tag:theconversation.com,2011:/us/topics/cows-milk-44544/articlescow's milk – The Conversation2021-02-23T15:05:04Ztag:theconversation.com,2011:article/1552532021-02-23T15:05:04Z2021-02-23T15:05:04ZBreast cancer: is milk a risk factor?<figure><img src="https://images.theconversation.com/files/385838/original/file-20210223-22-56pbn6.jpg?ixlib=rb-1.1.0&rect=17%2C8%2C5734%2C3819&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some studies have linked drinking milk with higher risk of oestrogen-receptor positive breast cancer.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-drinking-milk-362409509">Summersky/ Shutterstock</a></span></figcaption></figure><p>Breast cancer has now overtaken lung cancer as the world’s <a href="https://www.who.int/news/item/03-02-2021-breast-cancer-now-most-common-form-of-cancer-who-taking-action">most commonly diagnosed</a> cancer, and as the <a href="https://pubmed.ncbi.nlm.nih.gov/30207593/">leading cause</a> of cancer-related deaths for women in many countries. While genetics can certainly increase risk of the disease, for most women <a href="https://www.cancerresearchuk.org/about-cancer/breast-cancer/risks-causes/risk-factors">lifestyle factors</a>, such as alcohol or being overweight or obese, are bigger influences on developing breast cancer. Now, two separate studies, both published in 2020, have identified cow’s milk as another possible risk factor for breast cancer.</p>
<p>The <a href="https://pubmed.ncbi.nlm.nih.gov/33004231/">first study</a>, which looked at 33,780 Swedish women since 1997, found that about 300 millilitres of cow’s milk per day (the equivalent of a large mug) increased breast cancer risk by about a third compared to women who did not drink milk. </p>
<p>The <a href="https://academic.oup.com/ije/article-abstract/49/5/1526/5743492?redirectedFrom=fulltext">second study</a>, from the US, looked at 52,795 over a period of nearly eight years and found that women who drank about 300 millilitres of milk per day had a 50% increased risk for breast cancer compared with those who drank very little milk.</p>
<p>Both studies found that the risk was mostly limited to post-menopausal women who developed a type of breast cancer stimulated by oestrogen, called <a href="https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-hormone-receptor-status.html">oestrogen-receptor positive</a> breast cancer. There was no increased risk of other types of breast cancer which rely on other growth factors (such as <a href="https://www.breastcancer.org/symptoms/diagnosis/her2">HER2 positive</a> breast cancer). </p>
<p>But because of their design, the studies could only conclude that there was an association between milk consumption and breast cancer – they could not prove that drinking milk caused cancer. The authors of the studies took into account other known causes of breast cancer that might have explained their results, such as the woman’s age when she had her first period and menopause, and alcohol consumption. But the authors could still not completely discount all other possible explanations for their findings. So how important is milk as a cause of this type of breast cancer?</p>
<p>To understand why cow’s milk might increase risk of oestrogen-receptor positive breast cancer, it’s important to look at biological studies, which can help us see which mechanisms are taking place in the body. Cow’s milk naturally contains stimulants for cell growth and division. These stimulants act in the body by raising levels of a growth factor called IGF1 (insulin-like growth factor 1). Studies show that in humans, it’s these raised levels of IGF1 that are <a href="https://pubmed.ncbi.nlm.nih.gov/25743390/">strongly implicated</a> in increasing breast cancer risk, which may be why drinking milk is linked <a href="https://pubmed.ncbi.nlm.nih.gov/16900085/">to greater risk</a>. </p>
<p>Interestingly, fermented dairy products (yogurt and cheese) did not increase breast cancer risk in either of the earlier studies. This may be because yogurt and cheese <a href="https://pubmed.ncbi.nlm.nih.gov/31089868/">do not increase</a> IGF1 levels in the body. This could be because the IGF1-stimulating factors present in milk are lost during the making of cheese and yogurt.</p>
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<img alt="Bowl of plain yoghurt with wooden spoon." src="https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385839/original/file-20210223-24-chayb.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">Fermented dairy products don’t increase IGF1 levels.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/homemade-yogurt-sour-cream-wooden-bowl-515797933">DONOT6_STUDIO/ Shutterstock</a></span>
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<p>IGF1 does not increase breast cancer risk on its own. Rather, its ability to stimulate cell growth is <a href="https://pubmed.ncbi.nlm.nih.gov/33364239/">greatly magnified</a> by oestrogen. This could explain why in the two studies, high milk consumption increased the risk for oestrogen-receptor positive breast cancer, but not for other types. It may be that both oestrogen and IGF1 are needed for breast cells to become cancerous – and that this can only happen in cells that respond to oestrogen as well as to IGF1.</p>
<h2>Other risk factors</h2>
