tag:theconversation.com,2011:/us/topics/dha-11105/articlesDHA – The Conversation2017-09-07T11:18:31Ztag:theconversation.com,2011:article/835282017-09-07T11:18:31Z2017-09-07T11:18:31ZEating oily fish during pregnancy could prevent schizophrenia in the child, new study suggests<figure><img src="https://images.theconversation.com/files/185996/original/file-20170914-9015-18bc7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/450048262?src=K3CJAc8vRWnZPawTZ83wCw-1-21&size=medium_jpg">dangdumrong/Shutterstock</a></span></figcaption></figure><p>Mice that are deprived of an essential fatty acid, called docosahexaenoic acid (DHA), during pregnancy, are more likely to produce pups that display schizophrenia-like symptoms as adults, according to a <a href="https://www.nature.com/tp/journal/v7/n9/full/tp2017182a.html">new study</a> from Japan. </p>
<p>DHA is an essential fatty acid – “essential” because our bodies can’t produce it. It must be obtained from food. Oily fish, such as salmon and sardines, are good sources of dietary DHA. It is well understood that DHA plays a role in brain development. It is especially important during the last three months of pregnancy, and in the first two years of adolescence. </p>
<p>Studies have shown that babies fed on DHA-supplemented formula milk display higher visual acuity and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2757317/">problem-solving at 10 to 12 months</a>. In an animal study, rats deprived of DHA – resulting in a 50-80% reduction in DHA levels in the brain – were shown to have <a href="https://www.ncbi.nlm.nih.gov/pubmed/11080210">impaired learning and memory</a>. Conversely, dietary DHA supplementation has been shown to <a href="https://www.ncbi.nlm.nih.gov/pubmed/15672635">improve learning and memory</a> in brain damaged lab rats. </p>
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<p>In the Japanese study, conducted by researchers at the RIKEN Brain Science Institute in Tokyo, mice were fed on a diet free from DHA, prior to conception and up to the point the offspring had been weaned. The mouse pups were then given a standard diet, containing DHA, and tested at eight weeks, which roughly translates to human adolescence. </p>
<p>The cognitive function of the mice was assessed using standard mazes; they needed to find and remember the location of a food reward. And depression and motivation were assessed by monitoring the mice’s general activity and how quickly they avoided open spaces in special mazes (mice prefer enclosed spaces). </p>
<p>Mice born from mothers fed on a diet that excluded DHA showed significantly lower performance on the range of tests, compared with mothers fed on a standard diet. Consequently, these mice displayed schizophrenia-like symptoms including, impaired cognitive function, and reduced motivation; characteristic of the early stage of disorder. This led the study’s authors to suggest that getting enough DHA during pregnancy may protect against schizophrenia-like symptoms in the offspring. </p>
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<img alt="" src="https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=473&fit=crop&dpr=1 600w, https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=473&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=473&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=594&fit=crop&dpr=1 754w, https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=594&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/184976/original/file-20170906-18486-8fk3lp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=594&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Mice were tasked with locating a food reward.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/3142630?src=wHl8YjQcdfLtZKY_fRK4ig-1-5&size=medium_jpg">OZ photo/Shutterstock</a></span>
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<h2>The role of epigenetics</h2>
<p>The mechanisms underlying how diet can play such an important role in brain function and health are poorly understood. The dogma of genetics being entirely based on what we inherit, rather than the environment we are exposed to, has been questioned by scientists in recent years. The advent in understanding of the concept of <a href="https://www.whatisepigenetics.com/fundamentals/">epigenetics</a> has revolutionised the field of genetic science and provided a potential mechanism through which the environment exerts an influence on genes.</p>
<p>Under epigenetic modification, certain <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3107542/">mechanisms</a> can change the way a gene functions, or is expressed – without changing DNA itself – resulting in vastly different outcomes. These mechanisms are in turn activated by environmental factors, including <a href="https://www.ncbi.nlm.nih.gov/pubmed/22415078">diet</a>. </p>
