tag:theconversation.com,2011:/africa/topics/colostrum-19723/articlesColostrum – The Conversation2017-06-02T02:40:30Ztag:theconversation.com,2011:article/783992017-06-02T02:40:30Z2017-06-02T02:40:30ZHealth Check: is it safe to express milk before giving birth?<figure><img src="https://images.theconversation.com/files/171590/original/file-20170531-25664-1awgx8t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some women, especially with diabetes, are recommended to express milk while still pregnant and to save it for their newborn. But it's not for everyone.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/480007972?size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>Late in their pregnancies, some women notice <a href="https://www.sciencedaily.com/terms/colostrum.htm">colostrum</a> (early milk) leaking from their nipples.</p>
<p><a href="http://brochures.mater.org.au/brochures/mater-mothers-hospital/breastfeeding%E2%80%94antenatal-expression-of-colostrum">Some hospitals</a> are advising women to collect this milk in the last weeks of pregnancy, ready to give to their newborn baby, if needed. Midwives, doctors and lactation consultants may suggest this in particular to women with diabetes in pregnancy.</p>
<p>Although collecting colostrum before giving birth is not new, it is now <a href="http://thehealthyhoneys.com/why-i-chose-to-express-my-colostrum-before-giving-birth/">more widely promoted</a>. Yet there has been little research on the practice. And some people are concerned that collecting it when pregnant could bring on labour early, potentially <a href="https://www.breastfeeding.asn.au/bfinfo/antenatal-expression-colostrum">increasing the risk</a> to mother and baby.</p>
<p>So is it safe for women to collect their own colostrum while pregnant? And are there some situations that are more risky than others?</p>
<h2>What is colostrum and how do women collect it?</h2>
<p>Colostrum contains high levels of antibodies, the proteins that not only fight infections but <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257684/">program a baby’s immune system for life</a>. We don’t know why some women’s breasts start producing colostrum in pregnancy; many women won’t have any until after they give birth.</p>
<p>If women are advised to collect colostrum while still pregnant, they usually “express” these early drops of fluid <a href="http://brochures.mater.org.au/home/brochures/mater-mothers-hospital/breastfeeding-antenatal-expression-of-colostrum">by stimulating their nipples by hand</a> rather than using a breast pump. </p>
<p>The amount women collect varies from nothing, to a few drops, to a teaspoonful or more. They collect it in a syringe or small sterile jar, which they <a href="https://abm.me.uk/expressing-milk-baby-arrives-antenatal-expression-colostrum/">store in the freezer</a> at home. They then bring it (still frozen) to the hospital when they give birth, where it is thawed if needed to give to the newborn baby while he or she is one or two days old.</p>
<h2>Why do women collect it?</h2>
<p>The most common reason why women consider expressing colostrum early is if they have diabetes in pregnancy, whether that’s existing diabetes or diabetes that only came on while pregnant (pregnancy-onset or gestational diabetes).</p>
<p>Before birth, all babies receive a continuous supply of food in the form of glucose from their mother. This stops suddenly at birth and as babies transition to life outside the womb they have a period of low blood sugar (hypoglycaemia).</p>
<p>However, this adaptation to outside life <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1786710/">takes longer</a> for babies of mothers with diabetes. About one in four or five of these babies <a href="https://www.ncbi.nlm.nih.gov/pubmed/24292970">develop hypoglycaemia</a> soon after birth. If untreated, this could <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4659381/">cause seizures or brain damage</a>.</p>
<p>To treat hypoglycaemia these babies are often supplemented with infant formula since mothers’ milk does not “come in” for a <a href="https://www.ncbi.nlm.nih.gov/pubmed/26113051">couple of days after birth</a>.</p>
<p>While breast milk is <a href="https://www.ncbi.nlm.nih.gov/pubmed/19226355">much better</a> than formula at bringing blood sugar to normal levels, there may not be enough milk in the breast to boost the newborn baby’s blood sugar levels. So babies of women with diabetes are more likely to be admitted to a <a href="https://www.ncbi.nlm.nih.gov/pubmed/15790322">special care nursery</a> for treatment. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/171579/original/file-20170531-25697-1fzw1b8.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 most common reason for women considering expressing milk while pregnant is if they have diabetes.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/272961047?src=97kC_V7OjcDyj6J-Is7YGQ-1-15&size=medium_jpg">from www.shutterstock.com</a></span>
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<p>But if the mother has a small supply of breast milk ready to feed the baby – a few millilitres in a syringe or spoon – they could avoid this.</p>
