infectiousness.</p>
<p><a href="https://theconversation.com/newsletter"><img src="https://images.theconversation.com/files/320030/original/file-20200312-116261-a6ugi0.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=90&fit=crop&dpr=2" alt="Sign up to The Conversation" width="100%"></a></p>
<h2>2. Can drinking a lot of water, gargling with warm water and salt or vinegar eliminate the virus? What about drinking lemon in hot water, or other home remedies?</h2>
<p>Myth. Many people have asked what they can do to “boost their immune system” and there’s no shortage of quacks and scam artists happy to answer that question. </p>
<p>Hot drinks with lemon and honey, <a href="https://theconversation.com/5-ways-nutrition-could-help-your-immune-system-fight-off-the-coronavirus-133356">vitamin supplements</a>, foods with garlic and ginger, apple cider vinegar, gargling with salt water… none of these things has any impact on your immune response and won’t eliminate the virus.</p>
<p>But if they make you feel calmer and healthier, they can’t hurt. (Except putting vinegar in your nose – that’s not a good time.)</p>
<p>Other myths include that the virus can’t survive above 27ºC (80.6ºF). We can tell this is wrong with a moment’s thought, since it can function in our bodies at 37.5ºC. </p>
<p>Some have claimed that drinking various beverages will help “flush out” the virus, but the virus does its work inside cells. Again, though, hot water with lemon will help you stay hydrated, so it won’t hurt.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321184/original/file-20200318-60901-wcpo4s.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>
<figcaption>
<span class="caption">Gargling with salt water won’t eliminate the virus.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>3. Do blood pressure medicines worsen the illness?</h2>
<p>Myth. Nobody should stop taking any medication unless advised to by their doctor. </p>
<p>There was recent speculation that some blood pressure medications that target a protein called ACE2 might worsen the course of infection because the virus also targets that protein. </p>
<p>In response, the European Society of Cardiologists had <a href="https://www.escardio.org/Councils/Council-on-Hypertension-(CHT)/News/position-statement-of-the-esc-council-on-hypertension-on-ace-inhibitors-and-ang">issued a strongly worded statement</a> saying there’s no evidence to support these concerns, and potential for serious harm if people stop taking their blood pressure medication.</p>
<h2>4. What about non-steroidal anti-inflammatories like ibuprofen?</h2>
<p>The World Health Organisation has <a href="https://www.sbs.com.au/news/who-warns-against-use-of-ibuprofen-for-coronavirus-symptoms">urged</a> people who suspect they have COVID-19 to take paracetamol, not ibuprofen. </p>
<p>Non-steroidal anti-inflammatories (NSAIDS) such as ibuprofen also attach to this protein. In France, some doctors noted that a number of patients who were admitted to ICU had been taking these drugs. It is not clear whether these patients had other conditions which put them at higher risk of being admitted to ICU, or if the NSAIDs were the only risk factor.</p>
<p>This is <a href="https://www.snopes.com/fact-check/covid-19-nsaids-ibuprofen/">hotly-debated</a> and we can expect to hear more about it.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/coronavirus-weekly-expert-analysis-from-the-conversation-global-network-133646">Coronavirus weekly: expert analysis from The Conversation global network</a>
</strong>
</em>
</p>
<hr>
<h2>5. Can the virus stay living on surfaces for nine days?</h2>
<p>We don’t have data on COVID-19, although research on this is likely already happening.</p>
<p>A <a href="https://linkinghub.elsevier.com/retrieve/pii/S0195670120300463">review of studies</a> looking at similar viruses like SARS and MERS found viral particles can last for some time on surfaces — potentially up to nine days. It depends on a number of factors, such as the type of material, the temperature and humidity, and perhaps even how much of the virus was deposited.</p>
<p>Alcohol-based products were found to be effective at removing virus from surfaces. Wiping down surfaces, washing your hands, and avoiding touching your face remain the best things you can do.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=445&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=445&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=445&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=560&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=560&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321186/original/file-20200318-60885-1yi07x7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=560&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wiping down surfaces is a good thing to do.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>6. Is hand sanitiser not as effective as soap and water?</h2>
<p>A <a href="https://twitter.com/PalliThordarson/status/1236549305189597189">science-y fun fact</a> has been circulating on Twitter, saying soap is better than alcohol at disrupting the lipid layer that surrounds viral particles. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321189/original/file-20200318-60879-1qdh3e7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In fact, both soap and alcohol break virus particles apart, but in different ways.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>In fact, both soap and alcohol break virus particles apart, but in different ways. Hand washing also works because it washes viral particles off our hands. </p>
<p>Whether you use alcohol or soap isn’t really important - making sure you wash your hand often and thoroughly definitely is.</p>
<h2>7. Is Australia the next Italy?</h2>
<p>Unlikely. Vivid stories have been circulating about the <a href="https://left.it/2020/03/13/covid_19-open-letter-from-italy-to-the-international-scientific-community/">heartbreaking situation</a> in parts of northern Italy. </p>
<p>However, the lack of testing in Italy makes it hard to know if their outbreak of COVID-19 will be comparable to our own. Australia introduced protective measures much earlier than Italy, including travel deferrals and quarantine for Australians exposed to the virus on cruise ships. It is vital for epidemic control to be based on the facts about our own epidemic.</p>
<p>There is no doubt the COVID-19 outbreak is going to stretch our health system to its limits — but we do not have good reason to fear it will be as bad as stories coming out of Italy.</p>
<h2>8. Does COVID-19 only kill sick people and the elderly?</h2>
<p>Nope. Based on the experience in China and Italy, experts have challenged the belief that severe illness and mortality only affect older people and people with other serious illnesses. Older people are at the highest risk of serious illness, but the risk to younger people is not zero. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321225/original/file-20200318-37441-1f4njq8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>At any rate, people in older age groups are valued and very important members of our community, and nobody sees them as expendable. We can all protect them by following prevention advice and self-isolating if we have any reason to believe we may have been exposed.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321192/original/file-20200318-60885-hhq5nu.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">The risk to young people isn’t zero.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>9. Can coronavirus spread through food?</h2>
<p>That depends on if someone coughs on your food, or shares your spoon. </p>
<p>Coronavirus spreads via <a href="https://en.wikipedia.org/wiki/Transmission_(medicine)#Droplet">droplet transmission</a>. When someone coughs or sneezes without a mask, droplets of saliva and mucus can fall within a metre or two of the sick person. Most transmission occurs when these droplets make their way into your mouth, nose, or eyes. That’s why hand hygiene and <a href="https://theoatmeal.com/comics/touch_face">avoiding touching your face</a> are so important.</p>
<p>If you are near someone with coronavirus and they cough over your food, it could potentially make you sick. Sharing cutlery or glasses with people with coronavirus could pass on the infection, as heard on <a href="https://www.abc.net.au/7.30/coronavirus-is-changing-the-way-we-live-and-work/12061306">ABC 7.30</a>. However, you are unlikely to catch anything from the avocado you pick out of a basket at Woolies as a consolation prize after missing out on toilet paper.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-are-older-people-more-at-risk-of-coronavirus-133770">Why are older people more at risk of coronavirus?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/133911/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben Harris-Roxas receives funding from NSW Health. In the past he has received funding from the National Health and Medical Research Council, the Australian Research Council, the World Health Organization, the Australian Government Department of Health, the Public Health Agency of Canada, the Heart Foundation, NPS MedicineWise, the Sax Institute and the City of Gold Coast.</span></em></p><p class="fine-print"><em><span>Daniel Reeders, Kathryn Snow, and Trent Yarwood do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There’s no shortage of myths, scams and spurious claims circulating about coronavirus.Trent Yarwood, Infectious Diseases Physician, Senior Lecturer, James Cook University and, The University of QueenslandBen Harris-Roxas, Associate Professor, UNSW SydneyDaniel Reeders, PhD Candidate, ANU School of Regulation and Global Governance (RegNet), Australian National UniversityKathryn Snow, Epidemiologist, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1003642018-08-15T10:23:20Z2018-08-15T10:23:20ZOvercoming vaccination myths: Could addressing the facts during prenatal visits help?<figure><img src="https://images.theconversation.com/files/230453/original/file-20180802-136652-12j1hip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Studies suggest that pregnant women might be influenced by medical myths on social media. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/amazed-pregnant-woman-watching-media-content-551975254?src=JeLj7b39Cyx1OxjPsB8KUg-1-7">Antonio Guillem/Shutterstock.com</a></span></figcaption></figure><p>During pregnancy, expectant parents spend countless hours sifting through online resources to make the “right” medical choices for their baby. In addition to decorating a nursery and playing baby shower games, pregnant women often are glued to their smartphones, seeking advice from friends and strangers. </p>
<p>A pregnant woman’s Facebook news feed provides one window into motherhood, and the connections, articles and advice delivered by a Facebook news feed offer suggestions – both wanted and unwanted.</p>
<p>Despite expressing skepticism of the accuracy of digital resources and a pervasive fear of “fake news,” <a href="https://www.ncbi.nlm.nih.gov/pubmed/26075413">pregnant women “Google it up” </a> to gain information and health advice. Mothers-to-be have been found to rely on social media more frequently and with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3650729/">greater intensity at the transition to parenthood</a>.</p>
<p>However, the internet has been dubbed a <a href="https://www.ncbi.nlm.nih.gov/pubmed/22172504">“postmodern Pandora’s box.”</a> Misinformation and rumors abound on many health topics, but particularly in regards to childhood vaccinations. <a href="https://link.springer.com/content/pdf/10.1140%2Fepjst%2Fe2015-50319-0.pdf">False claims</a> and widely perpetuated myths, such as the discredited assertion that vaccinations cause autism, have been <a href="https://link.springer.com/content/pdf/10.1140%2Fepjst%2Fe2015-50319-0.pdf">declared a threat</a> to modern society. According to the <a href="https://www.cdc.gov/vaccines/vac-gen/whatifstop.htm">Centers for Disease Control and Prevention,</a> community immunity requires that a certain percentage of the population be vaccinated to maintain coverage against dangerous diseases for all.</p>
<p>I study health communication, and I have analyzed some of these trends. I see problems when expectant parents accept medical myths. I also see opportunities to change the narrative to an accurate one. </p>
<h2>Persistent falsehoods</h2>
<p>Although overall vaccination rates in the United States <a href="https://www.cdc.gov/mmwr/volumes/66/wr/mm6643a3.htm">remain high</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3906279/">social networks</a> sometimes support grassroots mobilization of mothers against childhood vaccines. This allows personal narratives to take root and be shared more. </p>
<p>My recent study, not yet published, found that more than 30,000 members in the largest closed anti-vaccination Facebook group influence first-time, pregnant and new mothers in their decision-making process for their own children. In some instances, I found that a mother’s expressed concern would transition from fear of protecting her child from measles to a more intense fear of more than 200 alleged side effects. </p>
<p><a href="https://arxiv.org/ftp/arxiv/papers/1801/1801.02903.pdf">Another 2018 study</a> analyzed 2.6 million Facebook users’ interactions over more than seven years, identifying distinct, opposing pro- and anti-vaccination narratives. Users self-select the content they wish to view based on their own belief systems, ignoring all other content. Researchers found that posts from anti-vaccination advocates received more user comments. And anti-vaccination groups are growing more rapidly in <a href="https://arxiv.org/ftp/arxiv/papers/1801/1801.02903.pdf">comparison to pro-vaccination groups</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/230454/original/file-20180802-118933-1ue8tpq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Images of crying babies receiving vaccinations often cause worry among mothers-to-be.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/closeup-shot-pediatrician-giving-three-month-278131262?src=PiG4-30Sa_QUAN0mMDD9mw-1-24">Dmitry Naumov/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Similarly, another study identified that the majority of YouTube videos about infant vaccination showed <a href="https://ruor.uottawa.ca/bitstream/10393/33649/1/12887_2013_Article_1068.pdf">babies in pain and distress</a>. Videos that <a href="https://www.ncbi.nlm.nih.gov/pubmed/28362544">disapprove of vaccinations</a> received the most likes, views and shares. In contrast, <a href="https://www.youtube.com/watch?v=HwugWGTrTqM">pro-vaccination YouTube videos</a> received far fewer likes, shares and views. </p>
<p>Put simply, anti-vax videos are increasingly playing up the risks of vaccination, which mainly include <a href="https://www.cdc.gov/vaccines/parents/vaccine-decision/index.html">redness and swelling</a> where the shot is given and, in very rare cases, other side effects. These anti-vax videos consistently downplay the benefit of protection from life-threatening diseases.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/25444525">A large study in New York state</a> identified one in four students following an alternate, nonscientifically based vaccination schedule. An alternate schedule may include selectively vaccinating or delaying certain vaccines. Essentially, parents of these children are following their own schedule, or a schedule found in a book or magazine, but not the CDC recommended schedule. <a href="https://www.texastribune.org/2016/07/14/see-studnet-vaccine-exemptions-school/">Students in private schools,</a> or those who come from more affluent families with parents who have received higher levels of education, are more likely to opt out. </p>
<p>Physicians such as <a href="https://www.pbs.org/wgbh/frontline/article/robert-w-sears-why-partial-vaccinations-may-be-an-answer/">Robert Sears</a> provide advice contrary to consensus by the medical community and use digital channels, including propaganda <a href="https://www.youtube.com/watch?v=rGq4Fbqw9K4">videos</a>, to raise concerns about the safety of vaccinations. The Medical Board of California recently placed Sears on <a href="https://www.forbes.com/sites/tarahaelle/2018/07/01/pediatrician-bob-sears-license-temporarily-revoked-after-questionable-vaccine-exemption/#452c48cdef60">probation</a> for allegedly writing inappropriate medical exemptions for vaccinations. </p>
<h2>Causing a cluster</h2>
<p>Parental refusal to vaccinate typically increases <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4927017/">in geographic clusters</a>, and when that happens, outbreaks of once-eliminated diseases, such as measles, occur. In 11 states, the number of kids not being vaccinated for nonmedical reasons has <a href="https://www.statnews.com/2017/01/20/vaccine-exemptions-states/">exceeded any point in the past five years</a>. Infants, the elderly and immuno-compromised individuals are particularly vulnerable. </p>
<p>While women get a lot of information on birth plans and breastfeeding during standard prenatal care, my qualitative research suggests that they do not get much information about childhood vaccinations. In interviews and focus groups with more than 20 expectant mothers, some in their third trimester, all reported that providers had not initiated dialogue about childhood vaccinations. For first-time mothers, they reported our conversation was the first they had formally discussed this particular issue. Yet the American Academy of Pediatrics recommends that the first dose of the hepatitis B vaccination be <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/Pages/AAP-Recommends-That-Infants-Receive-First-Hepatitis-B-Dose-Within-24-Hours-of-Birth.aspx">administered within the first 24 hours of life.</a> </p>
<p><a href="https://www.acog.org/">The American College of Obstetricians and Gynecologists</a> and the <a href="http://nacpm.org/">National Association of Certified Professional Midwives</a> do not recommend that practitioners broach the subject of childhood vaccinations during pregnancy, focusing instead on maternal vaccinations during pregnancy and referring any childhood vaccination dialogue to the child’s pediatrician. </p>
<p>But what might happen if this changed? Could this be a solution? I strongly believe it could.</p>
<h2>A full-term medical press</h2>
<p>Even though 90 percent of expectant mothers report making childhood vaccination decisions before the birth of the baby, a full one-third of expectant mothers expressed feeling uninformed, with <a href="http://www.abc.net.au/news/2017-09-08/first-time-mothers-uncertain-about-vaccinating-their-children/8883710">first-time mothers</a> identifying as more vaccine hesitant.</p>
<p>As one expectant mother in her third trimester in Gainesville, Florida recently said in an interview with me:</p>
<p>“I think that there’s extreme lack of communication. I think that childhood vaccination information should be relayed. That way you have the information you need before something happens, and then it’s too late to make an informed decision.” </p>
<p><a href="https://www.researchgate.net/publication/51923983_Missed_Opportunities_A_National_Survey_of_Obstetricians_About_Attitudes_on_Maternal_and_Infant_Immunization">In a survey,</a> 98 percent of OB-GYNs revealed they believe childhood vaccinations to be important, but less than half believed they could influence expectant mothers. </p>
<p>In an interview, a midwife in Gainesville stated childhood vaccination discussions are not in her “standard scope of practice,” explaining that beyond a basic handout, she typically refers questioning mothers-to-be to a pediatrician. </p>
<p>Although the American Academy of Pediatrics recommends finding a pediatrician during the third trimester of pregnancy, <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/Pages/Expectant-Parents-Encouraged-to-Visit-Pediatrician-Before-Birth-of-Baby.aspx">a 2018 survey showed that only 5 to 39 percent of first-time parents actually attend a prenatal visit with their baby’s chosen pediatrician.</a> Urban poor pregnant women and pregnant women in rural areas are less likely to attend a prenatal pediatric visit. </p>
<p>In the absence of comprehensive information about childhood vaccinations, Dr. Google may take over.</p>
<p>I believe the following things would help to get the truth out:</p>
<ul>
<li>A more active physician voice on social networking sites, connecting patients with evidence-based sources as opposed to anti-vaccination propaganda. </li>
<li>Standard policy by the American College of Obstetricians and Gynecologists recommending childhood vaccination discussions to occur during the third trimester of pregnancy, particularly surrounding the first vaccine. <a href="https://www.ncbi.nlm.nih.gov/pubmed/17826581">Research</a> has suggested that this could help educate parents.</li>
<li>Standard policy by National Association of Certified Professional Midwives to include more information about childhood vaccinations during prenatal care. </li>
<li>Increased efforts to orchestrate prenatal pediatrician’s visits to connect mothers-to-be with their child’s future doctor to discuss vaccination, with a special emphasis on connecting first-time mothers with a pediatrician during the third trimester.</li>
</ul><img src="https://counter.theconversation.com/content/100364/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amanda Sams Bradshaw 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>Pregnant women often get medical information from social media and websites, many of which contain misleading and false information about vaccination. Could OB-GYNs help educate them better?Amanda Sams Bradshaw, Ph.D. candidate in Advertising, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/825872017-10-23T03:41:12Z2017-10-23T03:41:12ZHealth Check: do boys really have a testosterone spurt at age four?<figure><img src="https://images.theconversation.com/files/182699/original/file-20170821-20193-p8clu9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There's lots going on in the lives of four-year-old boys, including how to regulate their emotions. Let's not blame their hormones.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/594435866?src=vUIze5kpCfgxwZaN2ReyJg-1-54&size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>The idea that four-year-old boys have a spurt of testosterone is <a href="http://www.powerfulmothering.com/that-tricky-thing-called-testosterone/">often used to explain</a> challenging behaviour at this age.</p>
<p>But how did this idea come about? Is there any truth in it? And if not, what else could explain their behaviour?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/helicopter-snowplow-or-free-range-whats-your-parenting-style-15123">Helicopter, snowplow or free range – what's your parenting style?</a>
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</em>
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<p>Psychologist and author Stephen Biddulph <a href="http://www.canberratimes.com.au/preschoolers/preschooler-development/when-testosterone-kicks-in-for-young-boys-20140625-3asn6.html">is often credited</a> with being the source of the idea that four-year-old boys have a testosterone spurt.</p>
<p>Although he mentioned it in his bestselling book <a href="http://finch.com.au/books/steve-biddulphs-raising-boys-4th-edition">Raising Boys</a>, he was writing about someone else’s work:</p>
<blockquote>
<p>According to Professor Mitchell Harman in the US Department of Aging, boys undergo a testosterone burst at age four … Not all researchers have agreed with this finding though, so it remains controversial.</p>
</blockquote>
<p>Biddulph said Professor Harman wrote about this for an article in the men’s magazine Esquire in 1999 and “stood by these findings” when contacted in 2015.</p>
<h2>So, what does the evidence say?</h2>
<p>As a researcher and adolescent endocrinologist, who specialises in puberty hormones, I can say there is no evidence this testosterone spurt exists. Many studies of hormones in boys in peer-reviewed journals <a href="http://www.tandfonline.com/doi/abs/10.3109/00365513.2014.942694">confirm</a> <a href="https://www.karger.com/Article/Pdf/358560">this</a>.</p>
<p><a href="https://www.news-medical.net/health/Testosterone-Physiological-Effects.aspx">Raised levels of testosterone</a> are not possible when testes (where testosterone is made) are small and levels of the hormone that stimulates testosterone production is low.</p>
<p>The only time when a four-year-old’s testosterone level is high is in a serious and uncommon condition called <a href="http://www.msdmanuals.com/en-au/professional/pediatrics/endocrine-disorders-in-children/precocious-puberty">precocious puberty</a>, where boys enter puberty and their testicles enlarge much earlier than usual.</p>