<p>In the Japanese study, the researchers investigated the levels of two genes (<a href="http://www.sciencedirect.com/science/article/pii/S0301008208000464">Rxr and Ppar</a>), known to be associated with schizophrenia in humans. They found evidence that these genes had been modified by epigenetic factors, resulting in lower activity in the mice that displayed schizophrenia-like symptoms. </p>
<p>It’s very difficult to draw a direct comparison between evidence gained from studies in mice, to humans. However, the study identified similar low levels of the RxR and Ppar gene in hair follicle samples obtained from schizophrenic patients. This suggests that adequate levels of DHA in the maternal diet protects normal gene function, which in turn protects against expression of genes associated with schizophrenia. </p>
<p>Ultimately, given that epigenetic modifications to genes can also be passed on to future offspring, this study provides further evidence for the critical role dietary levels of DHA play in brain function and health. Also, given that epigenetic modifications to genes can be passed on, adequate maternal nutrition is not just essential to their offspring, but also to future generations.</p><img src="https://counter.theconversation.com/content/83528/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Mazzocchi-Jones receives funding from the Medical Research Council, and the Ramacoitti Foundation. He is also a Labour Party Borough (Newcastle-under-Lyme) and County Councillor (Staffordshire). </span></em></p>The offspring of mice who don’t get enough DHA during pregnancy are more likely to have pups that display schizophrenia-like symptoms.David Mazzocchi-Jones, Lecturer in Neuroscience, Keele UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/746972017-03-22T02:36:31Z2017-03-22T02:36:31ZYou can’t rely on fish oil supplements in pregnancy to make your children smarter<figure><img src="https://images.theconversation.com/files/161762/original/image-20170321-5377-76zr43.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The fatty acid DHA is crucial for fetal brain development in the last trimester of pregnancy. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/78880765?size=huge_jpg">from www.shutterstock.com </a></span></figcaption></figure><p>Fish oil supplements that contain DHA (the omega-3 fatty acid docosahexaenoic acid) are marketed to pregnant women as a way to support brain development. After all, who doesn’t want their child to be smart? </p>
<p>However most <a href="http://ajcn.nutrition.org/content/97/3/531">clinical trials</a> that have examined the impact of DHA on brain development are underpowered – that is, they don’t contain adequate subject numbers to draw reasonable conclusions – or have methodological limitations.</p>
<p>A large and robust trial of 500 South Australian mother-child pairs has just been completed. Women were given high-dose DHA or a vegetable oil placebo throughout the second half of pregnancy. Comprehensive assessments of child intelligence, language, behaviour and executive functions (complex high-order skills) at <a href="http://jamanetwork.com/journals/jama/fullarticle/186750">18 months</a>, <a href="http://jamanetwork.com/journals/jama/fullarticle/1866084">4 years</a> and now <a href="http://jamanetwork.com/journals/jama/article-abstract/2612605">7 years</a> have consistently shown no benefit of fish oil supplements.</p>
<p>It has taken more than 10 trials of DHA supplements in pregnancy with over 5,000 women to evaluate initial claims that fish oil can make kids smarter, but we finally have an answer: if you have a normal pregnancy and eat a varied diet, then they don’t.</p>
<h2>How did the focus on fish oils start?</h2>
<p>The link between fish oil and the brain began when it was discovered that the <a href="http://ajcn.nutrition.org/content/60/2/189.short">brain is rich</a> in the omega-3 fatty acid called DHA. Fish, and fish oil, is rich in DHA, although smaller amounts can also be found in egg yolk and the lean tissue of red meat. Once eaten, DHA is absorbed into the blood stream to be distributed to the body. The more DHA we eat, the higher the level of <a href="http://europepmc.org/abstract/med/8793415">DHA in our blood</a>. </p>
<p>This is important for the unborn baby, who receives DHA from mum’s blood. DHA is transferred from the mother to the baby by the placenta. Large amounts of DHA go to the baby’s brain, particularly in the last trimester when the brain undergoes a rapid growth spurt. The supply of DHA during this important period of brain development is crucial. Infants who are born preterm miss the placental supply of DHA and have <a href="http://www.sciencedirect.com/science/article/pii/S0022347605812478">lower levels in their brain</a>.</p>
<p>The idea that fish during pregnancy will make children smarter was supported by a <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(07)60277-3/abstract">2007 observational study</a> of seafood intake at 32 weeks pregnancy in over 5,000 UK women. Children up to three and a half years old were more likely to have lower motor, social and communication skill scores if mothers ate less than three portions of seafood a week. There was no association between seafood intake and IQ measured at 8 years, but women who ate less than three portions of seafood a week were more likely to have a child with a lower verbal IQ score.</p>