<p>As well as milk, many other factors that increase the risk for breast cancer also act by raising levels of IGF1 or oestrogen in the body. Obesity raises levels of both <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2639294/">IGF1 and oestrogen</a> in post-menopausal women. And an early menarche, a late menopause and drinking alcohol <a href="https://www.wcrf.org/breast-cancer-2017">all increase</a> the duration and amount of breast cells’ exposure to oestrogen.</p>
<p>Since many risk factors influence oestrogen and IGF1 levels, it’s too simplistic to point the finger of blame for breast cancer at only one food, such as milk. Many factors need to be considered. This may help explain why, for example, Belgium, the Netherlands, and Luxembourg occupy the <a href="https://www.wcrf.org/dietandcancer/cancer-trends/breast-cancer-statistics">top three spots</a> in the world for breast cancer incidence. <a href="https://worldpopulationreview.com/country-rankings/milk-consumption-by-country">Milk consumption</a> is high in the Netherlands, but it’s not particularly high in Belgium or Luxembourg. And while <a href="https://www.oecd.org/els/health-systems/Obesity-Update-2017.pdf">obesity rates</a> for women in these countries is high, they are certainly not the highest in the world. Neither is their <a href="https://ec.europa.eu/jrc/en/page/alcohol-daily">alcohol consumption</a> especially high. So it’s probably the coming together of many risk factors elevating oestrogen and IGF1 levels that contributes to the especially high incidence of breast cancer in the Benelux countries.</p>
<p>It’s equally important to consider protective factors. Physical activity lowers the risk of breast cancer and improves survival in breast cancer patients, and this is linked to <a href="https://pubmed.ncbi.nlm.nih.gov/27562357/">lowering IGF1 levels</a>. Diet can also protect against raised levels of oestrogen and IGF1. Some foods contain substances called phytoestrogens that block the action of oestrogen. For instance, extra virgin olive oil is an <a href="https://pubmed.ncbi.nlm.nih.gov/23332727/">exceptionally rich</a> source. This may also partly explain why women who eat a Mediterranean diet (which traditionally doesn’t include cow’s milk) are at a <a href="https://pubmed.ncbi.nlm.nih.gov/26365989/">lower risk of breast cancer</a>. So while cow’s milk may be a risk factor for breast cancer, it acts alongside many other risk factors.</p><img src="https://counter.theconversation.com/content/155253/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Hoffman has previously received funding from NIHR. He is the author of two books on the Mediterranean diet: The Mediterranean Diet: Health and Science (2011) and More Healthy Years - Why a Mediterranean Diet is best for you and for the planet (2020).</span></em></p>Cow’s milk naturally raises levels of a growth factor strongly implicated in breast cancer risk.Richard Hoffman, Associate lecturer, Nutritional Biochemistry, University of HertfordshireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1082552018-12-06T09:55:20Z2018-12-06T09:55:20ZInfant formula companies are behind the guidelines on milk allergy, and their sales are soaring<figure><img src="https://images.theconversation.com/files/249170/original/file-20181206-186052-1inle1h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Infant formula manufacturers have been funding the development of guidelines for the diagnosis and treatment of cows' milk allergy in infants.</span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p>There has been a six-fold increase in sales of infant formula prescribed for babies with cows’ milk protein allergy in the United Kingdom from 2006 to 2016. This is despite no evidence of a concurrent increase in the prevalence of infants with the allergy. </p>
<p>An investigation published today in the <a href="https://www.bmj.com/content/363/bmj.k5056">BMJ</a> found infant formula manufacturers have been funding the development of guidelines for the diagnosis and treatment of cows’ milk allergy as well as providing research and consultancy funds to those who wrote them.</p>
<p>Rates of cow’s milk allergy appear to have been <a href="https://www.ncbi.nlm.nih.gov/pubmed/25864712">relatively stable</a> – estimated at between 1-2% over the last decade. </p>
<p>Research has found the perception of an allergic response to cow’s milk protein in children is <a href="https://www-ncbi-nlm-nih-gov.ezproxy.uws.edu.au/pmc/articles/PMC3716921/">ten times greater</a> than what actual diagnosis would indicate. This means guidelines on allergy for doctors are really important.</p>
<p>In some cases, doctors who spoke to the BMJ said the guidelines were so vague that</p>
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<p>virtually every single infant could potentially be diagnosed using these symptoms. </p>
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<p>A diagnosis can only be made only by excluding cow’s milk protein from the maternal diet, observing symptoms, and then reintroducing it. But the BMJ paper notes that <a href="https://www.ncbi.nlm.nih.gov/pubmed/30306546?dopt=Abstract">evidence for advising</a> such exclusions to treat non-specific symptoms in breastfed infants is weak.</p>
<p>The paper also found much of the education for health professionals and parents about cows’ milk allergy was provided by organisations also funded by the infant formula industry.</p>