<h2>Yes, testosterone rises, but not at this age</h2>
<p>There are rises in testosterone during a boy’s development, which coincide with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989000">major brain development</a>. But these don’t happen at the age of four.</p>
<p>Testosterone first increases to puberty-like levels in boys during the <a href="https://www.womenshealth.gov/pregnancy/youre-pregnant-now-what/stages-pregnancy">first two trimesters of pregnancy</a>. This testosterone is responsible for the development of the penis and scrotum, a process known as the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3443292">masculinisation of external genitalia</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/heres-what-you-need-to-know-about-testosterone-31687">Here's what you need to know about testosterone</a>
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</em>
</p>
<hr>
<p>The second testosterone increase occurs in the first six months or so of life. This <a href="https://link.springer.com/content/pdf/10.1007/978-1-4419-1795-9_39.pdf">mini-puberty</a> results in boys’ genitalia briefly looking more prominent, which many parents notice.</p>
<p>Puberty is the third and final rise in testosterone, with levels increasing 10- to 20-fold over two to three years. Puberty is a time of major physical growth accompanied by <a href="http://www.jneurosci.org/content/35/40/13539">significant behaviour changes</a>, clearly influenced by brain development. </p>
<h2>Yes, there are hormone changes, but not testosterone</h2>
<p>There are hormone changes starting at around five to six years in both sexes in a period known as <a href="https://www.ncbi.nlm.nih.gov/pubmed/21164255">adrenarche</a>. Perhaps this has also contributed to the confusion.</p>
<p>Adrenarche is the maturation of part of the adrenal glands where hormones similar to, but much weaker than, testosterone are made. Their most common effect is <a href="https://www.ncbi.nlm.nih.gov/pubmed/21164255">body odour</a>. However, researchers don’t know why exactly boys and girls have this phase. And no-one has yet seen any clear effects on childhood behaviour.</p>
<h2>No, testosterone doesn’t spurt</h2>
<p>Use of the word “<a href="https://en.oxforddictionaries.com/definition/spurt">spurt</a>” to describe testosterone production is also incorrect. </p>
<p>Testosterone does not spurt at any time of life. The word “spurt” creates a sense of rapidity and urgency, giving testosterone a reputation in childhood it does not deserve. Instead, when testosterone levels rise in puberty, it <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4949545/">increases gradually at first, then accelerates in mid to late puberty</a>.</p>
<h2>So, what else can explain behaviour?</h2>
<p>So is there an alternative explanation for boys’ behaviour at this age, which parents regularly report?</p>
<p>We see differences in boys’ and girls’ <a href="https://www.ncbi.nlm.nih.gov/pubmed/20826305">brains</a> and <a href="https://link.springer.com/article/10.1007/s00424-013-1268-2">behaviour</a> well before puberty. Rises in testosterone in the womb and during the mini-puberty in the first six months of life likely explain these. </p>
<p>Studies that look at behaviour in four to five-year-olds tend to focus on play and social interactions, because these are what children this age do most of the time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/187718/original/file-20170927-24193-1rt2joc.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">Boys and girls this age tend to have different styles of play.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/245148427?src=PgfeMmrAnQHDwA_WguLr5w-1-52&size=medium_jpg">from www.shutterstock.com</a></span>
</figcaption>
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<p>Such studies show boys and girls this age generally have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951011/">different ways of playing and communicating</a>. Boys’ play is generally more physical, engaging with mobile toys or building structures. Girls generally have more socially interactive play, and are more articulate. </p>
<p>Interestingly, girls with <a href="https://www.rch.org.au/uploadedFiles/Main/Content/MedEd/fracp/CAH%20PIR%202009.pdf">congenital adrenal hyperplasia</a>, when they are exposed to high levels of testosterone in the womb, tend to have more “<a href="https://www.ncbi.nlm.nih.gov/pubmed/12760514">rough and tumble</a>” play styles, consistent with a testosterone effect on early brain development.</p>
<h2>So, how might being four or five change boys’ behaviour?</h2>
<p>At this age, children <a href="http://raisingchildren.net.au/preschoolers/preschoolers.html">learn how to</a> interact with others, understand another’s needs, share, and to deal with new and unfamiliar situations.</p>
<p>So, children must learn to <a href="https://www.kidsmatter.edu.au/early-childhood/resources-support-childrens-mental-health/about-emotions/self-regulation">regulate their own emotions</a>, like fear, concern, upset and anger. </p>
<p>When children don’t do this, we see the emotional outbursts, which can be explosive. Children can struggle to either understand or articulate why they lost control of their emotions. Boys <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951011/">may respond</a> more physically and be less able to articulate what happened.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/talking-to-kids-about-emotions-matters-more-than-you-think-21955">Talking to kids about emotions matters more than you think</a>
</strong>
</em>
</p>
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<p>Learning how to regulate their emotions is an important skill for children to develop. Parents can <a href="https://www.kidsmatter.edu.au/early-childhood/resources-support-childrens-mental-health/social-development">model good emotional regulation</a>, make sure children have regular daily routines, enough time to practice play and <a href="https://www.ncbi.nlm.nih.gov/pubmed/28129449">enough sleep</a>. Praising positive behaviour and not overreacting to minor attention-seeking misbehaviour also helps.</p>
<p>We shouldn’t blame hormones for children’s behaviour. Instead, we need to better understand those behaviours.</p>
<p>For instance, persistent and distressing behaviours in a child may signal underlying anxieties, reaction to family stresses, which are felt but not understood, or be a result of <a href="http://jamanetwork.com/journals/jamapediatrics/fullarticle/2427470">adversities when they were younger</a>. So, if you are concerned, seek professional advice.</p>
<p>For all children, we need to prioritise <a href="https://www.cam.ac.uk/news/world-leading-academic-appointed-to-lead-play-research-centre">time to play</a>. That could mean space, action and permission to be noisy and boisterous.</p>
<hr>
<p><em>For more information about behaviour in preschoolers see the <a href="http://raisingchildren.net.au/preschoolers/preschoolers.html">Raising Children Network</a>. If you are concerned about your preschooler’s behaviour and want support, see <a href="https://healthyfamilies.beyondblue.org.au/age-1-5?&gclid=EAIaIQobChMIi4ei4eCh1gIVhggqCh3VdgheEAMYASAAEgJR5_D_BwE">beyondblue</a>.</em></p><img src="https://counter.theconversation.com/content/82587/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kate Steinbeck 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>Some parents think their four-year-old boy’s emotional outbursts and aggressive behaviour can be blamed on their hormones. Here’s why that’s a myth.Kate Steinbeck, Medical Foundation Chair in Adolescent Medicine, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/757152017-04-09T08:47:45Z2017-04-09T08:47:45ZDebunking myths about malaria and its vector, the mosquito<figure><img src="https://images.theconversation.com/files/164050/original/image-20170405-14626-wmjv97.jpg?ixlib=rb-1.1.0&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><em>Myths about diseases spread like wildfire. Malaria is a case in point. The Conversation Africa’s Health and Medicine Editor Joy Wanja Muraya asked Tabitha Mwangi to help sort out fact from fiction.</em></p>
<p><strong>Mosquitoes only bite at night.</strong></p>
<p>Not entirely true.</p>
<p>There are two types of mosquitoes that bite mostly at night; the <a href="http://www.mosquitomagnet.com/advice/mosquito-info/biting-insect-library/anopheles-mosquito">Anopheles mosquito</a> that transmits malaria and it’s noisier cousin, the <a href="https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=Culex+mosquito&*">Culex mosquito</a> which spreads <a href="http://www.who.int/lymphatic_filariasis/en/">lymphatic filariasis,</a> – also known as elephantiasis – that presents as severe swelling in the arms, legs or genitals.</p>
<p>A year-long <a href="https://www.ncbi.nlm.nih.gov/pubmed/26209103">study</a> in Western Kenya showed that 15% of the mosquitoes bite between 6pm to 9pm while the majority (85%) bite from 9pm till morning. Data from this study puts further emphasis on the value of sleeping under an insecticide treated bednet.</p>
<p>But there are other mosquitoes, such as the <a href="http://www.who.int/denguecontrol/mosquito/en/">Aedes mosquitoes</a> – easily identified by their zebra stripped legs – that are active mostly during the day. They spread viruses that cause <a href="https://www.sciencedaily.com/releases/2016/11/161114162628.htm">dengue, zika, Chikugunya</a> and <a href="http://www.who.int/mediacentre/factsheets/fs207/en/">rift valley fever</a>. </p>
<p>The fact that this mosquito is active during the day makes it harder to control the diseases it spreads because bed nets aren’t an option.</p>
<p><strong>Eating garlic before I sleep will repel mosquitoes.</strong></p>
<p>There’s no scientific evidence to support this.</p>
<p>Garlic does produce a sulphur compound known as allicin which has some anti-bacterial, anti-fungal and anti-parasitic activities. Researchers have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472199/">looked at</a> it’s impact on mice that have been infected with malaria. In mice, use of allicin leads to a reduction in the number of malaria parasites in the blood, the higher the dose of allicin, the longer the mice survived. But no research has been done on its effect on the human immune system.</p>
<p>Garlic oils are marketed as <a href="http://www.savatree.com/garlic-insect-repellent.html">insect repellents</a> but their efficacy is uncertain.</p>
<p><strong>Mosquitoes like to bite women and children more than men.</strong></p>
<p>This isn’t true, though there’s some evidence that they’re partial to pregnant women. </p>
<p>In The Gambia researchers found that pregnant women are <a href="https://www.ncbi.nlm.nih.gov/pubmed/10859048">twice</a> as attractive to mosquitoes than non pregnant women.</p>
<p>The research involved 36 pregnant women and 36 women who weren’t pregnant. The two groups slept in separate huts under bed nets. In the morning, researchers collected and counted the mosquitoes found in the separate huts. </p>
<p>Twice as many mosquitoes were found in the huts in which the pregnant women had slept. There were two possible explanations for this. The first is that mosquitoes are attracted to carbon dioxide which pregnant women produce more of. In advanced pregnancy, women exhale <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1127358/">21% greater volumes</a> than non pregnant women.</p>
<p>The second possible explanation is that pregnant women’s tummies are <a href="http://www.sciencedirect.com/science/article/pii/S1836955315000946">0.7°C warmer</a> than non pregnant women which could attract mosquitoes.</p>
<p>But there was an additional factor that the researchers suggested could have affected the results. Pregnant women – particularly women in advanced pregnancy – had to leave their huts at night more often than non-pregnant women because they need to urinate frequently. </p>
<p><strong>Mosquitoes die after feeding.</strong></p>
<p>This is not true. Male mosquitoes <a href="http://insectcop.net/what-do-mosquitoes-eat/">feed</a> on sugary things while female mosquitoes need blood for their eggs to develop.</p>
<p>After feeding on blood, a female mosquito will rest to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2581474/">digest the blood</a> and wait for the eggs to be ready. </p>
<p>The female mosquito rests for about two to three days then lays her eggs in <a href="https://www.megacatch.com/mosquito-faqs/mosquito-life-cycle.html">water</a>. After laying between 50 to 200 eggs, she then searches for another blood meal in order to lay another batch of eggs.</p>
<p>During her lifetime the female tries to <a href="https://www.megacatch.com/mosquito-faqs/mosquito-life-cycle.html">lay</a> as many eggs as she can which requires several blood meals.</p>
<p>In a laboratory, female mosquitoes can live for up to one month. But in natural conditions, few survive beyond one to two weeks.</p>
<p><strong>Once you get malaria, you will never get it again.</strong></p>
<p>Researchers have spent years monitoring people in malaria endemic areas to learn the patterns of immunity. </p>
<p>My <a href="https://www.ncbi.nlm.nih.gov/pubmed/15871128">PhD research</a> involved collecting data on malaria from about 1,000 people in Coastal Kenya for two years. Children under five years had, on average, one clinical attack of malaria every year.</p>
<p>Malaria cases declined steeply after that and it was rare for adults who lived in this malaria endemic areas to have clinical attacks. </p>
<p>Other studies have shown that when highly immune adults spent long periods of time in places where they weren’t being bitten by infected mosquitoes, they could lose some of that<a href="https://www.ncbi.nlm.nih.gov/pubmed/25656623">immunity</a>.</p>
<p>Scientists know that solid immunity to malaria only occurs in people who are constantly challenged. But it’s still not clear how this happens. This is one of the reasons why developing a <a href="http://www.malariavaccine.org/about-us">malaria vaccine </a> that works well has proved so difficult.</p>
<p><strong>Mosquitoes only like the blood of humans.</strong></p>
<p>This is true for some mosquitoes, but because female mosquitoes need a blood meal, most will take it from wherever they can find it. For example, <a href="https://www.ncbi.nlm.nih.gov/pubmed/26857915">livestock</a> kept outside the homestead can attract mosquitoes. There’s even been a suggestion that <a href="https://www.ncbi.nlm.nih.gov/pubmed/28069065">cattle should be treated with insecticide</a> as a malaria control strategy.</p><img src="https://counter.theconversation.com/content/75715/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tabitha Mwangi 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>There are lots of tall tales about mosquitoes and how malaria is transmitted. Here are sturdy facts on the disease.Tabitha Mwangi, Senior Lecturer, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/682382016-12-05T00:33:03Z2016-12-05T00:33:03ZHealth Check: do home remedies for common warts really work?<figure><img src="https://images.theconversation.com/files/147693/original/image-20161128-22727-nap2vl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Covering warts with duct tape is one home remedy for this common skin condition. But does it work?</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-16177381/stock-photo-a-roll-of-grey-duct-tape-close-up-shot.html?src=LFa6zZb1uvcIsJgh3bcs4g-2-43">from www.shutterstock.com</a></span></figcaption></figure><p><a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/warts">Common warts</a> can be hard to get rid of, so many people turn to home remedies. An internet search suggests everything from mashed banana to duct tape. But do these home remedies actually work?</p>
<p><a href="http://www.uptodate.com/contents/skin-warts-beyond-the-basics">Warts</a> develop when the human papillomavirus (<a href="https://theconversation.com/au/topics/human-papillomavirus-3966">HPV</a>) infects cells in the skin and mucous membranes (the mouth and genitalia). There are more than 150 sub-types of HPV, which cause different types of warts in different parts of the body. </p>
<p>HPV is transmitted through direct contact with another person’s wart or with objects and surfaces exposed to the virus. HPV is more likely to infect skin that is injured, damaged or macerated (such as soggy, sweaty feet). Normal skin can also be infected and it can take more than six months after exposure to the virus for a wart to appear.</p>
<p>Common warts (also called verrucae vulgaris) can occur in any body area, but are most common on the fingers, hands, knees and elbows as these are parts commonly injured. Warts begin as round or oval raised lumps on the skin and can be lighter or darker than the skin around them. They can contain black spots called “seeds”.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=908&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=908&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=908&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1141&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1141&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147699/original/image-20161128-22745-1id9490.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1141&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Warts are common on parts of the skin that are easily injured, like the knees.</span>
<span class="attribution"><span class="license">Author provided</span></span>
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</figure>
<p><a href="http://kidshealth.org/en/parents/wart.html">Children</a> and young adults are most at risk of developing common warts. Certain jobs, including handling meat, fish and poultry, can also increase your risk. People with skin conditions, such as eczema, are also more likely to develop them, as are those with any condition that weakens their immune system (such as AIDS).</p>
<h2>What does the research say?</h2>
<p>Not every wart needs to be treated. But if you are concerned about pain or discomfort, how it looks and the risk of a wart spreading to another part of the body, you may want to treat it.</p>
<p>Salicylic acid has the <a href="http://onlinelibrary.wiley.com/doi/10.1111/bjd.13310/full">strongest evidence</a> as first-line treatment for common warts. This is the most common ingredient in wart paints which, as the name suggests, are treatments you apply to the skin. Products containing salicylic acid come as a lotion, ointment, pad or patch, which you can buy at a pharmacy without a prescription. Common examples include Duofilm and Wart Off.</p>
<p>First, soak the wart in warm water and rub it with a pumice stone before applying the treatment.</p>
<p>Another option is to freeze a wart by applying liquid nitrogen, which your general practitioner (GP) or dermatologist can do in their office. The doctor sprays liquid nitrogen directly onto the wart for 10-20 seconds in a process known as cryosurgery. But this can be painful, especially for younger children. </p>
<p>These treatments don’t always work and researchers estimate that <a href="http://onlinelibrary.wiley.com/doi/10.1111/bjd.13310/full">success rates</a> for over-the-counter wart paints and liquid nitrogen vary from 10% to 90%. This is why many people turn to unconventional home treatments.</p>
<h2>The stuff of legends</h2>
<p>Home remedies for warts are the stuff of legends. The idea behind many of them is to boost the immune system or break down the wart and the HPV. Where warts seem to improve, it is difficult to tell if the body’s immune system is attacking the wart, or the home remedy is working.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=515&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=515&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147704/original/image-20161128-22754-yve6hy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=515&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">Wart on your finger? Which home remedies have you tried?</span>
<span class="attribution"><span class="license">Author provided</span></span>
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</figure>
<p>Unconventional treatments include applying apple cider vinegar, cut potatoes, orange peel, aloe vera, clear nail polish, raw garlic, mashed banana or milk of dandelion (its sap).</p>
<p>Unfortunately, there is no research to show they actually work. Part of the problem is some warts simply disappear by themselves, making it hard to say whether the treatment worked or the wart would have disappeared anyway.</p>
<h2>What about duct tape?</h2>
<p>Researches have studied whether covering the wart with duct tape works, but have had conflicting results. <a href="https://www.ncbi.nlm.nih.gov/pubmed/12361440">One study</a> found warts improved significantly using duct tape compared with liquid nitrogen, while <a href="https://www.ncbi.nlm.nih.gov/pubmed/17372095">another</a> found duct tape didn’t help.</p>
<p>Researchers don’t know how duct tape might work. It could suffocate the wart. Alternatively, it could irritate the surrounding skin to produce inflammation. But there is no evidence for either.</p>
<p>If you use duct tape, we suggest using the silver type, which sticks to the skin more effectively than other types of duct tape. Cover the wart for six days, then remove the tape and soak the wart in warm water for 20 minutes. Use a pumice stone to remove the wart. Keep the wart uncovered overnight, then reapply the duct tape for another six days.</p>
<p>If the wart has not responded within two weeks, it is unlikely to respond.</p>
<p>Do not use duct tape if you are at risk of developing ulcers or skin infections, for instance if you have diabetes, poor blood circulation, poor nerve function or have sensitive skin.</p>
<h2>Watch out</h2>
<p>Never try to remove the wart yourself as this carries a high risk of infection, bleeding and scarring. Self-surgery also increases the risk of the wart spreading. Avoid scratching and picking the wart for the same reasons. </p>
<p>Any topical treatment (from the doctor or a home remedy) may cause an allergic skin reaction. If you see redness or a rash, stop using the treatment immediately and see your doctor. </p>
<p>If you are pregnant or breastfeeding, always consult a doctor before treating a wart; skin treatments are absorbed into the circulation and may harm the unborn baby or breastfeeding infant.</p>
<h2>They come, they go, they come back again</h2>
<p>Warts in people with working immune systems generally get better without treatment. About 20% resolve within three months and two-thirds within two years. Efforts to promote a healthy immune system, including a healthy diet, exercise and enough sleep, are likely as effective as any home remedy.</p>
<p>Unfortunately, it’s very common for warts to return.</p>
<p>If you have a wart that is causing pain or discomfort, affecting your confidence, or you have recurrent outbreaks, see your GP.</p><img src="https://counter.theconversation.com/content/68238/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Common warts can be hard to treat. No wonder people turn to home remedies, like duct tape and vinegar. But do they really work?Rodney Sinclair, Professor of Dermatology, The University of MelbourneWilliam Cranwell, Doctor, Melbourne HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/612452016-06-28T09:42:10Z2016-06-28T09:42:10ZSex and other myths about weight loss<figure><img src="https://images.theconversation.com/files/127621/original/image-20160621-13005-1u6c1at.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Contrary to myth, sex is not good exercise. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&searchterm=sex&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=354146012">From www.shutterstock.com</a></span></figcaption></figure><p>The estimated annual health care costs related to obesity are over $210 billion, or nearly 21 percent of annual <a href="http://www.sciencedirect.com/science/article/pii/S0167629611001366">medical spending in the United States</a>. Americans spend $60 billion on <a href="http://www.marketdataenterprises.com/studies/#WORKSITEWEIGHTLOSS">weight loss products</a> each year, trying everything from expensive meal replacement products to do-it-yourself programs on the latest cell phone apps. We gather weight loss advice, voluntarily or involuntarily, from news outlets, social media and just about everyone. </p>
<p>Americans have known for 15 years that obesity is an epidemic; the surgeon general <a href="http://www.cdc.gov/nccdphp/dnpa/pdf/CalltoAction.pdf">declared it so in 2001</a>.