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<a href="https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=872&fit=crop&dpr=1 600w, https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=872&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=872&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1096&fit=crop&dpr=1 754w, https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1096&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/161764/original/image-20170321-5384-ttprfo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1096&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">Adequate amounts of fatty acids for fetal brain development are provided by eating fish such as salmon.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/111847235?src=7j0Mq244SSmxNPhxD426nQ-1-8&size=medium_jpg">from www.shutterstock.com</a></span>
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<p>Many interpreted these finding as showing benefits of eating fish during pregnancy for child brain development. Supplement manufacturers have used the finding to market benefits of fish oil, leading the general public to believe that DHA supplements for pregnant women are beneficial for brain development.</p>
<p>Experts were less convinced. Observational studies such as this don’t prove that eating fish will make a child smarter because of confounding factors that also influence child development. In this study, for example, women who ate less than three portions of seafood a week had lower levels of education, were more likely to be smokers and were less likely to have breastfed their child.</p>
<p>Only randomised controlled trials can prove cause and effect, because all confounding factors are evenly randomised between the treatment and placebo groups. Our trial was the first with a large sample and consistent assessments at important developmental periods with excellent follow-up rates. </p>
<h2>Do any supplements support brain development in pregnancy?</h2>
<p>Fish oil is not the only supplement once assumed to improve child brain development that has now been refuted due to lack of scientific evidence. Prenatal <a href="http://ajcn.nutrition.org/content/83/5/1112.long">iron</a> and <a href="http://ajcn.nutrition.org/content/early/2013/09/11/ajcn.113.065854">iodine</a> were both once considered beneficial, but have limited effectiveness when the mother is not deficient in these nutrients. Too few studies have investigated <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000230.pub5/full">zinc</a> or <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004905.pub4/full">multivitamins</a> during pregnancy for babies’ brains. </p>
<p>As with the fish oil studies, most of the women in these trials have had a varied diet and are unlikely be deficient in these nutrients or benefit from excess supply.</p>
<p>Certain groups of women, such as vegans or vegetarians may benefit from other supplements. </p>
<h2>Fish oils may be useful in other ways</h2>
<p>While DHA supplements may not make your baby smarter, there are suggestions of other possible benefits.</p>
<p>Several trials of DHA-rich fish oil during pregnancy have found a <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003402.pub2/full">slight increase</a> in the length of pregnancy in women taking the supplement. This has led to small decreases in the number of children born very preterm in these studies. While further studies are needed to prove this effect, DHA is one of the only interventions that has been identified with the potential to prevent preterm birth.</p>
<p>DHA is known to have a role in the immune response to inflammation and infection. A <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010085.pub2/full">review</a> of DHA supplements in pregnancy has found children with a high-risk of developing an allergy, such as if they have a close family member with an allergy, may be less likely to develop an allergy. </p>
<p>It’s worth noting here the dose of DHA used in these trials showing possible benefits is typically double-to-quadruple times the dose in off-the-shelf prenatal supplements. Further work is needed to prove these effects.</p>
<p>A healthy, varied diet is the best way to ensure all nutrient requirements are met. There is general consensus fish should be part of a healthy diet during pregnancy; it is an excellent source of DHA and other omega-3 fatty acids, protein and a variety of vitamins and minerals. </p>