<p>Previous <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001500">research has found</a> that changes in diagnostic and treatment guidelines can have enormous effects on the revenue of pharmaceutical and nutritional products. Conflicts of interest due to industry funding have been <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1000352">found to affect</a> doctors’ prescribing behaviour, research results and the quality of patient care.</p>
<p>Parents are also vulnerable to marketing. They crave a happy, quiet, calm baby who sleeps, eats and poos in a predictable pattern. </p>
<p>But babies wake often. They can have difficulty adjusting to life outside the womb and their stomachs are getting used to digesting food. They vomit. They cry for reasons that are hard to understand. </p>
<p>Marketing takes this normal infant behaviour and turns it into a problem that can be solved by buying a product.</p>
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Read more:
<a href="https://theconversation.com/why-advertisers-use-pictures-to-sell-pharmaceuticals-and-shouldnt-53968">Why advertisers use pictures to sell pharmaceuticals – and shouldn't</a>
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<p>When businesses are allowed to shape the guidelines health professionals use to diagnose and treat, this can lead to guidelines that find normal infant behaviour is treatable – with a product. </p>
<p>Unfortunately there may similar pressures on doctors in Australia.</p>
<p>A variety of infant formula products available in Australia claim to be antidotes to normal challenges new parents face such as crying, vomiting and constipation. </p>
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<a href="https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249161/original/file-20181206-186070-10nz4x9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&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">An advertisement in Australian Doctor.</span>
<span class="attribution"><span class="source">.</span>, <span class="license">Author provided</span></span>
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<p>The above advertisement is from the publication <a href="https://www.australiandoctor.com.au/">Australian Doctor</a> (which is available through subscription to medical professionals and includes drug advertising). It is a powerful piece of persuasion. It invokes every parent’s desire for a good night’s sleep and a contented, healthy baby to drive purchasing behaviour. Notice the presence of the mother in this picture. Although we can’t see her, we presume she is also sleeping somewhere. </p>
<p>When parents are desperate for help, doctors want to provide it. Colic is a variation of normal infant behaviour. It has no known medical cause or cure and this can make doctors feel powerless. However, this advertisement offers them a way to help. It gives doctors a solution – they just need to suggest the infant formula. </p>
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Read more:
<a href="https://theconversation.com/my-baby-is-crying-is-it-colic-how-can-i-help-62952">My baby is crying. Is it colic? How can I help?</a>
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<p>Parents are told to seek assistance from health professionals when they are concerned about their baby. However, if health professional guidelines and education is contaminated with marketing and influenced in other ways by infant formula manufacturers, the support they provide will be of poor quality. </p>
<p>Health professionals need independent, non-commercial information on infant feeding and parents should be protected from predatory marketing through effective enforcement of regulations.</p><img src="https://counter.theconversation.com/content/108255/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karleen Gribble is affiliated with the Infant and Young Child Feeding in Emergencies Core Group, the World Breastfeeding Trends Initiative, and the Australian Breastfeeding Association. </span></em></p><p class="fine-print"><em><span>Nina J Berry's research is supported by funding from Australian Government Department of Health; the Australia Indonesia Centre and the University of Sydney. Dr Berry is a member of the International Union for Health Promotion and Education; the Public Health Association of Australia; the Asian Studies Association of Australia; the World Public Health Nutrition Association; Collaboration on Social Science in Immunisation; the Sydney Global Child Health Research Network; the Sydney South East Asia Centre; the Sydney Lifespan Research Network; and volunteers as a trainer, assessor, and counsellor for the National Breastfeeding Helpline.</span></em></p>New research shows a six-fold increase in sales of infant formula prescribed for babies with cows’ milk protein allergy in the UK, despite no evidence of an increase in the incidence of the allergy.Karleen Gribble, Adjunct Associate Professor, School of Nursing and Midwifery, Western Sydney UniversityNina Jane Chad, Post-doctoral Research Associate, Sydney School of Public Health, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/846282017-10-11T12:19:03Z2017-10-11T12:19:03ZWhy asking what causes autism is the wrong question<figure><img src="https://images.theconversation.com/files/189379/original/file-20171009-6971-1bb0f8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cow's milk ... blamed for autism.