Despite intense efforts to prevent and treat obesity, however, studies published June 7 in the Journal of the American Medical Association showed that <a href="http://jama.jamanetwork.com/article.aspx?articleid=2526639">35 percent of men, 40 percent of women</a>, and <a href="http://jama.jamanetwork.com/article.aspx?articleid=2526638">17 percent</a> of children and adolescents are obese. Even more worrisome, the rates continue to rise among women and adolescents. </p>
<p>In fact, experts predict that this generation of children may be the first in 200 years to have a shorter life expectancy than their parents, <a href="http://www.nejm.org/doi/full/10.1056/NEJMsr043743%5D">likely due to obesity</a>.</p>
<p>So what is our society doing wrong? Clearly, what doctors and policy makers have been doing for the last 15 years to address this epidemic is not working.</p>
<h2>Weight loss myths have broad appeal</h2>
<p>An article from 2013 in the<a href="http://www.nejm.org/doi/pdf/10.1056/NEJMsa1208051"> New England Journal of Medicine (NEJM) </a> identified common myths surrounding obesity from popular media and scientific literature. The authors defined myths as ideas that are commonly held, but go against scientific data. Could these myths be keeping us from treating obesity effectively? As family physicians who treat overweight patients every day, we believe they do. Not only can these myths discourage people, they also provide misinformation that can prevent people from reaching their weight loss goals.</p>
<p>You might be surprised to hear some of these myths:</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/127622/original/image-20160621-13005-14yztmp.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">Just switching chips for carrots is not enough.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/dl2_lim.mhtml?src=sbpyNVah69YO8Gy67EEX6w-1-71&clicksrc=download_btn_inline&id=32493988&size=medium_jpg&submit_jpg=">From www.shutterstock.com</a></span>
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</figure>
<p>Myth 1: Small changes in your diet or exercise will lead to large, long-term weight changes. </p>
<p>Unfortunately, this is not true. In weight loss, two plus two may only equal three instead of four. Small changes simply do not add up since physiologically, your body tries to stay the same weight. This doesn’t mean that making small healthy choices don’t matter, because even small things you do to stay healthy matter. It just means you are not likely to meet your weight loss goals by just taking one less bite. It’s likely going to take bigger changes in your diet and exercise.</p>
<p>Myth 2: Setting realistic goals when you are trying to lose weight is important because otherwise you will feel frustrated and lose less weight.</p>
<p>Patients often come in with ambitious goals for weight loss, and we as family physicians nearly always say- <em>go for it</em>! (within safety and reason). There is no evidence that shooting for the stars leads to frustration. If anything, aiming for a larger goal <a href="http://ajpendo.physiology.org/content/298/3/E449.long">may lead to better weight-loss outcomes</a>.</p>
<p>Myth 3: Losing a lot of weight fast doesn’t keep weight off as well as losing a few pounds slowly. </p>
<p>Again, studies have shown that losing a larger amount of weight fast in the beginning (maybe while you are super motivated) has been associated with lower weight in the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3780395/">long-term</a>. There just isn’t evidence to go “slow and steady” when it comes to weight loss. </p>
<p>Finally, to our favorite one:</p>
<p>Myth 4: Having sex one time burns about as many calories as walking a mile.</p>
<p>Sorry to disappoint, but for an average sexual encounter (lasting 6 minutes!), an average man in his 30s burns just 20 calories. And as the NEJM articles further explains, this is just 14 more calories than just sitting and watching TV. So if the thought went through your head that <a href="http://www.ncbi.nlm.nih.gov/pubmed/6476990">sex may be your exercise</a> for the day, you should think again. </p>
<h2>Myths take hold</h2>
<p>As family physicians, we were curious to know if our own patients in clinic might believe in these myths. Maybe in the few short years since the NEJM paper was published, this information has permeated through popular media, and corrected itself. Everyone must know these basic facts about obesity, right?</p>
<p>To figure this out, we conducted a study of over 300 people in the waiting room of our diverse academic family medicine clinic. People who participated in our survey had an average age of 37, were mostly female (76 percent), had at least some college education (76 percent), and were a mix of non-Hispanic black (38 percent) and non-Hispanic white (47 percent). </p>
<p>The grand majority of people we surveyed still believed these myths (Myth 1: 85 percent, Myth 2: 94 percent, Myth 3: 85 percent, Myth 4: 61 percent)! Even more interestingly, there were no differences in what people believed across gender, age, or educational levels. These myths were pervasive. </p>
<p>How can we expect people to lose weight if most do not know the basics of weight loss? We didn’t need to go far before we realized that these myths are still found in popular media. In some cases, physicians themselves may fall victim to these myths. </p>
<p>Of course, healthcare providers should only give evidence-based advice to patients about weight loss in order to optimize their chance of success. Studies have shown that when primary care <a href="http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0053919/">doctors provide advice</a> on weight loss, patients are more likely to attempt to change their behaviors related to weight. However, even giving better and more advice may not be enough.</p>
<p>The first step is to acknowledge that patients are likely influenced by the myths that are so easily found online and among the advice given by friends and family. This means patients must be particularly savvy consumers of health information and to seek out information from reputable sources. This also means that educating and empowering overweight patients is only one part of the solution. Informing those - friends, family, and also the media - who <em>influence</em> overweight patients is also important if we want to change the trajectory of obesity in the U.S. </p>
<p>If we don’t translate the research on obesity into practice, we cannot expect this problem to improve in our lifetime. We will only have a chance if we use what we know about weight loss and drop these myths.</p><img src="https://counter.theconversation.com/content/61245/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tammy Chang receives funding from the National Institutes of Health. </span></em></p><p class="fine-print"><em><span>Angie Wang 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>Losing weight is hard enough to do without myths interfering in the process. Information based on evidence, not legend, is important. Doctors aren’t enough. Friends, family, media need to be on board.Tammy Chang, Assistant Professor, Family Medicine, University of MichiganAngie Wang, Resident, Department of Family Medicine, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/532672016-01-20T10:54:57Z2016-01-20T10:54:57ZWhy Mark Zuckerberg was right to vaccinate his daughter<figure><img src="https://images.theconversation.com/files/108724/original/image-20160120-26120-1oez5qe.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mark Zuckerburg's Facebook post.</span> <span class="attribution"><a class="source" href="https://theconversation.com/drafts/53267/edit">Facebook</a></span></figcaption></figure><p>Facebook co-founder Mark Zuckerberg recently posted a photo on the social networking site of his two-month-old daughter in the doctor’s surgery waiting to be vaccinated. It provoked a <a href="http://www.mirror.co.uk/news/technology-science/technology/mark-zuckerberg-shared-photo-daughter-7172167">storm on social media</a>, with millions of people commenting on the pros and cons of vaccination. </p>
<p>So was Zuckerberg right to have his child vaccinated? You take your perfectly healthy, happy baby to the doctor, she stabs her in the leg with a needle and you’re left holding a child that screams the place down for two minutes. </p>
<p>Well, it’s either that or risk catching meningitis, pneumonia, polio, diphtheria, measles, tetanus, or rubella. </p>
<p>In 1980, measles alone caused around <a href="http://www.who.int/mediacentre/factsheets/fs286/en/">2.6m deaths</a>. Global immunisation has brought this down, but still 115,000 people died from measles in 2014, mostly small children. Why, when we have a safe and effective vaccine against measles?</p>
<p>There are many logistical obstacles to successful vaccination globally, especially in poor countries, but that’s a different discussion. Let’s instead focus on busting some vaccination myths that have contributed to the recent rise of several infectious diseases in developed countries.</p>
<h2>Myth 1: MMR vaccine causes autism</h2>
<p>Rarely has a piece of misinformation single-handedly caused so much damage. In 1998, a Lancet paper by Andrew Wakefield proposed a causal link between the MMR (measles, mumps, rubella) vaccine and autism. Autism is usually diagnosed in preschool children (four-year-olds in the UK), and the second dose of MMR is given between ages three and four. The two can coincide, but there is no causality. </p>
<p>A formal inquiry found the research fraudulent and unethical – the children with autism were subjected to unnecessary invasive procedures such as colonoscopies and lumbar punctures. It was discredited and the <a href="http://tinyurl.com/lla8zg">paper retracted</a>. But the damage was done. The MMR vaccine uptake in the UK fell <a href="http://www.bbc.co.uk/news/uk-wales-politics-23244628">from 94% to under 70%</a>. In 2013, measles returned, resulting in serious illness, hospitalisation and even deaths in the <a href="http://www.his.org.uk/files/9213/8442/3157/FINAL_MEASLES_OCT_REPORT.pdf">UK</a> and <a href="http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6236a2.htm">US</a>. </p>
<h2>Myth 2: The HPV vaccine isn’t safe</h2>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/108701/original/image-20160120-26085-egoog4.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">Human papilloma virus (HPV)</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=ijmhqfc31099rs2efw7&searchterm=human%20papillomavirus&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=363779750">www.shutterstock.com</a></span>
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</figure>
<p>This claim is based on selective reporting of unexpected symptoms following a vaccination. Since 1990 health providers are required to report all adverse events that occur after vaccination, the <a href="https://vaers.hhs.gov/index">VAERS (Vaccine Adverse Event Reporting System)</a>. To date, over 30,000 adverse events and 200 deaths have been recorded for the new HPV vaccine Gardasil (from nearly <a href="http://www.hse.ie/eng/health/immunisation/pubinfo/schoolprog/hpv/get/">200m administered doses</a>). When a vaccine starts collecting bad reports, the number of reported “adverse events” goes up sharply. This does not mean the vaccine is the cause of these events, or deaths. What it means is that a death occurred after the person was vaccinated. People of all ages die worldwide every day. Some will have even received a vaccine prior to their death. </p>
<p>The only way to ensure that the reported adverse events are linked to a vaccine is to compare the number of the same events in a similar but unvaccinated sample of the population.</p>
<p>In November 2015, the European Medicines Agency completed a thorough <a href="http://www.ema.europa.eu/docs/en_GB/document_library/Referrals_document/HPV_vaccines_20/Opinion_provided_by_Committee_for_Medicinal_Products_for_Human_Use/WC500197129.pdf">review of HPV vaccine safety</a> and found no concerns. </p>
<h2>Myth 3: Vaccines contain toxic chemicals</h2>
<p>Aluminium salts are commonly added to improve the immune response to the vaccine. Aluminium occurs naturally in breast milk, formula milk, some foods and drinking water. The total amount of infant exposure through food and vaccination is well within <a href="http://www.fda.gov/BiologicsBloodVaccines/ScienceResearch/ucm284520.htm">the recommended safe levels</a>. </p>
<p>Thiomersal is a vaccine preservative containing a form of mercury that is easily excreted from the body (unlike methyl mercury found in tuna fish). The concerns about its toxicity are only theoretical and have not been scientifically proven. Thiomersal is not found in the childhood vaccines routinely used in the UK. </p>
<p>Formaldehyde is used in vaccine production to inactivate toxins from bacteria and viruses. A pear contains around 50 times more <a href="http://www.harpocratesspeaks.com/2012/04/demystifying-vaccine-ingredients.html">formaldehyde</a> than is found in any vaccine.</p>
<p>Unlike most drugs, the vaccine patient information leaflets list every ingredient used in the vaccine production, including trace substances, so that anyone with a severe allergy to any of these substances is consulted prior to vaccination. </p>
<h2>Myth 4: Vaccines can give you the disease they’re meant to be protecting you from</h2>
<p>It is impossible to get a disease from a vaccine made with killed bacteria or viruses, or made with only part of the bacteria or virus. In rare cases, vaccines that contain a live weakened virus can cause a mild form of the disease they protect against. The live oral polio vaccine did cause polio in a handful of cases and has not been used in the UK <a href="http://www.britishpolio.org.uk/polio-and-post-polio-syndrome/polio-and-vaccination/">since 2004</a>. The MMR vaccine very occasionally causes a mild form of measles or mumps that can last for a <a href="http://www.nhs.uk/conditions/vaccinations/pages/mmr-vaccine.aspx">day or two</a>. This kind of vaccine is only a risk to children with weak immune systems, such as those with cancer, who instead have to rely on protection through <a href="https://theconversation.com/herd-immunity-and-measles-why-we-should-aim-for-100-vaccination-coverage-36868">herd immunity</a>. </p>
<h2>Myth 5: Vaccines only profit Big Pharma</h2>
<p>Yes, vaccines are profitable, but far less profitable than most drugs, amounting to only 1-2% of <a href="http://magazine.jhsph.edu/2002/fall/vaccines.html">global pharmaceutical sales</a>. It takes decades and hundreds of millions of dollars in investment to <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1551949/">develop and licence one vaccine</a>. Without recouping these costs there would be no investment to develop new vaccines. Some vaccines are too costly for global coverage – although the manufacturers sell them at a reduced price to the developing countries and organised vaccination initiatives. And, as we are currently in the <a href="http://www.who.int/immunization/global_vaccine_action_plan/DoV_GVAP_2012_2020/en/">Decade of Vaccines</a>, greater vaccine accessibility and improved pricing transparency are high on the agenda of the WHO and GAVI (a Global Vaccine Alliance), and major funders such as the Gates Foundation. </p>
<p>We are fortunate to live in a time where we have access to vaccines against many terrible diseases. We should take advantage of this. As most parents will know, babies and young children are particularly prone to infections. Don’t compromise your child’s health by denying them vaccination. If they do catch something, it might just be too late.</p><img src="https://counter.theconversation.com/content/53267/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anita Milicic 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>Myths about vaccines have resurfaced once again. Here is why you shouldn’t believe them.Anita Milicic, Senior scientist, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/455412015-09-10T10:11:16Z2015-09-10T10:11:16ZExplainer: is it really OK to eat food that’s fallen on the floor?<figure><img src="https://images.theconversation.com/files/92461/original/image-20150819-10832-1czij1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's not still good.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/bloomgal/4138366729/in/photolist-7iGdfv-boA4g9-AFFP5-a5oF29-5YKRhG-e9UUjK-bVmsez-7dweuQ-pB4mjX-5LDsTX-7YCaVM-uFXbpz-64d4XB-brk3Fg-ekmNv-dYSEjP-4Yphek-dPuGGx-k8aN4B-nwevT8-cndZ2d-4F1syz-jXK7Up-nosimK-Kzrev-b2ZN7M-dxbUYm-dHtg4E-okSvMS-5tFwKC-2hcXZV-tEsAP-bKPeXv-8FUU8h-5LDsRZ-62ezFT-8Pq3AD-pHYeM-dTdy9W-iqRCAv-2vVkpu-dQ77Fo-5Ba7Ju-7CpQZS-5sDag8-ePrKer-p8fCj4-nvcygq-rKhJEY-6fSNKq">Sharon Sperry Bloom/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>When you drop a piece of food on the floor, is it really OK to eat if you pick up within five seconds? This urban food myth contends that if food spends just a few seconds on the floor, dirt and germs won’t have much of a chance to contaminate it. Research in my lab has focused on how food and food contact surfaces become contaminated, and we’ve done some work on this particular piece of wisdom. </p>
<p>While the “five-second rule” might not seem like the most pressing issue for food scientists to get to the bottom of, it’s still worth investigating food myths like this one because they shape our beliefs about when food is safe to eat.</p>
<p>So is five seconds on the floor the critical threshold that separates an edible morsel from a case of food poisoning? It’s a bit a more complicated than that. It depends on just how much bacteria can make it from floor to food in a few seconds and just how dirty the floor is. </p>
<h2>Where did the five-second rule come from?</h2>
<p>Wondering if food is still OK to eat after it’s been dropped on the floor (or anywhere else) is a pretty common experience. And it’s probably not a new one either. </p>
<p>A well-known, but inaccurate, story about Julia Child may have contributed to this food myth. Some viewers of her cooking show, The French Chef, insist they saw Child drop lamb (or a chicken or a turkey, depending on the version of the tale) on the floor and pick it up, with the advice that if they were alone in the kitchen, their guests would never know. </p>
<p>In fact it was a potato pancake, and it fell on the stovetop, not on the floor. Child put it back in the pan, <a href="https://www.youtube.com/watch?v=iR64GGyEv_o">saying</a> “But you can always pick it up and if you are alone in the kitchen, who is going to see?” But the misremembered story <a href="http://www.vanityfair.com/culture/2009/08/julia-child200908">persists</a>. </p>