<p>If the mother has collected colostrum before birth, the newborn baby may also be less likely to need infant formula, which has a number of <a href="https://www.ncbi.nlm.nih.gov/pubmed/8583288?dopt=Abstract&holding=npg">risks to the immature gut</a>. Giving formula based on cow’s milk to newborns may also increase their <a href="https://www.ncbi.nlm.nih.gov/pubmed/26192405">risk of allergies</a> and <a href="https://academic.oup.com/nutritionreviews/article/70/9/509/1835283/Current-evidence-on-the-associations-of">developing diabetes</a> themselves.</p>
<p>Other women may want to <a href="https://www.breastfeeding.asn.au/bfinfo/antenatal-expression-colostrum">express milk before giving birth</a> because they had a low milk supply with a previous baby or they know their baby has a medical condition that might make it hard to breastfeed well, like a heart condition.</p>
<p>While there can be short-term benefits to newborn babies from being fed colostrum expressed before birth, no one has studied if there are any longer-term benefits.</p>
<p>There also doesn’t seem to be <a href="http://joe.endocrinology-journals.org/content/74/3/509.extract">much difference</a> between the quality of the colostrum expressed before birth and colostrum expressed 24 hours afterwards.</p>
<h2>Risks to mother and baby</h2>
<p>By stimulating their nipples and expressing milk while pregnancy, women could bring on <a href="https://www.ncbi.nlm.nih.gov/pubmed/26444882">regular contractions</a> of the womb and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538605/">give birth early</a>. </p>
<p>This is because nipple stimulation leads to an <a href="https://www.ncbi.nlm.nih.gov/pubmed/2618602">increase in the hormone oxytocin</a>, which plays a role in both milk <a href="https://www.breastfeeding.asn.au/bf-info/early-days/let-down-reflex">let-down</a> and contraction of the womb.</p>
<p>For this reason, women who need a caesarean (for instance if their baby is not “head down” or if they have had previous caesareans), have been advised <a href="http://bmjopen.bmj.com/content/4/10/e006571.long">not to express while pregnant</a>.</p>
<p>Another concern is that stimulating the nipple and the increased contractions could reduce blood flow to the womb. So, expressing while pregnant <a href="http://bmjopen.bmj.com/content/4/10/e006571.long">is not recommended</a> when the foetus is not growing well, or has other medical conditions such as macrosomia (excessive weight), or there is too much fluid in the womb.</p>
<h2>Is it right for me?</h2>
<p>Our <a href="http://www.latrobe.edu.au/jlc/research/breastfeeding/dame">study</a> results, published <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)31373-9/abstract">today</a> in The Lancet, found that expressing while pregnant is safe for women with diabetes in low-risk pregnancies in late pregnancy (from around 36 weeks). After studying over 600 women, we found no increase in early births or admissions to neonatal intensive care. However, one in four women couldn’t collect any colostrum.</p>
<p>Before our trial, researchers had only run <a href="http://www.sciencedirect.com/science/article/pii/S0266613812000174">three small studies</a> of expressing colostrum while pregnant, and no randomised trials for women without diabetes.</p>
<p>So, our advice to women with questions about expressing while pregnant is to ask their health care professional about their individual situation. They are best placed to discuss the risks and benefits.</p><img src="https://counter.theconversation.com/content/78399/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lisa Amir receives funding from National Health and Medical Research Council. She is the Editor-in-Chief of the International Breastfeeding Journal.</span></em></p><p class="fine-print"><em><span>Della Forster receives funding from National Health and Medical Research Council</span></em></p><p class="fine-print"><em><span>Susan Walker is also affiliated with Mercy Perinatal.</span></em></p><p class="fine-print"><em><span>Anita Moorhead 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>Hospitals sometimes recommend women express milk towards the end of their pregnancies. But it’s not suitable for all.Lisa Amir, Associate Professor in Breastfeeding Research, La Trobe UniversityAnita Moorhead, Trial Co-ordinator, La Trobe UniversityDella Forster, Professor of Midwifery and Maternity Services Research, La Trobe UniversitySusan Walker, Professor of Obstetrics and Gynaecology, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/683952016-11-10T08:19:22Z2016-11-10T08:19:22ZCaptive panda cubs are drinking the wrong milk – here’s why<figure><img src="https://images.theconversation.com/files/145246/original/image-20161109-19051-4qpii6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">'No more milkshake for me.'</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-249906574/stock-photo-panda-triplets-half-birthday-the-triplets-which-reached-6-month-old-on-feb-1-were-the-fourth-set-of-giant-panda-triplets-born-with-the-help-of-artificial-insemination-procedures-in-chi.html?src=cp80o4WH7mhLDuFmY_7vTw-1-95">Plavevsky</a></span></figcaption></figure><p>Forty years after giant panda numbers <a href="http://wwf.panda.org/what_we_do/endangered_species/giant_panda/panda/how_many_are_left_in_the_wild_population/">reached</a> an all-time low, specialists around the world are still trying to develop a self-sustaining population in captivity that can be released into the wild to secure the animal’s future. </p>