<p>However, some (predatory) fish species such as shark and swordfish contain mercury, which is likely to be harmful to an unborn baby. <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/mercury-in-fish">Intake should be limited</a> to <a href="https://www.choosemyplate.gov/moms-food-safety-fish">species that are safe</a> for pregnant women to eat, such as salmon and tinned light or skipjack (not albacore) tuna.</p><img src="https://counter.theconversation.com/content/74697/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jacqueline Gould receives funding from the Women's and Children's Hospital Foundation. </span></em></p><p class="fine-print"><em><span>Maria Makrides receives funding from NHMRC for this study and for her salary. Maria has previously served on advisory boards for the Nestle Nutrition Institute and Fonterra, for which honoraria were paid to her employing institution. </span></em></p>Fish oil capsules are marketed as prenatal supplements to improve brain development in children. But now top quality evidence suggests they won’t make any difference in women eating a balanced diet.Jacqueline Gould, Research Fellow, South Australian Health & Medical Research InstituteMaria Makrides, Professor and Theme Leader, Healthy Mothers, Babies and Children , South Australian Health & Medical Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/693212017-01-04T03:36:49Z2017-01-04T03:36:49ZDoes a healthy diet have to come at a hefty price?<figure><img src="https://images.theconversation.com/files/148618/original/image-20161205-19401-gz9lg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Eating healthfully adds up quickly.</span> <span class="attribution"><span class="source">Fruits and veg via ww.shutterstock.com</span></span></figcaption></figure><p>Imagine you’re in the aisle of your favorite grocery store, bombarded with hundreds of the latest and greatest products on the market. After grabbing a box of your favorite pasta off the shelf, you notice a new organic version of the spaghetti sauce you usually buy. Strikingly, you notice that the price is <a href="https://mic.com/articles/144522/organic-food-expensive#.goBlOVkpk">at almost a 50 percent premium</a> compared to what your usual sauce costs. </p>
<p>Here we go again, you think: You have to empty your wallet to buy the “healthy” stuff. </p>
<p>If this describes how you think about the relationship between food health and price, you’re not alone. This belief is so pervasive that tips on how to eat <a href="http://www.foodnetwork.com/healthy/packages/healthy-eating-on-a-budget.html">healthy on a budget</a> are everywhere, implying that most consumers think this is a truly difficult task. Who hasn’t heard Whole Foods’ nickname, “<a href="http://www.bloomberg.com/news/articles/2016-05-18/whole-foods-seeks-to-shed-whole-paycheck-rap-with-new-format">Whole Paycheck</a>,” or seen incredibly cheap pricing on <a href="http://time.com/money/4208250/fast-food-deals-winners-losers/">unhealthy fast food</a>? </p>
<p>Measuring the relationship between health and price of food is in fact <a href="http://www.ers.usda.gov/webdocs/publications/eib96/19982_eib96_reportsummary_1_.pdf">difficult</a> as it can be evaluated in a variety of ways, from price per calorie to price per average portion. </p>
<p>So how pervasive is the view that “healthy = expensive” and why do consumers think this way? </p>
<p>In a <a href="http://dx.doi.org/10.1093/jcr/ucw078">series of studies</a> recently published in the <a href="http://www.ejcr.org/">Journal of Consumer Research</a>, we found that consumers do tend to believe that healthy foods are in fact more expensive. While this may actually hold true in only <a href="http://www.foxnews.com/leisure/2012/03/11/10-reasons-organic-food-is-so-expensive/">some product categories</a>, we discovered that many consumers tend to believe this relationship holds across all categories, regardless of the evidence.</p>
<h2>Consumers and lay theories</h2>
<p>Consumers appear to have a lay theory, or an intuition, that healthy foods are more expensive. </p>
<p>Discussions around <a href="http://americannutritionassociation.org/newsletter/usda-defines-food-deserts">food deserts</a> – low-income geographical areas with <a href="http://www.usnews.com/news/articles/2015/12/07/millions-of-food-desert-dwellers-struggle-to-get-fresh-groceries">limited access to affordable nutritious foods</a> – also suggest that healthy foods are indeed more expensive than unhealthy ones.</p>
<p>The marketplace and the media appear to have taught most U.S. consumers to expect foods with special health properties to command a premium price. While this is the case in some instances (for example, the USDA notes a price premium for many <a href="http://www.ers.usda.gov/topics/natural-resources-environment/organic-agriculture/organic-market-overview/">organic foods</a>), in other cases a general positive relationship between price and healthiness <a href="http://articles.latimes.com/2012/may/16/news/la-heb-healthy-cheap-food-usda-20120516">may not exist</a>.</p>