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/542317249?src=sav7i-CR9XyNBq-x01q1PA-1-7&size=medium_jpg">Shutterstock</a></span></figcaption></figure><p>The <a href="https://www.peta.org/features/got-autism-learn-link-dairy-products-disease/">animal rights charity PETA</a> recently made a link between autism and drinking cow’s milk. The article on its website discussed research that linked a dairy-free diet with a reduction in <a href="https://themighty.com/2017/09/peta-got-autism-campaign/">symptoms of autism in children</a>. The charity cited two particular research projects which suggest a link between drinking cow’s milk and autism. It was originally released a few years ago, but has recently been <a href="https://www.plantbasednews.org/post/old-peta-advert-associating-milk-with-autism-has-caused-outrage">relaunched on social media</a> causing much discussion.</p>
<p>The research that underpins PETA’s claim is based on two small-scale studies. <a href="https://www.ncbi.nlm.nih.gov/pubmed/12168688">One was a “blind” study</a> of 20 children, half of whom were given a diet free from gluten and casein – a protein found in mammalian milk – and half who had an unchanged diet. The children were observed for a year and the study concluded that the development of the children in the experimental group was significantly better than the control.</p>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pubmed?uid=8869369&cmd=showdetailview&indexed=google">second study</a> similarly concluded that there may be a link between allergies, such as to cow’s milk, and autism. But both studies are based on very small numbers of children and while they suggest a potential link they do not conclude that an allergy to cow’s milk or gluten causes autism.</p>
<p>There is a long tradition of linking particular behaviours, diets, or public health measures to the development of autism. The most reported, and controversial, link was between the MMR vaccine and development of autism. In 1998, a research paper was published that suggested that the “triple” vaccine against MMR (measles, mumps and rubella) can cause autism in some children. </p>
<p>This has been discredited and widely disproved in medical science research. But the impact of this style of reporting scientific research continues.</p>
<h2>Negative spin</h2>
<p>We <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1354-4187.2005.00304.x/full">have investigated</a> how research such as this is reported and would argue that it frames autism negatively – something that is to be avoided. </p>
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<img alt="" src="https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/189381/original/file-20171009-6971-1psp2s8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The link between the MMR vaccine and autism has been discredited.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/250957000?src=yMv4pJJshh870c2uuZMUBA-1-20&size=medium_jpg">Shutterstock</a></span>
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<p>The media reporting of a link between MMR and autism, for example, received a disproportionate amount of press coverage and led to some parents using the media to talk about their autistic children as <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1354-4187.2005.00304.x/full">“vaccine damaged”</a>.</p>
<p>The impact of this media reporting and the original research article led to many parents not vaccinating their children, which directly led to outbreaks of measles as those children who missed being vaccinated in <a href="http://www.wales.nhs.uk/sitesplus/888/page/66389">the late 1990s reached teenage</a> years. The vast majority of children who contracted measles in Wales in the outbreak in 2012/13 had never been vaccinated. This is in stark contract to the <a href="http://www.wales.nhs.uk/sitesplus/888/page/66389">“near elimination”</a> of the illness in earlier years. </p>
<p>The issue we have with linking the development of autism to factors such as drinking milk or the triple vaccine is that by implication it portrays autistic children as damaged (for example, by a vaccination or unhealthy diet) or as unwanted. The assumption stemming from this kind of reporting is that parents would not want a child with autism. It also blames parents and carers for poor decisions that have led to the problem.</p>
<p>Rather than blaming parents for having an autistic child, there is a need to understand autism and to value autistic children and the families they live in. Asking what causes autism is asking the wrong question. Asking how we as a society value the skills, abilities and qualities of autistic children and adults is a much better one.</p><img src="https://counter.theconversation.com/content/84628/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lindsay O'Dell received funding from The Leverhulme Trust.
I am also a member of the Labour Party but I don't think that this is relevant</span></em></p><p class="fine-print"><em><span>Charlotte Brownlow has received funding from The Leverhulme Trust, UK </span></em></p>We need to stop playing the blame game.Lindsay O'Dell, Senior Lecturer, Children & Young People, The Open UniversityCharlotte Brownlow, Associate Professor Psychology, University of Southern QueenslandLicensed as Creative Commons – attribution, no derivatives.