<p>It’s harder to pin down the origins of the oft-quoted five-second rule, but a 2003 study reported that 70% of women and 56% of men surveyed were familiar with the five-second rule and that women were more likely than men to eat food that had been dropped on the floor. </p>
<p>So what does science tell us about what a few moments on the floor means for the safety of your food?</p>
<h2>Five seconds is all it takes</h2>
<p>The earliest research report on the five-second rule is attributed to <a href="http://news.aces.illinois.edu/news/if-you-drop-it-should-you-eat-it-scientists-weigh-5-second-rule">Jillian Clarke</a>, a high school student participating in a research apprenticeship at the University of Illinois. Clarke and her colleagues inoculated floor tiles with bacteria then placed food on the tiles for varying times. </p>
<p>They reported bacteria were transferred from the tile to gummy bears and cookies within five seconds, but didn’t report the specific amount of bacteria that made it from the tile to the food. </p>
<h2>But how much bacteria actually transfer in five seconds?</h2>
<p>In 2007, my lab at Clemson University <a href="http://dx.doi.org/10.1111/j.1365-2672.2006.03171.x">published a study</a> – the only peer-reviewed journal paper on this topic – in the Journal of Applied Microbiology. We wanted to know if the length of time food is in contact with a contaminated surface affected the rate of transfer of bacteria to the food.</p>
<p>To find out, we inoculated squares of tile, carpet or wood with Salmonella. Five minutes after that, we placed either bologna or bread on the surface for five, 30 or 60 seconds, and then measured the amount of bacteria transferred to the food. We repeated this exact protocol after the bacteria had been on the surface for two, four, eight and 24 hours.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92460/original/image-20150819-10863-81q7fh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Splat.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-270013301/stock-photo-bread-falls-buttered-side-down-isolated-on-white.html?src=DvoLl8puo7elEp0qsCdcuA-1-1">Toast via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<p>We found that the amount of bacteria transferred to either kind of food didn’t depend much on how long the food was in contact with the contaminated surface – whether for a few seconds or for a whole minute. The overall amount of bacteria on the surface mattered more, and this decreased over time after the initial inoculation. It looks like what’s at issue is less how long your food languishes on the floor and much more how infested with bacteria that patch of floor happens to be.</p>
<p>We also found that the kind of surface made a difference as well. Carpets, for instance, seem to be slightly better places to drop your food than wood or tile. When carpet was inoculated with Salmonella, less than 1% of the bacteria were transferred. But when the food was in contact with tile or wood, 48%-70% of bacteria transferred. </p>
<p>Last year, a study from from Aston University in the UK used nearly identical parameters to our study and <a href="http://www.aston.ac.uk/about/news/releases/2014/march/five-second-food-rule-does-exist/">found similar results</a> testing contact times of three and 30 seconds on similar surfaces. They also reported that 87% of people asked either would eat or have eaten food dropped on the floor. </p>
<h2>Should you eat food that’s fallen on the floor?</h2>
<p>From a food safety standpoint, if you have millions or more cells on a surface, 0.1% is still enough to make you sick. Also, certain types of bacteria are extremely virulent, and it takes only a small amount to make you sick. For example, 10 cells or less of an especially virulent strain of <em>E. coli</em> can cause severe illness and death in people with compromised immune systems. But the chance of these bacteria being on most surfaces is very low. </p>
<p>And it’s not just dropping food on the floor that can lead to bacterial contamination. Bacteria are carried by various “media,” which can include raw food, moist surfaces where bacteria has been left, our hands or skin and from coughing or sneezing. </p>
<p>Hands, foods and utensils can carry individual bacterial cells, colonies of cells or cells living in communities contained within a protective film that provide protection. These microscopic layers of deposits containing bacteria are known as biofilms and they are found on most surfaces and objects. </p>
<p>Biofilm communities can harbor bacteria longer and are very difficult to clean. Bacteria in these communities also have an enhanced resistance to sanitizers and antibiotics compared to bacteria living on their own. </p>
<p>So the next time you consider eating dropped food, the odds are in your favor that you can eat that morsel and not get sick. But in the rare chance that there is a microorganism that can make you sick on the exact spot where the food dropped, you can be fairly sure the bug is on the food you are about to put in your mouth.</p>
<p>Research (and common sense) tell us that the best thing to do is to keep your hands, utensils and other surfaces clean.</p><img src="https://counter.theconversation.com/content/45541/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Dawson receives funding from USDA - Bi-national Agricultural Research and Development. </span></em></p>A food scientist explains the nitty gritty of the five-second rule.Paul Dawson, Professor of Food Science, Clemson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/434812015-06-22T05:14:01Z2015-06-22T05:14:01ZAdult breast milk drinkers aren’t just wasting their money – they’re endangering their health<figure><img src="https://images.theconversation.com/files/85756/original/image-20150619-3349-11wl6po.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Human trade</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>“Breast is best”. So goes the message from the international and clinical guidance on what milk mothers should feed their babies. But it’s also more worryingly been adopted by a growing online community of adults wanting to buy and consume expressed breast milk for its perceived health benefits – or due to sexual fetishes.</p>
<p>Some online <a href="http://coloncancersupport.colonclub.com/viewtopic.php?f=1&t=15895&sid=93c3eb3aad6c140b94ee09f325447f6f&start=15">forums</a> suggest cancer patients should drink breast milk because it is supposedly easier to digest, better tolerated, and full of immune benefits, including immunoglobulin (a protein used by the immune system). Meanwhile, fitness and diet forums preach the nutritional, energy or recovery benefits of such milk, suggesting it can work as a supplement to workout or <a href="http://forum.bodybuilding.com/showthread.php?t=138482993">bulking regimes</a>. </p>
<p>A number of websites and online forums cater to those wishing to buy, sell and trade breast milk, alongside the use of more general social media platforms. This online marketplace allows women who are expressing milk to advertise with text and images, communicating details such as cost per ounce and a description of mother, milk and baby. Buyers can also advertise on such forums, detailing their own needs and volume requirements.</p>
<p>Individuals can then contact each other either to meet or arrange transport for the milk, which is often frozen or packed in dry ice, and shipped by express post or courier. Notably, the quality of packaging greatly varies, and <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4046749/">studies have shown</a> high levels of damage in transit.</p>
<p>The popularity of these sites varies by country depending on the availability of <a href="https://www.breastfeedingnetwork.org.uk/detailed-information/milk-banking/">government-subsidised milk banks</a>. But in the US, where regulated milk banks are costly, and the UK, where adult buyers are not catered for, online selling communities has been growing. New country specific websites are now being launched, including using .co.uk addresses. Such growth has led commentators to label online breast milk sale a “<a href="http://www.dailymail.co.uk/news/article-1389124/Pumping-profit-The-booming-black-market-breast-milk-earns-women-20k-year.html">booming market</a>” around the world. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/85758/original/image-20150619-3363-8tq72n.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">Pumped up.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Much of the milk sold on these sites does not meet the standards placed on milk banks, such as pasteurisation (which kills germs) or testing for disease or <a href="http://www.bmj.com/content/350/bmj.h1485">contamination</a>. Costs are often kept low by short cutting on storage, temperature, or shipping. A recent media investigation even found that online purchased milk had been delivered in a <a href="http://www.thesun.co.uk/sol/homepage/features/6456654/Breast-milk-bought-online-laced-with-toxic-bacteria.html">recycled gravy tin</a>. The result of such poor shipping and packaging is often high levels of <a href="http://pediatrics.aappublications.org/content/early/2013/10/16/peds.2013-1687.abstract">detectable bacteria growth</a>, including some bacteria that may lead to food-borne illness.</p>
<p>Tests on the milk have shown there is also a risk that it could <a href="http://pediatrics.aappublications.org/content/early/2013/10/16/peds.2013-1687.abstract">transmit communicable diseases</a>, including hepatitis B and C, HIV and syphilis. Often those women expressing milk may be not show any symptoms and be unaware that they even have a disease. This suggests it is possible they could unwittingly pass on medical conditions that could be especially problematic for those adults with weakened immune systems, such as cancer patients.</p>
<p>It is possible to pasteurise milk at home, something that is often practised by HIV-positive mothers in developing countries to reduce the risk of the virus being passed on to <a href="http://www.berkeley.edu/news/media/releases/2007/05/21_breastmilk.shtml">their children</a>. But these processes do not remove any contaminants and chemicals that make it into the milk. Claims that breast milk is a “clean eat” or “super food” that is “free from” potential harmful additives do not stand up to the science. Chemicals like caffeine, alcohol, prescription and illicit drugs and environment toxins can all make it into breast milk through <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2809366/">the mother’s body</a>.</p>
<p>As such, buyers are not just paying a jacked-up price for something that does not offer them more of a nutritional benefit than a diverse, balanced diet. (For example, breast milk is <a href="http://www.ncbi.nlm.nih.gov/pubmed/392766">lower in protein</a> than some other milks, contrary to the advice often given on online forums.) They may also may be <a href="http://jrs.sagepub.com/content/108/6/208.full">risking their health</a>. This is especially true when breast milk is used as a sole source of nutrition - as a small number of forums recommend - or to replace healthy balanced meals in conjunction with intense periods of exercise.</p>
<p>As such, education and healthcare professionals need to start issuing relevant and accurate advice. Dispelling the myths that are circulated online that are driving this trade, especially by and to vulnerable and sick adults, must be a priority. And health organisations and governments should hold a crucial role in such a campaign.</p><img src="https://counter.theconversation.com/content/43481/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Those buying and selling human breast milk online could be spreading disease without reaping any of the supposed health benefits.Sarah Steele, Queen Mary University of LondonAndreas Freitag, Research Fellow, National Clinical Guideline CentreLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/380842015-03-19T09:35:03Z2015-03-19T09:35:03ZThe media fuels vaccination myths – by trying to correct them<figure><img src="https://images.theconversation.com/files/75282/original/image-20150318-2471-1espt1r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Studies have shown that mentioning misinformation – even in the process of combating it – can cause it to stick in listeners' minds.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-132025811/stock-photo-conference-meeting-microphones-and-doctor.html?src=dt_last_search-3">from www.shutterstock.com</a></span></figcaption></figure><p>In recent years, misinformation about vaccines has discouraged parents from having their children vaccinated, which puts their own children – as well as their neighbors’ children – at risk. </p>
<p>In response, many doctors, scientists and journalists have worked together in an attempt to correct false beliefs about vaccination. For example, earlier this month, Jimmy Kimmel invited <a href="https://www.youtube.com/watch?v=QgpfNScEd3M">real doctors</a> to school his audience on the dangers of non-vaccination. </p>
<p>Yet research has shown that common correction strategies frequently backfire. Not only do these strategies increase the acceptance of misinformation, but they can also spread it to new audiences. While Kimmel’s entertaining approach avoided most of these pitfalls, other media outlets aren’t often that lucky.</p>
<h2>Familiarity equated with veracity</h2>
<p>To assess whether something is <a href="https://www.researchgate.net/publication/273704855_Metacognition">likely to be true</a>, people often rely on how often they’ve heard an opinion. If many people believe it, the thinking goes that there’s probably some truth to it. </p>
<p>Unfortunately, we’re bad at tracking what we hear and where we hear it from, and instead rely on a message’s familiarity. The more we hear something, the more familiar it feels, but we quickly forget the context (for example, whether or not we were assured something was true or false). As time passes, all that remains is the feeling that we “heard something like this before,” which we then interpret as evidence that it’s probably true. </p>
<p>When it comes to false information, every repetition increases its familiarity; for this reason, it’s a bad idea to repeat inaccurate information in the act of correcting it. Yet repeating falsehoods is a key element of articles like <a href="http://www.cbsnews.com/pictures/10-deadly-myths-about-childhood-vaccines/11/">“10 Deadly Myths about Childhood Vaccines”</a> or <a href="http://www.huffingtonpost.com/2015/02/05/anti-vaccine-arguments-analyzed-explained_n_6607026.html">“6 Dangerous Anti-Vaccine Arguments Analyzed, Explained and Shutdown”</a>. </p>
<p>Indeed, controlled experiments show that even serious news analyses that confront myths with facts backfire as time passes. In <a href="https://www.researchgate.net/publication/23547213_How_Warnings_about_False_Claims_Become_Recommendations">some studies</a>, we showed participants a series of statements and told them that some were true (“aspirin can damage tooth enamel”) and some were false (“corn chips contain twice as much fat as potato chips”). </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=794&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=794&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=794&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=998&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=998&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75116/original/image-20150317-22300-1cqkgoa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=998&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We absorb all information – true or false. And as time passes, we tend to equate familiarity with the truth.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?page=3&use_local_boost=1&version=llv1&country_code=US&searchterm=sponge&orientation=vertical&tracking_id=XPHiR0hqT9P_l6ZFwQ1nnw&thumb_size=mosaic&safesearch=1&search_language=en&search_type=keyword_search&inline=57826516">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>When we tested people immediately after, they made few errors. But when we tested them three days later, many had forgotten which statements were true and which were false. Instead, they relied on whether the statement felt familiar (“seems as if I heard something like this before”). In fact, after three days, the more times we had told participants a statement was false, the more likely they were to believe it was true. Because repetition increases familiarity, repeated <em>warnings</em> can actually morph into recommendations. </p>
<h2>One (repetitive) voice a chorus</h2>
<p>Just as social consensus can make any idea seem true, a <a href="https://www.researchgate.net/publication/273704855_Metacognition">lack of consensus</a> can call truth into question. People consider disagreement an indicator that the truth is unknown – that either side may be right. It doesn’t matter if there’s only a vocal minority; what matters is the sheer fact that there’s any disagreement at all. A single, repetitive voice can act as a chorus.</p>
<p>In <a href="http://www-personal.umich.edu/%7Esmgarcia/pubs/repeatedvoice.pdf">some experiments</a>, hearing an argument three times from the same person was almost as effective in persuading people that there is broad support for an opinion as hearing the message from three different people. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=801&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=801&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=801&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1006&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1006&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75113/original/image-20150317-22271-qyzm56.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1006&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Repetitive voices are effective in relaying messages. Maybe there’s a method to the madness of nagging…</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-222092377/stock-photo-mother-questioning-teenage-daughter-about-pregnancy-test.html?src=pd-same_artist-222092551-6HuHLf33I_bcE-G4n_CTEQ-2">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>An opinion, then, can be perceived as widely shared, even if it’s only heard, over and over, from the same person. This gives repetitive voices a big advantage, and as the vaccination discussions illustrate, a few persistent voices can shed doubt on the overwhelming consensus of 99% of medical professionals. Correction attempts should not provide an additional platform for further repetition.</p>