<p>A <a href="http://www.encyclopedia.com/social-sciences/applied-and-social-sciences-magazines/lay-theories">lay theory</a>, in psychology, is the term for a nonexpert’s belief about how the world works. We can have lay theories about how everything from <a href="https://www.jstor.org/stable/25674423?seq=1#page_scan_tab_contents">self-control</a> to <a href="http://nymag.com/news/features/27840/index1.html">intelligence</a> works. And these lay theories influence how we behave. </p>
<p>Consumers also have lay theories about food: for example, believing that <a href="https://www.psychologytoday.com/blog/sapient-nature/201104/the-unhealthy-tasty-intuition-are-you-under-its-subconscious-influence">unhealthy foods are tastier</a>, regardless of whether this is objectively true.</p>
<p>In our research, we document a new lay theory consumers have about food: that healthy foods are more expensive. In other words, unlike other research exploring whether there is a <a href="http://www.tandfonline.com/doi/pdf/10.1080/19320248.2015.1095144">true relationship between food health and price</a>, we were interested in understanding how this belief (regardless of whether it is objectively true) influences our food choices. Across five studies, we showed that even in food categories where there is no relation between price and health, the healthy = expensive intuition affects how consumers make decisions about food.</p>
<h2>How a food’s price equates to health</h2>
<p>Diving deeper into understanding what’s going on in the mind of the consumer, we wanted to know: Do higher price points drive consumers to think of something as healthier? Or do cues about healthiness lead consumers to believe that the price is higher? </p>
<p>In our studies, we found that the intuition seems to operate in both directions. That is, in our first study, we showed that when consumers were presented with price information only, perceptions of the healthiness of a breakfast bar varied with the price: higher price = healthier, lower price = less healthy. Similarly, when given a nutrition grade of an “A-,” the sort of summary analyses provided by various websites, including <a href="http://www.caloriecount.com">CalorieCount.com</a>, the breakfast bar was estimated as more expensive than when the same bar was graded as a “C.”</p>
<p>In another study, consumers were asked to choose the healthier of two similar chicken wraps. When the “Roasted Chicken Wrap” was priced at US$8.95 versus a “Chicken Balsamic Wrap” for $6.95, people chose roasted over balsamic. But when the prices were flipped, so were the choices. That is, people were actively choosing the more expensive option because they believed it was healthier.</p>
<p>Another study showed that food products running counter to the healthy = expensive intuition – that is, a product claiming to be healthy but offered at a less expensive than average price for the product category – led consumers to seek out more supporting evidence before they bought into a generic health claim. Specifically, study participants presented with a $0.99 protein bar (after being told that the average price for protein bars is $2 per bar) chose to view, on average, more than three online reviews before rating how likely they would be to buy the product themselves compared with two reviews when the protein bar had a $4 price tag. </p>
<p>It simply took more convincing when the price seems too good to be true for stated health claims.</p>
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<img alt="" src="https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=332&fit=crop&dpr=1 600w, https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=332&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=332&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=417&fit=crop&dpr=1 754w, https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=417&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/148632/original/image-20161205-19362-15yjala.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=417&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Would you pay more if this included DHA?</span>
<span class="attribution"><span class="source">Trail mix via www.shutterstock.com</span></span>
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<h2>What is healthy?</h2>
<p>The impact of belief in the healthy = expensive intuition, however, goes beyond just general inferences about price and health. </p>
<p>In another study, we found that consumers used this intuition when valuing the importance of an unfamiliar specific ingredient in a food product. We asked participants to assess the importance of the inclusion of DHA (docosahexaenoic acid) – which we told them helps reverse <a href="http://umm.edu/health/medical/altmed/condition/macular-degeneration">macular degeneration</a>, an age-associated eye disease that can lead to vision loss – in a trail mix. When the DHA trail mix was sold at a premium price, participants put a higher value on both <a href="http://www.blindness.org/blog/index.php/can-dha-save-your-vision/">DHA</a> and the underlying health condition. When it was sold at an average price, participants weren’t as persuaded that their diet should include DHA or that preventing macular degeneration was as important.</p>