<p>Repetitions are particularly problematic when the disagreement is presented in overly polite terms. We often hear that the infamous vaccination study by Andrew Wakefield was “<a href="http://www.cnn.com/2015/02/04/us/5-vaccine-myths/">discredited</a>.” But this word is often interpreted as merely meaning “there are also contradictory findings.” It fails to convey that the original report was found to be fraudulent and based on fake data, and its author was stripped of his professional license. The credibility of a source is important, and readers can’t properly evaluate a source when the media withholds factual information about fraud, or softens it to “discredited” or “controversial.”</p>
<h2>Media can make misinformation memorable</h2>
<p>Misinformation is often presented with anecdotes, which are easy to understand, evoke vivid pictures in our minds, and are particularly likely to stick. This gives anecdotes the <a href="http://mdm.sagepub.com/content/31/5/742.short">power to override hard facts</a>, like statistics and scientific evidence. A vivid example about a single case of a vaccination’s apparent side-effects – complete with quotes from a worried parent – can then make it difficult for readers to reconcile the anecdote with statistical evidence intended to combat it. Worse, as time passes, the anecdote will remain memorable, while the statistics will be forgotten.</p>
<p>Misinformation is also more likely to stick when it’s accompanied by photographs. Even when the pictures have no evidence-based value and are merely intended to draw attention to an article, they can influence people’s beliefs. For example, in <a href="https://www.researchgate.net/publication/230623669_Nonprobative_photographs_(or_words_inflate_truthiness)%20participants%20were%20more%20likely%20to%20believe%20a%20false%20claim%20(such%20as" title="Magnesium is the liquid metal inside a thermometer">one study</a> when it appeared beside a photo of a thermometer. </p>
<p>Photos make claims <em>feel</em> true – not because they provide factual evidence, but because they make it easier for readers to imagine the claim. In a recent <a href="http://www.cbsnews.com/pictures/10-deadly-myths-about-childhood-vaccines/2/">CBS report</a> about vaccines, a photo of a boy behind a glass window may make it easier to imagine unfounded claims about autism. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=737&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=737&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=737&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=927&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=927&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75119/original/image-20150317-22288-1t0cr3i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=927&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s best to focus on promoting the scientifically proven benefits of vaccines, rather than getting sucked into debating vaccination myths.</span>
<span class="attribution"><a class="source" href="http://upload.wikimedia.org/wikipedia/commons/b/b8/Polio_vaccine_poster.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>In short, media reports that intend to correct false information can have the unfortunate effect of <em>increasing</em> its acceptance. Using anecdotes and images makes false information easier to imagine – and by highlighting disagreement, they distort the amount of consensus that actually exists. </p>
<p>It’s better to be a repetitive voice that highlights the facts, rather than one that draws attention to falsehoods. Ultimately, readers, viewers and listeners are better served by receiving correct information about the benefits of vaccination and the risks of non-vaccination in an easy-to-process format that makes accurate information feel familiar, credible and true.</p><img src="https://counter.theconversation.com/content/38084/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Norbert Schwarz received funding on related research from the National Institute of Aging. </span></em></p><p class="fine-print"><em><span>Eryn Newman received funding on related research from the Marsden Fund, Royal Society of New Zealand.</span></em></p>Studies show that the more familiar we become with false information, the more likely we are to later remember it as fact.Norbert Schwarz, Provost Professor of Psychology and Marketing and co-director of the Dornsife Mind & Society Center, USC Dornsife College of Letters, Arts and SciencesEryn Newman, Research Fellow, Dornsife Mind & Society Center, USC Dornsife College of Letters, Arts and SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/136622013-05-13T04:35:04Z2013-05-13T04:35:04ZMonday’s medical myth: flatlining patients can be shocked back to life<figure><img src="https://images.theconversation.com/files/23497/original/sgxyrj39-1368158231.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Like much of what we see on TV, this one’s a myth.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>Beep….beep……….beep……….beeeeeeeeeeeeeeeeeeeeeeeeep.</p>
<p>“We’re losing him. Out of my way, nurse!”</p>
<p>The quick-thinking young doctor charges the defibrillator paddles and places them on the chest of the lifeless patient, whose cardiac monitor is showing a straight green line. The patient gets a huge dose of electricity; his back arches and his limp body lifts up off the bed with the shock.</p>
<p>Seconds pass, then the familiar, comforting waveform appears on the monitor. The patient begins to stir, and is soon sitting up enjoying the healing properties of hospital sandwiches and a cup of tea. </p>
<p>You’ve probably seen this flatlining scene a million times on TV and films. Heck, they even <a href="http://www.imdb.com/title/tt0099582/">named a Kevin Bacon film</a> after it! It’s thrilling, compelling – and completely wrong. </p>
<p>To understand why this myth is so egregious, we need a quick background briefing on cardiac arrest. </p>
<p>The heart’s electrical system controls the organ’s ability to pump blood to the rest of the body. If the flow of this electricity becomes disorganised or the heart muscle stops responding normally, the regular pumping action is lost. Blood stops flowing and the body tissues have to cope with the sudden lack of oxygen supply. This is known as cardiac arrest. </p>
<p>We can see the various electrical wave patterns of the heart in cardiac arrest using an <a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Electrocardiogram">electrocardiogram</a> or ECG. There are four main rhythms you might see during a cardiac arrest:</p>
<ol>
<li><a href="http://www.wisegeek.com/what-is-pulseless-ventricular-tachycardia.htm">Pulseless ventricular tachycardia</a> (VT) is a very rapid and inefficient heart rhythm. The heart is beating so quickly that it can’t fill properly between beats. Circulation therefore drops rapidly to dangerously low levels.</li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=168&fit=crop&dpr=1 600w, https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=168&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=168&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=211&fit=crop&dpr=1 754w, https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=211&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/23450/original/b6bgj4bd-1368101325.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=211&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">VT is a rapid rhythm which doesn’t allow the heart to fill.</span>
<span class="attribution"><span class="source">ECGPedia.org</span></span>
</figcaption>
</figure>
<ol>
<li><a href="http://www.nlm.nih.gov/medlineplus/ency/article/007200.htm">Ventricular fibrillation</a> (VF) is basically chaotic, unco-ordinated contractions of the heart muscle. Picture a heart quivering like a bowl of meaty jelly, unable to summon a proper contraction to send the blood on its way.</li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=134&fit=crop&dpr=1 600w, https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=134&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=134&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=169&fit=crop&dpr=1 754w, https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=169&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/23451/original/q9cmbnt4-1368101389.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=169&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">VF is perhaps the most ‘survivable’ cardiac arrest cause.</span>
<span class="attribution"><span class="source">ECGPedia.org</span></span>
</figcaption>
</figure>
<ol>
<li><a href="http://emedicine.medscape.com/article/161080-overview">Pulseless electrical activity</a> (PEA) is where the heart rhythm appears normal on the ECG but the electrical activity is not producing any movement of the heart muscle. The lights are on, physiologically speaking, but nobody is home.</li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=85&fit=crop&dpr=1 600w, https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=85&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=85&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=106&fit=crop&dpr=1 754w, https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=106&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/23453/original/wx6t9hyv-1368102068.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=106&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 normal-looking ECG trace can belie a life-threatening condition in PEA.</span>
<span class="attribution"><span class="source">acls-algorithms.com</span></span>
</figcaption>
</figure>
<ol>
<li><a href="http://en.wikipedia.org/wiki/Asystole">Asystole</a> (aka flatline) is the complete absence of any detectable electrical activity of the heart muscle. It appears as a flat line on the monitors. Clearly this is the worst type of cardiac arrest and there’s little chance of coming back from it.</li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=199&fit=crop&dpr=1 600w, https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=199&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=199&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=250&fit=crop&dpr=1 754w, https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=250&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/23452/original/5t747hsc-1368101564.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=250&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 period of asystole follows some more normal beats.</span>
<span class="attribution"><span class="source">Wikipedia.com</span></span>
</figcaption>
</figure>
<p>These four ECG findings are classified into “shockable” and “non-shockable” rhythms, depending on whether they respond to the electrical current of the defibrillator. </p>
<p>Pulseless ventricular tachycardia and ventricular fibrillation (1 and 2) are shockable, largely because they tend to be caused by the electrical activity of the heart being thrown out of whack, and not by the heart muscle itself being badly damaged. </p>
<p>Hitting the heart muscle with a big dose of electrical energy acts a bit like hitting Ctrl-Alt-Delete on your computer (or Alt-Command-Esc for the Mac users). A single shock will cause nearly half of cases to revert to a more normal rhythm with restoration of circulation if given within a few minutes of onset.</p>
<p>Pulseless electrical activity and asystole or flatlining (3 and 4), in contrast, are non-shockable, so they don’t respond to defibrillation. These rhythms indicate that the heart muscle itself is dysfunctional; it has stopped listening to the orders to contract. The causes are hard to reverse and survival rates are very low. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=729&fit=crop&dpr=1 600w, https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=729&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=729&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=916&fit=crop&dpr=1 754w, https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=916&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/23507/original/83mjpsqx-1368163590.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=916&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">If you’ve flatlined, a shock is the last thing you need.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p>The treatment of choice for asystole is to continue [CPR](http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Cardiopulmonary_resuscitation_(CPR) (cardiopulmonary resuscitation) and give a whacking great dose of adrenaline. In fact, if you stop CPR to give an inappropriate shock, the patient’s outlook is <a href="http://www.resus.org.au/policy/guidelines/section_11/electrical_therapy_for_aals.htm">even more dire</a>. </p>
<p>But unlike the famous overdose scene in <a href="http://www.imdb.com/title/tt0110912/">Pulp Fiction</a> might suggest, there seems to be no survival advantage and quite considerable extra risk of giving it directly into the heart. (I’m also ignoring the fact that adrenaline would be useless for a heroin overdose.)</p>
<p>So next time you see that ominous flat line appearing on the monitor, and hear the heroic physician shout “clear” while busting out the paddles, you can join the exasperated ranks of those in the know, and try not to let reality ruin this most dramatic of TV tropes for you.</p>
<p><em><strong>This is the 100th medical myth and the last in the series. <a href="https://theconversation.com/topics/medical-myths">Click here</a> to see the other myths we’ve busted over the past two years.</strong></em></p><img src="https://counter.theconversation.com/content/13662/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Vagg 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>Beep….beep……….beep……….beeeeeeeeeeeeeeeeeeeeeeeeep. “We’re losing him. Out of my way, nurse!” The quick-thinking young doctor charges the defibrillator paddles and places them on the chest of the lifeless…Michael Vagg, Clinical Senior Lecturer at Deakin University School of Medicine & Pain Specialist, Barwon HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/136612013-05-06T04:38:11Z2013-05-06T04:38:11ZMonday’s medical myth: feed a cold, starve a fever<figure><img src="https://images.theconversation.com/files/23215/original/k9swc9pn-1367804623.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Whether or not you are feeding a cold or starving it makes little difference to the biology of a common cold.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>This winter, most of us will catch a cold. Our kids will probably catch at least two or three. We all know you are supposed to feed a cold and starve a fever. But does it really make any difference if they eat or not? </p>
<p>This proverb appears to have become popular in the nineteenth century. However, <a href="http://wiki.answers.com/Q/Should_you_feed_a_fever_or_starve_a_cold">dozens of websites</a> attribute the phrase back to the fourteenth century and Geoffrey Chaucer’s <a href="http://en.wikipedia.org/wiki/The_Canterbury_Tales">Canterbury Tales</a>. But no such phrase exists by Chaucer. It seems that everyone simply copied a story, without checking its original source. This is also how many medical myths start.</p>
<p>Colds are caused by viruses that infect the nose, sinuses and throat. But the unpleasant symptoms (blocked and runny nose, cough, sneezing, sore throat and headache) are <a href="http://www.ncbi.nlm.nih.gov/pubmed/16253889">largely triggered</a> by our body’s reaction to them, rather than any damage caused by these bugs.</p>
<p>The runny nose (often accompanied by sneezing) is caused by increased secretions from the glands in the nose and seepage of serum (the yellow cell-free part of blood) into the nose. </p>
<p>Progressively, white blood cells also find their way in and their presence causes the gunk coming out your nose to turn yellow or green, as these cells contain a green protein called myeloperoxidase. This change in colour is not caused by bacteria and does not mean you need to take antibiotics.</p>
<p>The blocked nose comes about as the large veins in your nose dilate to narrow the space available for air to flow, while at the same time, the volume of secretions are increased and their clearance is diminished, especially during the latter phases of a cold. </p>
<p>Curiously, one nostril is usually worse than the other, at any one time. And it’s not always the same one. In fact, which nasal passage is most blocked usually alternates from one to the other over a period of several hours. This so-called “<a href="http://www.ncbi.nlm.nih.gov/pubmed/8777979">nasal cycle</a>” is thought to be defensive response, possibly to keep one open while the other one is being pumped clean with protective fluids.</p>
<p>When you have a cold you often don’t feel much like eating anything. This is the result of chemicals released by your body to fight off infection also affecting your brain. These same chemicals can also make you feel irritable, lethargic, or just plain miserable. </p>
<p>But why should your brain want you to starve if you are ill? One reason may be that you don’t want to waste precious energy finding food that you could otherwise use in getting well? Of course this theory doesn’t wash if Mum has just made you <a href="https://theconversation.com/mondays-medical-myth-chicken-soup-cures-the-common-cold-1955">chicken soup</a>. But the modern brain still works much like a caveman’s did.</p>
<p>It has also been <a href="http://www.ncbi.nlm.nih.gov/pubmed/9468766">suggested</a> that not wanting to eat may be an important natural defence mechanism just like a <a href="http://www.ncbi.nlm.nih.gov/pubmed/22518930">fever</a>, which helps your immune system fight off infections. </p>
<p>In fact, if you <a href="http://ajcn.nutrition.org/content/32/3/593.abstract">force-feed mice during an infection</a> they are actually more likely to die than if they only eat what they feel like. </p>
<p>These facts have led to the idea that there may have been a semantic shift in the idiom. What we think of as “feed a cold, starve a fever” may originally have been “fede a cold starb o’feber” (fede = “stoke [a fire]”, starb = “die”, feber = “fever”) or “stoke the inflammation of an infection and you die”. </p>
<p>But while starving (in the short term) can keep a feverish mouse alive, this may have little relevance to an innocuous cold. </p>
<p>Most times grown-ups get a cold they don’t even get a temperature. Adults generally save fevers for bugs they’ve never seen before or severe infections, like influenza.
So you have a sore throat and a runny nose, but no fever or cough from the beginning, you’re probably just <a href="http://www.ncbi.nlm.nih.gov/pubmed/11088084">coming down with a common cold</a>. And so you may just as well feed (during) your cold, and save your starving for the fever. </p>
<p>For kids all bugs are new, so fevers are commonplace. This doesn’t mean they’re in any danger, but they’ll probably be more miserable than you are. </p>
<p>Whether or not you are feeding a cold or starving it makes little difference to the biology of a common cold. In the end, most colds are mercifully short lived and will peter out after a week or so, regardless. </p>
<p>But feeling healthy is much more than biology. When you’ve got a cold, food is essentially a comfort not a cure. And at these times we all could use some of that.</p><img src="https://counter.theconversation.com/content/13661/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca McNamara works for the Australian Research Council Centre of Excellence for the History of Emotions (Europe 1100-1800). She receives funding from the Australian Research Council. She works at the University of Sydney.</span></em></p><p class="fine-print"><em><span>Merlin Thomas 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>This winter, most of us will catch a cold. Our kids will probably catch at least two or three. We all know you are supposed to feed a cold and starve a fever. But does it really make any difference if…Merlin Thomas, Adjunct Professor of Preventive Medicine, Baker Heart and Diabetes InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/123732013-04-29T04:33:05Z2013-04-29T04:33:05ZMonday’s medical myth: you can think yourself better<figure><img src="https://images.theconversation.com/files/22877/original/dhs2mqr5-1366940194.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Being blindly and unrelentingly positive can be a burden to disease sufferers.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>Of all the cultural beliefs about health and illness that saturate the developed world, there is none so pervasive and deeply held as the idea that you can “battle” an illness by sheer force of will. </p>
<p>We admire people like AFL great <a href="http://en.wikipedia.org/wiki/Jim_Stynes">Jim Stynes</a> who show a brave and positive face to the public when confronted with a diagnosis of cancer, and somehow expect that a positive and determined mindset will help “overcome” the disease.</p>
<p>The underlying assumption here is that the mind and body are separate, a philosophical stance known as <a href="http://en.wikipedia.org/wiki/Dualism">dualism</a>.</p>
<p>In contrast, the scientific viewpoint is that the mind is caused by the brain. And all the neuroscientific data points this way.</p>
<p>So what, you may say. Even if the mind is caused by the brain, I can still consciously control my thoughts, and therefore I can influence things that go on in my body. This is quite true. </p>
<p>The next question, then, is whether there is evidence that optimism, positive thinking or learning to control your thoughts in some way will be enough to have a significant influence on any disease process. </p>
<p>It’s important to note that we’re not talking about quality of life. We’re interested in whether the actual course of a disease can be changed by purely mental effort. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/22885/original/mpv5mybs-1366940979.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">People who are optimistic are more likely to turn up to health appointments.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p>It’s common sense (and supported by mountains of positive studies) that sick people’s quality of life can be improved by having a positive outlook. </p>
<p>The consensus is that optimistic people turn up for their treatments more regularly and are more likely to find resourceful ways to get as much as they can out of their life with chronic illness. </p>
<p>Interestingly, <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273547/">pessimism may be more predictive of a bad outcome</a> than optimism is of a good one.</p>
<h2>What does the evidence say?</h2>
<p>The most comprehensive summary of the evidence on the subject of optimism and health is <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2941870/">this 2010 analysis of 83 studies </a>. Most of the studies take a cohort of subjects, score them by questionnaire to rate their levels of optimism, then sit back and watch what happens. </p>
<p>There are no control groups and no intervention to assess – the researchers just trawl the data for a correlation. If links are found, which isn’t always the case, a press release is issued and everyone marvels at how amazing the mind-body connection is. </p>
<p>Even if you find a robust and reproducible correlation, it doesn’t automatically follow that the link is causal. This is especially true if the study was not specifically set up to show the exact link you are looking for, with all bias and potential distractions removed. </p>
<p>I couldn’t find any studies that were set up to look at the effect of becoming more optimistic, or switching from pessimism to optimism, on a person’s disease. </p>
<p>But at least there’s no harm in being positive, right?</p>
<p>There’s not, but it’s possible that being blindly and unrelentingly positive can be a burden to disease sufferers. </p>
<p><a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2858803/">US researcher James Coyne</a> makes this point in his 2010 paper critiquing the positive psychology movement in cancer care. Coyne notes that enforcing a cultural expectation of positivity leaves many cancer patients scared that they’re reducing their chance of survival every time they feel scared, depressed or angry about their disease.</p>
<p>The paper quotes Dutch Olympian Maarten Van der Weijden, who rejected being identified with Lance Armstrong’s approach of “fighting” cancer:</p>
<blockquote>
<p>What he basically says is that it is your own fault when you don’t make it… You always hear those stories that you have to think positively, that you have to fight to survive. This can be a great burden for patients.</p>
</blockquote>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=453&fit=crop&dpr=1 600w, https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=453&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=453&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=569&fit=crop&dpr=1 754w, https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=569&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/22881/original/t64dr84h-1366940635.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=569&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t feel you need to be completely positive 100% of the time.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p>Cancer patients should be reassured that their disease was not caused by personality or emotional factors. Such a callous and false conclusion follows logically from a serious acceptance of the myth. It also would follow that cancer, multiple sclerosis, stroke or any other serious disease could be curable by addressing the emotional issues that supposedly underlie it. </p>
<p>So if there’s little evidence that just being an optimistic person is good for your health, there’s even less evidence that forcing yourself to use positive thinking can beat your disease. <a href="http://www.ncbi.nlm.nih.gov/pubmed/23390882">Positive psychology interventions</a> have only really been studied in mental health diseases such as depression and there seems to be no attempt to use thought to cure disease. </p>
<p>If faced with a serious illness, you’re likely to have a better quality of life if you have good social supports and avoid giving in to complete pessimism. Nobody can tell you the perfect formula to deal with the impact of a serious diagnosis. </p>
<p>But don’t believe those who tell you your illness is your fault somehow, or that you wouldn’t have it if you’d somehow been a better person.</p>
<p>You don’t need to feel that you should be completely positive 100% of the time, because not only does that not happen, it’s not healthy either. Coping the best way you know how to is all you should be aiming to do.</p><img src="https://counter.theconversation.com/content/12373/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Vagg 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>Of all the cultural beliefs about health and illness that saturate the developed world, there is none so pervasive and deeply held as the idea that you can “battle” an illness by sheer force of will. We…Michael Vagg, Clinical Senior Lecturer at Deakin University School of Medicine & Pain Specialist, Barwon HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/128252013-04-22T04:33:14Z2013-04-22T04:33:14ZMonday’s medical myth: overweight people live longer<figure><img src="https://images.theconversation.com/files/22648/original/2q7fyjcc-1366345198.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There’s no need to temper our efforts to address the obesity epidemic just yet.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>We’ve long known that too much excess weight increases your likelihood of dying prematurely. Or does it? </p>
<p>A <a href="http://jama.jamanetwork.com/article.aspx?articleid=1555137">large review of the evidence</a> published in the Journal of the American Medical Association (JAMA) in January found that overweight people live longer than leaner people. </p>
<p>But don’t reach for the pie and chips just yet. </p>
<p>There is no denying that the high and rising prevalence of obesity and overweight is a major health problem. With 70% of men and 56% of women either <a href="http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/034947E844F25207CA257AA30014BDC7?opendocument">overweight or obese</a>, Australia is among the worst-affected countries in the world. </p>
<p>We commonly measure body size with <a href="https://theconversation.com/explainer-overweight-obese-bmi-what-does-it-all-mean-7011">body mass index</a>, or BMI: a person’s weight in kilograms divided by the square of their height in metres. It is a good average measure of the amount of fat a person has in their body, which is useful for classifying people in population studies.</p>
<p>The <a href="http://www.who.int/mediacentre/factsheets/fs311/en/">World Health Organization</a> (WHO) defines a “normal” BMI range as 18.5 to 24.9 and this corresponds to a weight of 49 to 65kg for Australian women of average height (1.62 m) and 58 to 77kg for men of average height (1.76 m).</p>
<p>Recent <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61766-8/fulltext">estimates</a> have shown for the first time that a high BMI is now responsible for the greatest burden of disease in Australia and New Zealand, ahead of smoking and high blood pressure. </p>
<p>But the challenges represented by the obesity epidemic have raised the question of what the ideal BMI is for life expectancy.</p>
<p>Two large and well-conducted studies <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)60318-4/fulltext">in the Lancet</a> and <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1000367">New England Journal of Medicine</a> examined this issue by gathering data on more than two million people who had their BMI calculated and were followed for their risk of dying over a defined time period. </p>
<p>The large numbers of participants and detailed individual data in these studies means the researchers were able to look at how small differences in BMI relate to the risk of death, accounting for a range of other factors known to influence this relationship, including illnesses that could potentially affect BMI.</p>
<p>Despite the diversity of populations covered by the studies, and the differences in methods, their findings are remarkably consistent: people with a BMI at the upper end of the WHO “normal” level (22.5 to 24.9) have the lowest death rates. </p>
<p>You can see this visually represented by the J-shaped curve in the graph below: as BMI goes up in increments of 2.5 above and below the 22.5-to-24.9 category, so do death rates.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=519&fit=crop&dpr=1 600w, https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=519&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=519&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=652&fit=crop&dpr=1 754w, https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=652&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/22660/original/z7pxc2z4-1366354522.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=652&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">Hypothetical data showing the risk of death by fine BMI categories</span></span>
</figcaption>
</figure>
<p>Why do people with a BMI at the upper end of the “normal” range have the lowest risk of death? </p>
<p>People with BMIs above this optimal level have an increased risk of dying, especially from heart disease, most likely due to increases in blood pressure, cholesterol levels and diabetes caused by excess body fat. They also have an increased risk of dying of cancer. </p>
<p>People with BMI levels below the optimal level also have increased death rates, particularly from respiratory diseases (such as chronic bronchitis) and cancer. The increased risk of death in the people with lower BMIs may also be because chronic illness has caused them to lose weight.</p>
<p>So with this evidence in mind, how does the JAMA paper reach such a different conclusion?</p>
<p>It comes down to the way the data from each of the studies have been collated and presented. </p>
<p>The JAMA review used broad classifications for underweight, normal weight, overweight, and obese and very obese, rather than the 2.5 increments of BMI. People with a BMI of 18.5 to 24.9 were included in the “normal weight” category; we can see from the graph above that this broad category includes people with the lowest risk of death, combined with people with a higher risk of death. </p>
<p>The “normal weight” category was then used as the comparison group for the studies, and has an average risk of death that is higher than the risk in the broad “overweight” category. </p>
<p>This skews the optimal weight finding and changes the shape of the curve, from J-shaped to tick-shaped.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=538&fit=crop&dpr=1 600w, https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=538&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=538&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=676&fit=crop&dpr=1 754w, https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=676&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/22661/original/nn3gdr4q-1366354523.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=676&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">Hypothetical data showing the risk of death by broad BMI categories </span></span>
</figcaption>
</figure>
<p>The result? One that suggests being overweight makes you live longer.</p>
<p>There are varying reasons why the researchers might have used these broad groups, including the fact that many studies are too small to be able to present statistically reliable results according to finer gradations in BMI.</p>
<p>The bottom line is that too much fat is bad for your health and increases your risk of dying prematurely. We still have a long way to go in our fight against obesity and, if anything, we need to redouble, not reduce, our efforts.</p><img src="https://counter.theconversation.com/content/12825/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Banks receives research funding from the National Health and Medical Research Council and the Australian Primary Health Care Research Institute.</span></em></p><p class="fine-print"><em><span>Rosemary Korda receives funding from NHMRC and ARC</span></em></p><p class="fine-print"><em><span>Grace Joshy 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’ve long known that too much excess weight increases your likelihood of dying prematurely. Or does it? A large review of the evidence published in the Journal of the American Medical Association (JAMA…Emily Banks, Scientific Director of the 45 and Up Study, Sax InstituteGrace Joshy, Research Fellow, National Centre for Epidemiology and Population Health, Australian National UniversityRosemary Korda, Research Fellow, National Centre for Epidemiology and Population Health, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/128962013-04-15T04:55:33Z2013-04-15T04:55:33ZMonday’s medical myth: you can control the sex of your baby<figure><img src="https://images.theconversation.com/files/22415/original/kh36kxw2-1365987793.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Timing sex around ovulation doesn’t change the odds of having a boy or girl.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>Despite most parents ultimately just wishing for a healthy baby, there are many cultural and social factors that can drive the desire for a baby of a particular sex.</p>
<p>The medical technology for sex selection of embryos has existed in Australia for many years, but such an option is only available for medical reasons, such as sex-linked chromosomal disorder.</p>
<p>This leaves parents who do have a gender preference looking for natural ways of predetermining the sex of their baby.</p>
<p>In the 1960s, the idea that timing sex around ovulation can tip the odds in favour of a girl or a boy was popularised by Shettles and Rorvik in the best-selling book <a href="http://www.amazon.com/How-Choose-Sex-Your-Baby/dp/038548562X">How to Choose the Sex of Your Baby</a>.</p>
<p>Alongside thinking about the pH status of the reproductive tract, Shettles’ idea was that Y sperm (leading to male babies) swim faster than X sperm (leading to female babies), therefore if sex is timed close to ovulation they will arrive at the egg first. </p>
<p>However, Y sperm live fast and die young. If sex occurs a number of days before ovulation, the Y sperm die off before they reach the egg, maximising the chances for X sperm to achieve fertilisation.</p>
<p>Leaving aside the quandary raised by conceiving opposite-sex fraternal twins via this method, what does the science say on whether timing sex can result in a shift in the gender ratio?</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/4412107">Two studies in the 1970s</a> found very small shifts, with sex close to ovulation more likely to result in girls and sex on either side of ovulation more likely to result in boys. While rejecting Shettles’ theory, these studies did find some influence of timing (albeit small).</p>
<p>Since then, the <a href="http://www.ncbi.nlm.nih.gov/pubmed/21987941">evidence has been mixed</a>, but leans towards <a href="http://www.ncbi.nlm.nih.gov/pubmed/9647580">disputing any effect</a> of timing on sex selection. Perhaps the most <a href="http://www.ncbi.nlm.nih.gov/pubmed/7477165">high profile study</a>, published by American epidemiologist Allen Wilcox, found no evidence to suggest that the timing of sex around ovulation led to a significant change in the sex ratio of resulting babies. </p>
<p>If anything, again they found some minor support contradictory to Shettles’ theory, with girls slightly more common when sex and ovulation were close together. </p>
<p>If timing sex around ovulation doesn’t necessarily change the odds of having a boy or girl, what else might?</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/10885189">Some studies suggest</a> that male conceptions are favoured in the midst of wars and conflicts. An interesting finding, given it’s a time when male mortality rates are high. </p>
<p>Contradicting this, <a href="http://www.ncbi.nlm.nih.gov/pubmed/22677147">other research</a> finds that extreme stress can lead to more female births. The cause of this is unknown but may be related to the increased fragility of Y sperm during stressful times or general hormonal changes that favour females when times are tough.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/22429/original/t9gxwfk4-1365991468.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">One study found that starting your day with cereal might tip the scales towards a boy. But another found hig-calcium diets are more likely to give you a girl.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/18430648">More research</a> has focused on maternal diet pre-conception to predict changes in the sex ratio. Mothers who ate cereal for breakfast were more likely to have boys in one study. Another <a href="http://www.ncbi.nlm.nih.gov/pubmed/21051285">found</a> that a low-salt, high-calcium diet favoured girls.</p>
<p>I was ecstatic to find that a respected Swedish pregnancy researcher conducted a <a href="http://www.ncbi.nlm.nih.gov/pubmed/20618730">scientific study</a> of the accuracy of the much-googled Chinese lunar calendar sex-prediction method, based on an ancient chart “buried in a tomb for 700 years” but conveniently now <a href="http://www.babycenter.com/chinese-gender-predictor">available online</a>. </p>
<p>Alas, planning your conception based on your Chinese lunar age and the month of conception turns out to be no more accurate than flipping a coin. </p>
<p>Perhaps the most interesting study I’ve come across on this topic is one examining the offspring of the 2009 Forbes 400 Richest Americans list. </p>
<p>In <a href="http://www.ncbi.nlm.nih.gov/pubmed/23437389">this study of billionaires</a> (Bill Gates is at the top), men who inherited their money (heirs) were more likely to have sons than both self-made billionaires and the general population. </p>
<p>Heiresses were more likely to have female children than heirs, self-made billionaires and the general population. There were too few female self-made billionaires (just three) to be included.</p>
<p>Harking back to <a href="http://www.ncbi.nlm.nih.gov/pubmed/4682135">evolutionary theory</a> where higher parental resources lead to more male births, the author suggested that wealth without stress led to sons. He theorised that self-made billionaires were under more stress than heirs, plus due to the years required for empire building, they may have children prior to achieving their wealth. </p>
<p>So, scheduling sex to coincide with ovulation may not give you the little Mary-Jane or Thomas you were looking for. Moving to a war zone or starting your day with Special K might tip the scales towards Thomas, but if the war zone is stressful or you add too much high-calcium milk to that cereal, you’re sending the odds back towards Mary-Jane.</p>
<p>Chances are, the moment you hold your new baby for the first time, it won’t matter anyway.</p><img src="https://counter.theconversation.com/content/12896/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monique Robinson receives funding from the National Health and Medical Research Council (NHMRC).</span></em></p>Despite most parents ultimately just wishing for a healthy baby, there are many cultural and social factors that can drive the desire for a baby of a particular sex. The medical technology for sex selection…Monique Robinson, Associate Principal Investigator, Telethon Institute for Child Health Research, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/125002013-04-08T04:38:38Z2013-04-08T04:38:38ZMonday’s medical myth: yoghurt cures thrush<figure><img src="https://images.theconversation.com/files/22032/original/xbt3rz6g-1365030426.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Forget yoghurt, go to the chemist for an effective treatment for thrush.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p><a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Thrush">Vaginal thrush</a>, or “vulvovaginal candidiasis” is a common condition, with around three-quarters of women experiencing an episode in their lifetime. </p>
<p>Many readers may be familiar with the unpleasant symptoms of vaginal thrush – vaginal itching and burning, “cottage cheese” discharge with a yeasty smell, inflammation of the vagina and vulva, and pain while passing urine or having sex.</p>
<p>Most cases of thrush are uncomplicated and are due to an overgrowth of a <a href="http://en.wikipedia.org/wiki/Yeast">yeast</a> called <a href="http://en.wikipedia.org/wiki/Candida_albicans"><em>Candida albicans</em></a>. It is normal for <em>Candida</em> to be present in small numbers in the bowel, mouth, skin and <a href="http://www.health.sa.gov.au/pehs/ygw/candidiasisvulvovaginal-pehs-sahealth-2009.pdf">vagina</a>.</p>
<p>Reasons why there may be an overgrowth of <em>Candida</em> include: </p>
<ul>
<li>hormonal changes, such as pregnancy or starting on the oral contraceptive pill </li>
<li>diabetes </li>
<li>suppression of the immune system, such as HIV infection or chemotherapy for cancer</li>
<li>antibiotic treatment </li>
</ul>
<p>In a <a href="http://www.mja.com.au/journal/2003/179/1/not-thrush-again-womens-experience-post-antibiotic-vulvovaginitis">survey of Australian women</a> in general practice waiting rooms, a third reported experiencing thrush after antibiotics at some stage. Conceptually, antibiotics can kill bacteria that normally live in the vagina while <em>Candida</em>, a <a href="http://www.differencebetween.net/science/nature/difference-between-fungi-and-bacteria/">fungus</a> not a bacteria, tends to be unaffected. With less competition, the <em>Candida</em> can overgrow, leading to the symptoms of thrush.</p>