<p>Interestingly, it was the unfamiliarity of DHA that drove these inferences. When vitamin A was associated with the same health claim, a relative price premium didn’t alter perceptions of how important vitamin A is as an ingredient. This study suggests that people are more likely to rely on their lay theories when assessing health claims that are unfamiliar – a situation they likely face often at the grocery store as food manufacturers frequently introduce new products <a href="http://www.health.com/health/gallery/0,,20599288,00.html">claiming to include the latest health ingredient</a>.</p>
<h2>Ignore your gut</h2>
<p>Together, our studies reveal that consumers have a pervasive tendency to associate healthier food products and higher prices. </p>
<p>If one is operating with an unlimited budget while trying to cook and serve healthy meals, then perhaps this isn’t a problem. However, those trying to manage a food budget and feel good about the healthiness of their family meals may pay too much for their nutrition. This can occur despite ready availability of both pricing and <a href="http://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm248732.htm">nutritional information</a>.</p>
<p>What is the takeaway for consumers? We all know that price and quality aren’t perfectly correlated, but it doesn’t stop us from <a href="http://journals.ama.org/doi/abs/10.1509/jmr.12.0407">using price to judge quality</a> when we don’t have other information.</p>
<p>So if you’re truly concerned about choosing healthy foods without overpaying, stop and think next time you see a health claim paired with a high price rather than relying on your gut feelings. A simple solution to overcoming the influence of the intuition is to seek out more information before you buy. </p>
<p>Getting more information, which mobile devices let consumers do easily, even while shopping in a store, will enable you to rely on more careful, systematic thinking about the health claim being presented – rather than just your gut’s take that a healthy idea requires emptying your wallet.</p><img src="https://counter.theconversation.com/content/69321/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 organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Consumers tend to think that healthy foods have to cost more than their less nutritional counterparts. New psychological research looks at how pervasive this is.Kelly L. Haws, Associate Professor of Marketing, Vanderbilt UniversityKevin L. Sample, Ph.D. Candidate in Marketing, University of GeorgiaRebecca Walker Reczek, Associate Professor of Marketing, The Ohio State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/261142014-06-23T04:34:38Z2014-06-23T04:34:38ZHealth Check: fish oil, anyone?<figure><img src="https://images.theconversation.com/files/51757/original/ytzgkt57-1403247120.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's been suggested that fish oil is the snake oil of our generation.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/telemetry9/3254183574">exoimperator/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>An estimated one in four Australians currently take fish oil supplements daily because of its perceived benefits. </p>
<p>There are suggestions that fish oil is good for a range of health conditions including arthritis, Alzheimer’s disease, diabetes, mental health and heart disease. It’s even been suggested that fish oil might make people smarter, so should we all be taking supplements?</p>
<h2>Good for everyone?</h2>
<p>Fish oil typically contains DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). In Western nations, low dietary intake of DHA and EPA is a concern as they are not widely available in contemporary foods. </p>
<p>DHA and EPA are derived from “essential” fatty acids in the diet (so named because humans and other mammals cannot make these substances themselves). They’re found almost exclusively in oily cold-water fish, fish oil supplements, breast milk, and supplemented infant formula. </p>
<p>The majority of research on these fatty acids have been done on DHA. And here’s what we know.</p>
<p>There’s no doubt that DHA found in fish oil is involved in several critical brain functions. Both <a href="http://www.ncbi.nlm.nih.gov/pubmed/22841917">laboratory research</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/14597908">human epidemiological studies</a> have demonstrated that a shortage of DHA can adversely affect cognition, and intake of <a href="http://www.ncbi.nlm.nih.gov/pubmed/17307104">oily fish during pregnancy</a> can benefit children’s cognitive functioning. </p>
<h2>Especially for kids?</h2>