<p>This leads us to yoghurt. A quick <a href="http://www.google.com.au/#hl=en&q=yoghurt+and+vaginal+thrush">Google search</a> reveals links to websites giving interesting and varied health advice. But the basic rationale is consistent: yoghurt is effective because it contains “good bacteria”, <em>Lactobacillus</em>. The idea is that in using yoghurt (by eating it, and/or by applying it directly to the vagina and vulva) the “good” bacteria will <a href="http://ezinearticles.com/?Cure-Your-Vaginal-Thrush-With-Yogurt&id=2785588">help fight off</a> the “bad” <em>Candida</em>.</p>
<p>There is some biologic plausibility in this idea, though there is more than a smattering of <a href="http://www.skepdic.com/sympathetic.html">sympathetic magic</a> with how it is portrayed. However, the medical establishment shouldn’t be too smug – medical treatments for “<a href="http://archive.org/stream/mercksmanualofma00newy#page/180/mode/2up">vaginitis</a>” a century ago was positively barbaric! </p>
<p>A number of highly unpleasant astringent chemicals were recommended (though curiously, <a href="http://en.wikipedia.org/wiki/Boric_acid">boric acid</a> has stood the test of time and is still used for types of complicated or recurrent vaginal thrush).</p>
<p>As many as 40% of the women in the <a href="http://www.mja.com.au/journal/2003/179/1/not-thrush-again-womens-experience-post-antibiotic-vulvovaginitis">aforementioned survey</a> who had experienced vaginal thrush tried using yoghurt to cure or prevent thrush. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/22033/original/kvdzmnfn-1365030694.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">A third of women surveyed experienced thrush after taking antibiotics.</span>
<span class="attribution"><span class="source">Flickr/threeze</span></span>
</figcaption>
</figure>
<h2>So what is the evidence?</h2>
<p>It is important to recognise that there is a relative paucity of clinical evidence. A <a href="http://annals.org/article.aspx?articleid=705341">small (and flawed) trial from 1992</a> did seem to find that eating yoghurt helped, but neither yoghurt nor probiotic suppositories were demonstrated to decrease the recurrence of vaginal thrush in subsequent <a href="http://www.jfponline.com/Pages.asp?AID=10514">randomised controlled trials</a>.</p>
<p>An Australian <a href="http://www.bmj.com/content/329/7465/548">randomised placebo-controlled trial</a> testing to see whether oral or vaginal lactobacillus can help prevent thrush after antibiotics was similarly disappointing – neither appeared to be effective, though the author remarked that <a href="http://www.abc.net.au/health/talkinghealth/factbuster/stories/2008/10/14/2379507.htm">some women find</a> that “yoghurt has a cool soothing effect” and this might be a reason to use it.</p>
<p>In terms of recommended treatments, there are now effective therapies that are available without prescription at community pharmacies, including once-only treatments. These treatments are antifungal medications that target <em>Candida</em>. </p>
<p>For the typical acute and uncomplicated types of vaginal thrush, these treatments are effective at least 80% of the time. If they don’t, it’s time to see your regular general practitioner.</p><img src="https://counter.theconversation.com/content/12500/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Tam is a community general practitioner and consults with patients who have vaginal thrush. 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>Vaginal thrush, or “vulvovaginal candidiasis” is a common condition, with around three-quarters of women experiencing an episode in their lifetime. Many readers may be familiar with the unpleasant symptoms…Michael Tam, Lecturer in Primary Care and General Practitioner, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/108342013-03-31T21:13:40Z2013-03-31T21:13:40ZMonday’s medical myth: you lose most heat through your head<figure><img src="https://images.theconversation.com/files/20686/original/v5s6v2jv-1361926190.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You're no more likely to lose heat from your head than other parts of your body – except your hands and feet.</span> <span class="attribution"><span class="source">Taylor Mackenzie</span></span></figcaption></figure><p>As the weather starts to cool down and winter clothes enter rotation in our wardrobes, some peculiar combinations emerge: shorts and scarves; thongs and jackets; T-shirts and beanies. The last is often explained with an old saying: you lose most of your head through your head. But, in fact, scientists know this to be untrue.</p>
<p>Firstly, let’s go back to the basics of heat exchange.</p>
<p>Human heat exchange is dictated by a combination of physical principles, variations in body shape and size, and physiological control mechanisms such as altered skin blood flow, shivering and sweating. These interactions maintain a stable deep-body temperature, which is typically just below 37°C. </p>
<p>While <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(00)01021-7/abstract">survivable extremes</a> of 13.7°C and 46.5°C have been reported, you’re likely to feel miserable and unwell when this temperature drops below 35°C or rises above 40°C.</p>
<h2>Physical principles</h2>
<p>Looking beyond the body, heat is exchanged between all objects via dry pathways (radiation, convection, conduction) and through the evaporation of moisture. </p>
<p>For dry pathways, thermal energy moves from hotter to cooler regions, with its exchange rate depending on the temperature difference between these objects. </p>
<p>For evaporative cooling, water molecules leave moist surfaces to enter less humid air, taking heat with them. </p>
<p>These are the first principles of heat exchange.</p>
<h2>Body shape and size</h2>
<p>Heat is likely to be lost more rapidly from larger surfaces. Nevertheless, large masses have greater thermal stability, and resist rapid and significant changes in temperature. Thus, the interaction between surface area and mass provides another first principle: the temperature change of any object is dictated by the ratio of its surface area to its mass.</p>
<p>So a wafer-thin rectangular prism losses heat remarkably quickly, while a sphere, which has the smallest surface area to volume ratio of any object, provides the greatest resistance to heat loss. The relatively spherical shape of the human head, therefore, leads us to challenge the heat-loss myth on the basis of first-principles science.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/21712/original/j284wpzx-1364188435.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 toco toucan’s beak allows the bird to quickly cool down.</span>
<span class="attribution"><span class="source">Flickr/Brent</span></span>
</figcaption>
</figure>
<p>But we can’t ignore the physiological control of skin blood flow, as this is how heat is transported to the skin for dissipation, and sweating, which facilitates heat loss when the air is hotter than the skin.</p>
<p>There are many examples of how natural selection led to physiological changes to support temperature regulation. Take the toco toucan: the large surface area of this bird’s bill, in combination with its blood supply, enables <a href="http://www.sciencemag.org/content/325/5939/468.full">very efficient heat dissipation</a>. The same applies to elephant ears. </p>
<p>In humans, the closest equivalents are the <a href="http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1201&context=hbspapers">hands and feet</a>.</p>
<h2>Physiological control</h2>
<p>The head is not an ideal radiator, even though it has many blood vessels close to its surface, since its skin blood flow <a href="http://www.ncbi.nlm.nih.gov/pubmed/8493876">does not vary significantly</a> when one is either resting comfortably or dramatically cooled. Even when someone has a <a href="http://www.extremephysiolmed.com/content/2/1/4">dangerously high temperature</a>, head skin blood flow increases much less than that of the <a href="http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1201&context=hbspapers">hands and feet</a> for the same heating stimulus. </p>
<p>Plus most heads have about 50% hair coverage, which traps air and insulates against heat exchange. Although (sadly) not all heads conform with this generalisation.</p>
<p>The head is not great for evaporative cooling either. While the forehead is the <a href="http://www.extremephysiolmed.com/content/2/1/4">most prolific</a> sweat secretion site per unit area when we’re resting, sweating from sites inside the hairline occurs at <a href="http://www.ncbi.nlm.nih.gov/pubmed/18157675">half this rate</a>. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=901&fit=crop&dpr=1 600w, https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=901&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=901&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1132&fit=crop&dpr=1 754w, https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1132&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/21730/original/yg7gs3jf-1364253063.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1132&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Gloves and socks will help keep you warm.</span>
<span class="attribution"><span class="source">K Hatanaka</span></span>
</figcaption>
</figure>
<p>In fact, the head represents <a href="http://www.ncbi.nlm.nih.gov/pubmed/19900761">only about 7%</a> of the body surface area, so its contribution to whole-body evaporative cooling at rest is only 10%, and less than that of the hand, back, thigh and lower leg. While this heat loss can triple during exercise, it still accounts for <a href="http://www.extremephysiolmed.com/content/2/1/4">only 13%</a> of total evaporation.</p>
<p>So it would seem that even though the temperature of the head makes it well suited to losing heat, neither its geometry nor its physiological responses to heating or cooling make it a critical site for heat loss. </p>
<p>Covering your head is no more effective at keeping you warm than covering most other body regions. In other words, you’re no more likely to lose heat from your head than other parts of your body – except your hands and feet. So wearing gloves and socks is your best bet.</p><img src="https://counter.theconversation.com/content/10834/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nigel Taylor receives funding from various Government organisations, including the Australian Defence Force, Fire & Rescue New South Wales and the National Medical & Health Research Council.</span></em></p>As the weather starts to cool down and winter clothes enter rotation in our wardrobes, some peculiar combinations emerge: shorts and scarves; thongs and jackets; T-shirts and beanies. The last is often…Nigel Taylor, Associate Professor of Thermal Physiology, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/126972013-03-25T03:26:34Z2013-03-25T03:26:34ZMonday’s medical myth: crossing your legs is bad for your health<figure><img src="https://images.theconversation.com/files/21060/original/bbvnmwph-1362627974.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Infertility, high blood pressure, varicose viens and back pain have been attributed to leg crossing – but what does the evidence say?</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>Almost everyone crosses their legs, whether it’s conscious or unconscious, for custom, for comfort, for effect, to stop your legs splaying, to take pressure off a foot, or for no reason at all. But is it bad for your health?</p>
<p>Your doctor will often tell you to uncross your legs because <a href="http://www.ncbi.nlm.nih.gov/pubmed/10450120">blood pressure rises slightly</a> when you cross your legs at the knee. Some people are even able to use this increase in blood pressure to their advantage by crossing their legs to <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=leg+crossed+syncope">prevent an impending faint</a>. But while high blood pressure is bad for your health, there is no evidence that leg crossing contributes to the condition. </p>
<p><a href="http://www.womenshealth.gov/publications/our-publications/fact-sheet/varicose-spider-veins.cfm">Varicose veins</a> are another reason we’re told not to cross our legs. These unsightly, swollen blood vessels occur as a result of damage to the small valves that normally keep the blood moving in one direction: straight back to the heart. In those with varicose veins, some blood refluxes out into the small veins on the surface which subsequently balloon under the pressure.</p>
<p>Varicose veins are more common in women, especially those who have had (many) children and with advancing age. Crossing your legs may draw attention to varicose veins but it’s not their cause. </p>
<p>Leg crossing has also been suggested (mostly by chiropractors) to lead to bad posture and its downstream effects on the back, hip and pelvis. Certainly, those with back and hip problems may experience discomfort when crossing their legs. Try it yourself and you may feel the muscles of your back tightening a little. If those same areas were otherwise inflamed it’s easy to understand why leg crossing could seem problematic.</p>
<p>But what is cause and effect is unclear, and it may be that sitting in bad chairs for long periods is more to blame than what we are doing with our legs to cope. There is also <a href="http://www.ncbi.nlm.nih.gov/pubmed/857">some evidence</a> that leg crossing could reduce strain on abdominal muscles and improve joint stability, which could actually be beneficial in some cases.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=990&fit=crop&dpr=1 600w, https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=990&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=990&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1244&fit=crop&dpr=1 754w, https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1244&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/21465/original/qynv9sjk-1363743825.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1244&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 some evidence to suggest leg crossing could reduce strain on abdominal muscles.</span>
<span class="attribution"><span class="source">Flickr/joejukes</span></span>
</figcaption>
</figure>
<p>Prolonged compression of the (<a href="http://en.wikipedia.org/wiki/Peroneal_nerve">peroneal</a>) nerve that runs along the outer part of your knee can sometimes make your foot “fall asleep” after crossing your legs. This is not dangerous or a sign of impending paralysis, and after a few seconds things will usually return to normal. In some people, it takes a bit longer (minutes). </p>
<p>In a <a href="http://www.ncbi.nlm.nih.gov/pubmed/18145967">very small number</a>, prolonged and/or habitual leg crossing may damage the nerve, and probably has more to do with a special susceptibility rather than the behaviour itself.</p>
<p>In men, crossing your legs while wearing trousers raises the temperature of the groin. This has led to <a href="http://www.forbes.com/sites/alicegwalton/2011/07/21/the-low-down-down-there-male-fertility/">the suggestion</a> that would-be fathers should not cross their legs (or for the same reason wear tight fitting underwear and balance a laptop). </p>
<p>But you’d probably have to leave them crossed for many hours every day to have any effect on your sperm count. And besides, most men tend to rotate their hip out when crossing their legs for long periods to make a “figure four” and thus alleviate any unwanted tension.</p>
<p>Leg crossing has long been linked to morality and etiquette. In some countries and cultures leg crossing is looked on as casual, disrespectful, and altogether lower class. For the same reasons, many orthodox religions frown upon leg crossing in church. And what’s good for the soul should be good for the feet as well. </p>
<p>But piety and respect aside, you’re unlikely to do any long-lasting harm simply by crossing your legs while sitting. The problem is really caused by sitting in the first place. Don’t make yourself comfortable – get up and <a href="https://theconversation.com/office-workers-its-time-to-beat-the-bulge-and-quit-the-sit-5557">get moving</a>.</p><img src="https://counter.theconversation.com/content/12697/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Merlin Thomas 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>Almost everyone crosses their legs, whether it’s conscious or unconscious, for custom, for comfort, for effect, to stop your legs splaying, to take pressure off a foot, or for no reason at all. But is…Merlin Thomas, Adjunct Professor of Preventive Medicine, Baker Heart and Diabetes InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/122712013-03-18T03:29:01Z2013-03-18T03:29:01ZMonday’s medical myth: women forget the pain of childbirth<figure><img src="https://images.theconversation.com/files/21335/original/22kxyj5j-1363557720.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You may not forget the pain, but if you’re lucky, the end will justify the means.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>In an evolutionary sense, memory of pain serves an important purpose. Pain indicates a threat to our safety or our life, and human survival depends on us avoiding things that are going to kill us.</p>
<p>Historically childbirth has been both incredibly painful and associated with a high risk of maternal death. So how come humans kept lining up to do it over and over again? It makes sense that somewhere along the line a theory was posited that, unlike other pain, women just don’t remember the pain of childbirth. If they did, women might never go back there and thereby threaten the survival of the species.</p>
<p>The myth that women are biologically programmed to forget the pain of childbirth is also fostered by the language we use to describe the euphoria and relief of delivering a healthy baby. At the moment of holding a child for the first time, women often report that the pain of labour has all but been forgotten. It hasn’t really been forgotten, but the happiness and reward colour the memory of the preceding pain. This is known as the <a href="http://www.ncbi.nlm.nih.gov/pubmed/11251509">halo effect</a>.</p>
<p>Interestingly, while the science won’t back up the claim that women forget entirely, it <a href="http://www.ncbi.nlm.nih.gov/pubmed/19076128">does suggest</a> that over time, many women remember labour and birth pain as being less severe than they originally recalled. This relationship seems to hold mainly for women who reported moderate levels of pain.</p>
<p>At the extremes of pain, <a href="http://www.ncbi.nlm.nih.gov/pubmed/14992155">memories appear more constant</a>. Women who reported soon after the birth that their labour pain constituted “the worst pain imaginable” were mostly sticking to that opinion when questioned one year later. Same for the women who reported their birth as “pain-free”.</p>
<p>Pain is only one element of the overall birth experience, and other factors that contribute to how a birth is remembered include satisfaction with care-providers, choice of pain relief, level of medical intervention, complications, outcomes for the baby, and all sorts of personal factors. These elements <a href="http://www.ncbi.nlm.nih.gov/pubmed/19076128">may play a large role</a> in determining how pain is remembered.</p>
<p>When all those other aspects added up to a positive overall birth experience, women reported less pain at the time, and were more likely to lower their rating of the pain over time. When these aspects combined to produce a negative experience, women <a href="http://www.ncbi.nlm.nih.gov/pubmed/19076128">reported</a> more pain in childbirth and did not forget the intensity of that pain up to five years later.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/21341/original/5vg36t49-1363564462.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">Satisfaction with care-providers, choice of pain relief and the level of medical intervention can affect how pain is remembered.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p>It seems that with time comes more opportunity to process the birth and with that more distress at the way a negative experience played out. In fact, Australian data suggest that around 3-6% of women <a href="http://www.ncbi.nlm.nih.gov/pubmed/20059799">develop post-traumatic stress symptoms</a> after a negative birth experience. </p>
<p>Serious complications such as very preterm labour <a href="http://www.ncbi.nlm.nih.gov/pubmed/18403139">increase the risk</a> for a negative recollection of birth over time. There is no opportunity for a halo effect when a newborn in distress is rushed to the intensive care unit.</p>
<p>A slightly depressing finding for those who plan to be on first name terms with their anaesthetist during the birth is that even when pain relief is used, it may not lessen the memory of pain overall. <a href="http://www.ncbi.nlm.nih.gov/pubmed/19076128">One study</a> found that women who had epidural analgesia during labour remembered pain more intensely than women who didn’t. This pointed to “peak pain” memories for these women prior to the epidural, indicating pain isn’t evaluated on average across labour but instead particular moments stand out. </p>
<p>However a child is brought into the world, there are many health professionals who can talk to women about their fears and anxieties about pain or the experience as a whole. Being psychologically prepared may assist some women, particularly those having their first child or those who have had a negative experience in the past.</p>
<p>There are lots of options for pain control in childbirth and like everything with parenting, you need to know yourself (and your threshold for pain) and work out a plan with your care-provider that feels right for you. You may not forget the pain, but if you’re lucky, the end will justify the means.</p><img src="https://counter.theconversation.com/content/12271/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monique Robinson receives funding from Australian Rotary Health.</span></em></p>In an evolutionary sense, memory of pain serves an important purpose. Pain indicates a threat to our safety or our life, and human survival depends on us avoiding things that are going to kill us. Historically…Monique Robinson, Associate Principal Investigator, Telethon Institute for Child Health Research, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/126662013-03-11T03:36:21Z2013-03-11T03:36:21ZMonday’s medical myth: alcohol kills brain cells<figure><img src="https://images.theconversation.com/files/21050/original/ktg272y9-1362619082.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Booze won't kill your brain cells but it can still harm your brain.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>Do you ever wake up with a raging hangover and picture the row of brain cells that you suspect have have started to decay? Or wonder whether that final glass of wine was too much for those tiny cells, and pushed you over the line? </p>
<p>Well, it’s true that alcohol can indeed harm the brain in many ways. But directly killing off brain cells isn’t one of them. </p>
<p>The brain is made up of nerve cells (neurons) and <a href="http://www.scientificamerican.com/article.cfm?id=the-root-of-thought-what">glial cells</a>. These cells communicate with each other, sending signals from one part of the brain to the other, telling your body what to do. Brain cells enable us to learn, imagine, experience sensation, feel emotion and control our body’s movement. </p>
<p>Alcohol’s effects can be seen on our brain even after a few drinks, causing us to feel tipsy. But these symptoms are temporary and reversible. The <a href="http://www.nature.com/scientificamericanmind/journal/v23/n2/full/scientificamericanmind0512-10c.html">available evidence</a> suggests alcohol doesn’t kill brain cells directly. </p>
<p>There is <em>some</em> evidence that moderate drinking is linked to improved mental function. A 2005 Australian <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2005.01158.x/abstract;jsessionid=2C245A2DE969D4F79EF8B748BB93E9E5.d03t02">study</a> of 7,500 people in three age cohorts (early 20s, early 40s and early 60s) found moderate drinkers (up to 14 drinks for men and seven drinks for women per week) had better cognitive functioning than non-drinkers, occasional drinkers and heavy drinkers. </p>
<p>But there is also evidence that even moderate drinking may impair brain plasticity and cell production. <a href="http://www.sciencedirect.com/science/article/pii/S0306452212008457">Researchers</a> in the United States gave rats alcohol over a two-week period, to raise their alcohol blood concentration to about 0.08. While this level did not impair the rats’ motor skills or short-term learning, it impacted the brain’s ability to produce and retain new cells, reducing new brain cell production by almost 40%. Therefore, we need to protect our brains as best we can.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=542&fit=crop&dpr=1 600w, https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=542&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=542&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=682&fit=crop&dpr=1 754w, https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=682&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/21084/original/pq8tty3m-1362701945.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=682&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Even moderate drinking may impair brain plasticity.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p>Excessive alcohol undoubtedly <a href="http://www.nature.com/scientificamericanmind/journal/v23/n2/full/scientificamericanmind0512-10c.html">damages brain cells</a> and brain function. Heavy consumption over long periods can damage the connections between brain cells, even if the cells are not killed. It can also affect the way your body functions. Long-term drinking can cause brain atrophy or shrinkage, as seen in brain diseases such as stroke and Alzheimer’s disease.</p>
<p>There is debate about whether permanent brain damage is caused directly or indirectly.</p>
<p>We know, for example, that severe alcoholic liver disease has an indirect effect on the brain. When the liver is damaged, it’s no longer effective at processing toxins to make them harmless. As a result, poisonous toxins reach the brain, and may cause <a href="http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001347/">hepatic encephalopathy</a> (decline in brain function). This can result in changes to cognition and personality, sleep disruption and even coma and death.</p>
<p>Alcoholism is also associated with nutritional and absorptive deficiencies. A lack of Vitamin B1 (thiamine) causes brain disorders called <a href="http://www.nlm.nih.gov/medlineplus/ency/article/000771.htm">Wernicke’s ncephalopathy</a> (which manifests in confusion, unsteadiness, paralysis of eye movements) and <a href="http://www.nlm.nih.gov/medlineplus/ency/article/000771.htm">Korsakoff’s syndrome</a> (where patients lose their short-term memory and coordination).</p>
<p>So, how much alcohol is okay?</p>
<p>To reduce the lifetime risk of harm from alcohol-related disease or injury, the <a href="http://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/ds10-alcohol.pdf">National Health and Medical Research Council recommends</a> healthy adults drink no more than two standard drinks on any day. Drinking less frequently (such as weekly rather than daily) and drinking less on each occasion will reduce your lifetime risk.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=897&fit=crop&dpr=1 600w, https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=897&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=897&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1127&fit=crop&dpr=1 754w, https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1127&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/21083/original/n8jxzs9q-1362701492.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1127&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Health guidelines suggest men and women drink no more than two standard drinks a day.</span>
<span class="attribution"><span class="source">Image from shutterstock.com</span></span>
</figcaption>
</figure>
<p>To avoid alcohol-related injuries, adults shouldn’t drink more than four standard drinks on a single occasion. This applies to both sexes because while women become intoxicated with less alcohol, men tend to take more risks and experience more harmful effects. </p>
<p>For pregnant women and young people under the age of 18, the guidelines say not drinking is the safest option.</p>
<p>So while alcohol may not kill brain cells, if this myth encourages us to rethink that third beer or glass of wine, I won’t mind if it hangs around. </p><img src="https://counter.theconversation.com/content/12666/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nick Dorsch is a retired neurosurgeon and a board member of the Brain Foundation.</span></em></p>Do you ever wake up with a raging hangover and picture the row of brain cells that you suspect have have started to decay? Or wonder whether that final glass of wine was too much for those tiny cells…Nick Dorsch, Clinical Associate Professor, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/122982013-03-04T03:49:31Z2013-03-04T03:49:31ZMonday’s medical myth: no pain, no gain<figure><img src="https://images.theconversation.com/files/20794/original/phtvs7tz-1362104546.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Jane Fonda was wrong – you don't need to "feel the burn" to reap the benefits of exercise.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>The value of regular physical activity to a person’s well-being is unequivocal. But how much exercise do we need to maintain health, improve fitness or lose weight? And where is the line between healthy and harmful?</p>
<p>To maintain a healthy weight, <a href="https://www.eatforhealth.gov.au/sites/default/files/files/the_guidelines/n55a_australian_dietary_guidelines_summary_book.pdf">Australia’s dietary guidelines</a> recommend adults do at least 30 minutes of moderate intensity physical activity – such as brisk walking, social tennis or swimming – on most days. But if we want to lose weight, and don’t cut back on food and drink, we need to do more. </p>
<p>The <a href="http://www.acsm.org/about-acsm/media-room/news-releases/2011/08/01/acsm-issues-new-recommendations-on-quantity-and-quality-of-exercise">American College of Sports Medicine</a> agrees adults should get at least 150 minutes of exercise a week, though it explains this might be 20 to 60 minutes of vigorous exercise – which makes you huff and puff, such as jogging, aerobics, football and netball – three days a week. </p>
<p>The College guidelines <a href="http://www.acsm.org/about-acsm/media-room/news-releases/2011/08/01/acsm-issues-new-recommendations-on-quantity-and-quality-of-exercise">also prescribe</a> the quantity and and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal and neuromotor (or functional) fitness in healthy adults:</p>
<ul>
<li><p>For flexibility, adults should do stretching exercises at least two days a week, with each stretch being held for ten to 30 seconds, to the point of tightness or slight discomfort</p></li>
<li><p>For resistance training, adults should train each major muscle group two or three days a week </p></li>
<li><p>For cardiovascular fitness, people should gradually increase the time, frequency and intensity of their workout. </p></li>
</ul>
<p>The adage that if a little bit of exercise is good for me, then more should be better, still pervades the fitness industry. As does the “no pain, no gain” myth, which came to prominence in the early 1980s via Jane Fonda aerobic workout videos. Fonda would also urge viewers to “feel the burn” and exercise beyond the point of reasonable physical stress. These days the “no pain, no gain” motto is used to show that physical development is the result of training hard. </p>
<p>We often judge the efficacy of our workouts by our level of soreness the next day. This type of pain is called <a href="http://www.bmj.com/content/325/7362/468">delayed onset muscle soreness</a> or DOMS and occurs a day or two after exercise. It is most frequently felt when you begin a new exercise program, change your routine, or dramatically increase the duration or intensity of your workout. DOMS is a normal response to unusual exertion and is part of the body’s adaptation process that leads to increased strength or endurance as muscle recover and hypertrophy. </p>
<p>But while discomfort is natural if you push yourself, pain is the body’s protective mechanism, warning us to ease the intensity or protect an injured part of the body. Resisting this warning risks damaging tissue and may cause your body to over-compensate with other movements that can aggravate the injury and lengthen healing time. It’s also likely to reduce your motivation to continue exercising. </p>
<p>Pain during exercise can also indicate underlying health problems and should be seen as a signal to stop exercising and seek professional advice:</p>
<ul>
<li>Chest pain during exercise is a red flag for potential heart problems </li>
<li>Exercise-induced <a href="http://en.wikipedia.org/wiki/Bronchospasm">bronchospasm</a> (a sudden constriction of the bronchial muscles), even in non-asthmatics, may indicate an underlying respiratory problem</li>
<li>Joint pain may result from osteoarthritis or indicate meniscal (knee) injury, ligament or tendon microdamage.</li>
</ul>
<p>If you do find yourself sore after a tough workout or competition, try some low-impact aerobic exercises to maintain your blood flow during warm-down. Other remedies such as massage, ice baths and the RICE (rest, ice, compression, elevation) combination may also ease muscle soreness. </p>
<p>In terms of medication, non-steroidal anti-inflammatory drugs (such as aspirin, ibuprofen) can temporarily help reduce the effects of muscle soreness, though they won’t speed-up healing.</p>
<p>It’s certainly not easy building up your fitness or losing weight but the “no pain, no gain” motto is based less on the science of exercise physiology than on outdated sports psychology; it’s a recipe for injury. </p>
<p>When you feel pain during exercise, stop what you’re doing and take stock of how you’re feeling. If you think you can, try returning to the activity you were doing, but if the pain persists, then stop for good. </p><img src="https://counter.theconversation.com/content/12298/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Milburn 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 value of regular physical activity to a person’s well-being is unequivocal. But how much exercise do we need to maintain health, improve fitness or lose weight? And where is the line between healthy…Peter Milburn, Professor, School of Rehabilitation Sciences, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/121512013-02-25T03:30:15Z2013-02-25T03:30:15ZMonday’s medical myth: stress can turn hair grey overnight<figure><img src="https://images.theconversation.com/files/20478/original/86689vnw-1361414209.jpg?ixlib=rb-1.1.0&rect=0%2C37%2C1944%2C1201&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You may achieve your pigmentary potential a little ahead of schedule, but you can’t go grey overnight.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>The belief that nervous shock can cause you to go grey overnight (medically termed <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1806841/"><em>canities subita</em></a>) is one of those tales which could nearly be true. There are certainly cases in medical literature of <a href="http://www.ncbi.nlm.nih.gov/pubmed/22582919">rapid greying over quite short periods of time</a>. And reported cases <a href="http://www.ncbi.nlm.nih.gov/pubmed/1503208">go back to antiquity</a> including such legendary figures as Thomas More and Marie Antoinette. </p>
<p>The biology of the phenomenon suggests that a mixture of hormones and cognitive bias is responsible for the myth.</p>
<p>There is little doubt that <a href="http://www.ncbi.nlm.nih.gov/pubmed/16364026">plausible biological mechanisms</a> exist to account for emotional stress potentially affecting hair growth. What’s fascinating to me, as a pain specialist, is that several of the signalling proteins involved (such as <a href="http://en.wikipedia.org/wiki/Nerve_growth_factor">nerve growth factor</a> and <a href="http://en.wikipedia.org/wiki/Substance_P">substance P</a>) are the very same ones that operate in other nerves to create and regulate pain signals.</p>
<p>Human hair cycles between a growth phase (<a href="http://dermatology.about.com/od/hairanatomy/l/bldefanagen.htm">anagen</a>), a resting phase (<a href="http://dermatology.about.com/library/bldefcatagen.htm">catagen</a>) and a dormant phase (<a href="http://dermatology.about.com/od/glossary/g/telogen3.htm">telogen</a>). Pigment is produced by the hair follicle to colour the hair during the anagen phase while it is growing. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=856&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=856&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=856&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1075&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1075&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20480/original/zv87wcyr-1361416474.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1075&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Marie Antoinette’s hair may have turned grey, but it didn’t happen overnight.</span>
<span class="attribution"><span class="source">Joseph Ducreux</span></span>
</figcaption>
</figure>
<p>The length of the anagen phase varies according to your genes and certain hormonal levels. It can be anything between two years and eight years. When the follicle receives orders to end the anagen phase, it stops producing more hair and begins to prepare for telogen. Telogen phase lasts for between six and eighteen months at a time before heading back into anagen.</p>
<p>After ten or so of these cycles the follicle runs out of pigment and produces a hair with no colour at all. Despite its white colour, we insist on referring to these as “grey hairs” for some obscure linguistic reason. </p>
<p>Intense stress can cause large numbers of your follicles to hit telogen at around the same time, producing simultaneous loss of a large percentage of coloured hair. This phenomenon is known as <em><a href="http://emedicine.medscape.com/article/1071566-overview">telogen effluvium</a></em>. </p>
<p><em>Telogen effluvium</em> is often caused by drugs which affect the hormonal control of the hair cycle, including chemotherapy drugs and anti-<a href="https://theconversation.com/explainer-what-is-parkinsons-disease-698">Parkinson’s</a> drugs. </p>
<p>Interestingly, these hormonal signals have a less potent effect on non-coloured hair, so a person could conceivably lose large amounts of coloured hair, leaving behind mostly white hair. This <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002405/">could also happen</a> at a stressful time, such as the night before your execution. It can also happen due to auto-immunity (<em><a href="http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002421/">alopecia areata</a></em>) where the feral antibodies target pigment-producing follicles ahead of non-pigmented ones.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=527&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=527&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=527&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=662&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=662&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20470/original/b2974prt-1361403897.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=662&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Blame pigmentary potential, not the stress of being the leader of the Free World.</span>
<span class="attribution"><span class="source">U.S. Air Force</span></span>
</figcaption>
</figure>
<p>The problem for the myth is that none of this can happen as suddenly as overnight. </p>
<p>There are also plenty of good alternative explanations for these reports. In the case of Marie Antoinette, she was seen little in public in the couple of weeks before her execution, and would also have been deprived of her wigs and servants to dye her hair, if indeed that was one of her guilty secrets. </p>
<p>People such as President Obama, who go visibly greyer during a period of extreme stress over months or years, are usually at an age where many of their unfortunate follicles are on their last pigment cycle. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=605&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=605&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=605&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=760&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=760&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20471/original/t9q7r8s5-1361403962.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=760&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">What a difference four years can make.</span>
<span class="attribution"><span class="source">The White House</span></span>
</figcaption>
</figure>
<p>Confirmation bias means we remember those stressed people who look much greyer, but don’t remember those who go through such periods without visible greying. </p>
<p>We also tend to ignore those who grey early and don’t seem particularly stressed. That gets put down to genetics rather than stress.</p>
<p>So no matter how stressful your life may become, it might help to know that although you may achieve your pigmentary potential a little ahead of schedule, you can’t go grey overnight.</p><img src="https://counter.theconversation.com/content/12151/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Vagg 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 belief that nervous shock can cause you to go grey overnight (medically termed canities subita) is one of those tales which could nearly be true. There are certainly cases in medical literature of…Michael Vagg, Clinical Senior Lecturer at Deakin University School of Medicine & Pain Specialist, Barwon HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/116652013-02-18T03:30:09Z2013-02-18T03:30:09ZMonday’s medical myth: controlled crying damages babies’ brains<figure><img src="https://images.theconversation.com/files/20294/original/h2b5dv5s-1360904434.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Controlled crying is when parents respond to their infant’s cries and gently comfort them, then return at increasing time intervals.</span> <span class="attribution"><span class="source">Flickr/tea...</span></span></figcaption></figure><p>In my clinical work with pregnant and postnatal mums experiencing anxiety and mood disorders, few issues are reported as consistently as sleep deprivation. Parents who spend the first year of their child’s life (or longer) waking up regularly throughout the night to attend to their child are, not surprisingly, <a href="http://www.ncbi.nlm.nih.gov/pubmed/11389250">at a higher risk</a> for depression and anxiety.</p>
<p>It’s therefore understandable that parents want to know what can be done to help babies to sleep through the night. And with that interest comes strong opinions, best-selling books and even a “baby whisperer”, as it seems whispering is no longer just for horses.</p>
<p>In the midst of this clamour of advice is a good deal of controversy on a sleep technique for babies known as controlled crying. Advocates claim it saved their baby’s sleep and their sanity. <a href="http://www.pinkymckay.com/about-pinky">Critics liken it to</a> “normalised abuse” and claim it can cause lasting psychological damage.</p>
<p>We need to start where very few critiques on the topic have started – with a definition of what controlled crying is, and what it is not.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/22966034">Controlled crying</a> (also known as controlled comforting) is when parents respond to their infant’s cries and gently comfort them, then return at increasing time intervals to assist the infant to self-settle while knowing that the parent is still there. The key words there are <em>respond</em> and <em>return</em>.</p>
<p>The recommended implementation of such a technique is <a href="http://www.ncbi.nlm.nih.gov/pubmed/4064606">after six months</a> of age. By Piaget’s theory of <a href="http://en.wikipedia.org/wiki/Object_permanence">object permanence</a>, this is the developmental stage when babies understand that an object (in this case the parent) still exists even when it is out of sight.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=904&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=904&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=904&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1135&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1135&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20295/original/42grygp3-1360904851.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1135&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Controlled crying techniques should only be employed when babies are aged six months or above.</span>
<span class="attribution"><span class="source">Angel Kittiyachavalit</span></span>
</figcaption>
</figure>
<p>Controlled crying is not “extinction”. The extinction method is a dramatically-termed technique which refers to leaving a baby to “cry it out”. For example, when the infant cries at night, the parent shuts the door to the nursery and does not respond at all. The idea is that eventually the baby will understand that the parent is not returning and will self-settle.</p>
<p>In terms of controlled crying (not extinction), <a href="http://www.ncbi.nlm.nih.gov/pubmed/11991909">Australian researchers found</a> that when mothers of infants aged six to 12 months used one of two interventions (controlled crying and “camping out”, where parents remain in the room while the infant returns to sleep before quietly leaving), not only was there a significant improvement in infants’ sleep, there was also a significant reduction in maternal depressive symptoms compared with controls.</p>
<p>The research team <a href="http://www.ncbi.nlm.nih.gov/pubmed/22966034">followed up</a> these mothers and infants at the age of six years, and found no difference in emotional or behavioural problems, sleep problems, attachment, parenting styles or maternal mental health between intervention and control groups.</p>
<p>Despite it being clear that extinction techniques were not used in this study, there was considerable controversy about these findings. A <a href="http://www.bmj.com/content/324/7345/1062?tab=responses">letter to the British Medical Journal</a> (BMJ) where the original paper was published even compared the study to research conducted in Nazi Germany under Hitler.</p>
<p>More recently, critics of controlled crying such as <a href="http://www.pinkymckay.com/about-pinky">Pinky McKay</a> and <a href="http://www.margotsunderland.org/">Margot Sunderland</a> have drawn attention to the long-term ill effects of controlled crying. Ms McKay notes that babies who are left to cry are at risk of sensory deprivation and potentially long-lasting brain damage induced by early trauma, similar to what we know in psychological research as <a href="http://parentingaustralia.com.au/newborn/care/39-controlledcrying">learned helplessness</a>.</p>
<p>These critics are supported by a <a href="http://www.aaimhi.org/inewsfiles/controlled_crying.pdf">position paper</a> against the use of controlled crying from the Australian Association for Infant Mental Health (AAIMH); however, this position paper has not been updated in almost ten years and explicitly notes that its reference list does not include any studies on the impact of controlled crying on infants.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=906&fit=crop&dpr=1 600w, https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=906&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=906&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1139&fit=crop&dpr=1 754w, https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1139&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/20297/original/tg5gkcd3-1360905564.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1139&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Poor sleep increases new parents’ risk of developing depression and anxiety.</span>
<span class="attribution"><span class="source">Flickr/zzathras777</span></span>
</figcaption>
</figure>
<p>The evidence from both animal and human studies is <a href="http://www.americanscientist.org/issues/pub/the-deprived-human-brain/1">very clear</a> that severe stress such as emotional neglect and abuse in infancy does indeed induce long-lasting changes in the developing brain. And I can see the link between extinction techniques and emotional neglect.</p>
<p>But it’s extreme to compare controlled crying, where the parent <em>responds</em> and <em>returns</em>, to emotional neglect such as that suffered by infants raised in Romanian orphanages. This confusion between extinction and controlled crying appears to be at the heart of the criticisms.</p>
<p>At the end of the day (literally), each family needs to work out what the best technique is to get their infant to sleep. Techniques such as controlled crying and camping out might help some families, but others will be very uncomfortable at the idea of not responding immediately to their infant. </p>
<p>Every baby is different, and suggesting there is one magic solution that will work for all babies, or that what worked for them will work for everyone, is not only misleading, but also confusing and distressing for mothers desperately seeking an answer and some sleep.</p>
<p>There’s a wealth of mums, <a href="http://www.saveoursleep.com.au/aboutus/australianbabywhisperer.asp">whisperers</a>, <a href="http://www.carolinesangels.com.au/">angels</a>, and child health nurses out there - listen to their advice and work out the right solution for you and your family. </p><img src="https://counter.theconversation.com/content/11665/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monique Robinson receives funding from Australian Rotary Health.</span></em></p>In my clinical work with pregnant and postnatal mums experiencing anxiety and mood disorders, few issues are reported as consistently as sleep deprivation. Parents who spend the first year of their child’s…Monique Robinson, Associate Principal Investigator, Telethon Institute for Child Health Research, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.