<p>DHA is known to play a <a href="http://www.ncbi.nlm.nih.gov/pubmed/22005286">critical role in the developing human brain</a> and there’s evidence of its <a href="http://www.ncbi.nlm.nih.gov/pubmed/18789910">importance for brain development in infancy</a>. What’s more, several studies have <a href="http://www.ncbi.nlm.nih.gov/pubmed/21295417">demonstrated positive associations</a> between infant blood concentrations of DHA and cognition. </p>
<p>Indeed, long-chain polyunsaturated fatty acids including DHA have been suggested as being among the principal factors that can <a href="http://www.ncbi.nlm.nih.gov/pubmed/10695931/">increase the intelligence of breastfed individuals</a>.</p>
<p>But what about DHA supplementation in babies and children delivered via fish oil?</p>
<p>The notion that dietary DHA supplementation enhances cognition in young children remains controversial. Some have even suggested that it’s the <a href="http://www.abc.net.au/radionational/programs/healthreport/fish-oil/4694452">snake oil of our generation</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/51758/original/p7hnzbs8-1403247596.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Babies in randomised controlled trials have generally been given fish oil in formula milk.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/20661491@N04/2929200876">tofedupin/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
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</figure>
<p>Randomised controlled trials remain the gold standard in this area of research. And the trials undertaken in this field have <a href="http://www.ncbi.nlm.nih.gov/pubmed/19505812/">generally administered DHA</a> via formula milk rather than via fish oil capsules.</p>
<h2>What the science says</h2>
<p>The findings provide conflicting evidence. </p>
<p>One major review of the literature failed to identify a significant effect of DHA supplementation <a href="http://www.ncbi.nlm.nih.gov/pubmed/18253973">on cognitive development in full-term infants</a>. But <a href="http://www.ncbi.nlm.nih.gov/pubmed/19505812">another suggested</a> supplementation with a similar level of DHA to breast milk results in higher cognitive performance in young children born at full term. </p>
<p>Still, the majority of trials in healthy term infants <a href="http://www.ncbi.nlm.nih.gov/pubmed/23065239">have shown little</a> or <a href="http://www.ncbi.nlm.nih.gov/pubmed/23445847">no consistent, beneficial effects</a> on neurocognitive outcomes as a result of dietary DHA supplementation. Importantly though, infant DHA supplementation has resulted in no negative effects on growth, development or health. </p>
<p>So it appears there’s no compelling argument either for or against DHA supplementation in full-term infants for the purpose of cognitive enhancement.</p>
<h2>Possible explanations</h2>
<p>Inconsistent findings within this literature may be due to inadequate sample sizes, variations in the doses of DHA used, the source of DHA administered (algal or fish sources, for instances), the age at which supplementation was initiated, the duration of supplementation, the type of cognitive or developmental assessments undertaken, the variability in participant compliance across studies, or a combination of these factors. </p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/21106917/">Genetic profile</a> could also represent a potentially relevant factor affecting study outcomes. And <a href="http://www.ncbi.nlm.nih.gov/pubmed/23065239">gender-based differences</a> in how long-chain polyunsaturated fatty acids are metabolised have been cited as being potentially relevant. </p>
<p>Another consideration concerns potential ceiling effects: if someone is already functioning at maximal or close to maximal efficiency, then supplementing the diet with DHA is unlikely to yield significant benefits. </p>
<p>But in preterm infants – in whom there’s a possible deficit in DHA status – the effects of DHA supplementation may be more positive.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/22161363">Despite the absence of scientific consensus</a> regarding any benefits in full-term infants, many manufacturers of infant formula milk include DHA in certain products and market them as superior products offering distinct cognitive advantages. This is controversial, given the lack of concrete scientific evidence to support their claims. </p><img src="https://counter.theconversation.com/content/26114/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jonathan Foster has received funding to undertake research from the Australian Research Council and National Health and Medical Research Council and from similar government and not-for-profit funding agencies in the United Kingdom, Canada and the United States. He has received previous private sector funding from Unilever and Pfizer.</span></em></p>An estimated one in four Australians currently take fish oil supplements daily because of its perceived benefits. There are suggestions that fish oil is good for a range of health conditions including…Jonathan Foster, Curtin Senior Fellow, Professor & Clinical Neuropsychologist, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.