<p>This has been <a href="http://www.cbsg.org/sites/cbsg.org/files/Traylor-Holzer_Ballou_2016.pdf">hampered</a> over the years by institutions failing to work together and follow the breeding recommendations of genetic scientists. In China in particular, the home of giant pandas, breeders have prioritised cub numbers over quality. The problem is that the competing ministries responsible for panda populations are paid for each cub they produce. </p>
<p>There have long <a href="http://www.cambridge.org/catalogue/catalogue.asp?isbn=9780521832953">been concerns</a> that breeding pandas in the wrong way produces cubs in captivity with health and behavioural problems. These problems exacerbate the difficulties of giant panda reproduction and make them less capable of coping in the wild. </p>
<p>We have <a href="http://www.nature.com/articles/srep36141">just published</a> new research into panda milk that adds to the growing evidence of how human interference can be bad for these animals. It relates to the fact that in China it is standard practice in breeding centres to intensively supplement – or even entirely replace – the mother’s milk with an artificial substitute. In Chinese husbandry culture, the belief is that this is the best way of ensuring the cubs have the best chance of survival and grow as quickly as possible. </p>
<p>Practices vary in other countries, often depending on the nature of the panda loan agreement they have with the Chinese authorities. In many cases, they are required to have a Chinese zookeeper overseeing the pandas at all times, in which case they will follow Chinese practice. (One example of a zoo that doesn’t interfere with panda milk is <a href="https://www.zoovienna.at/en/zoo-and-visitors/visitor-information/">Vienna</a>). </p>
<h2>The colostrum conundrum</h2>
<p>Milk is particularly important for giant pandas because of the extreme immaturity of a newborn panda cub. All bears are born more developmentally immature than any other mammal apart from marsupials, and of the seven bear species, giant pandas are born most immature of all. </p>
<p>Newborn pandas weigh only 100-150g, about 1/1,000th the weight of their mothers. They have no functioning immune system, cannot see or hear, and cannot regulate their own body temperature. They are naked and completely dependent on the mother for every aspect of survival and development. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145247/original/image-20161109-19097-1ktv5ey.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Panda junior.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-211947010/stock-photo-guangzhou-china-august-12-2014a-newborn-giant-panda-cub-one-of-the-triplets-which-were-born-to-giant-panda-juxiao-not-pictured-is-seen-inside-an-incubator-at-the-chimelong-safari.html?src=cp80o4WH7mhLDuFmY_7vTw-1-92">Plavevsky</a></span>
</figcaption>
</figure>
<p>As readers with children will be well aware, mothers produce a special milk in the first few days after giving birth which is unique in its composition of specific nutrients. Known as colostrum, this first milk contains specific types and concentrations of substances essential for the newborn’s immune system, as well as proteins, lipids and other molecules that are vital for development. </p>
<p><a href="http://jmammal.oxfordjournals.org/content/90/2/332">In species</a> that are born fairly mature, such as calves and foals, the colostrum phase of milk lasts only a few hours. In our <a href="http://www.nature.com/articles/srep36141">new paper</a>, which is the third in a <a href="http://rsos.royalsocietypublishing.org/content/2/10/150395">series</a> of <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0143417">papers</a> about giant panda milks, we hypothesised that the transition from colostrum to mature milk would be unusually long in bears in order to meet the requirements of a developmentally immature newborn. Sure enough, when we analysed milk samples from six giant pandas, the colostrum phase turned out to last 30 to 40 days. </p>
<p>We also found that the composition of the milk varied greatly over the period, with some ingredients starting off in large proportions and falling away while others started low and rose dramatically. Some of the most noticeable changes related to small molecules that are building blocks for the eye, brain and nervous system. </p>
<p>Other fluctuating ingredients are integral to cubs’ biosynthetic pathways, cell membranes, antibacterial defences and establishing microorganisms in their digestive system. These microorganisms <a href="https://www.ncbi.nlm.nih.gov/pubmed/26143242">may be</a> particularly important to giant pandas as they progress from a milk-based to a predominately vegetarian diet within the first year of life: giant pandas may depend on a unique gut microbiome to be able to digest the large quantities of bamboo that form the foundation of their diet.</p>
<p>We also analysed the artificial milk formulae that breeders commonly use to supplement giant panda cubs. We found that key compounds were at extremely inappropriate levels – some too low, others too high. They also stayed at these levels, not changing like the mother’s colostrum to meet the needs of the developing infant. </p>
<p>For example, we discovered that the artificial milk had a gross excess of lactose, which is abundant in cow and other milks but disappears from panda colostrum after the first day or two. This lactose <a href="http://samples.sainsburysebooks.co.uk/9780470384787_sample_382126.pdf">causes</a> panda cubs severe stomach problems and disrupts the fragile balance of microorganisms in their gut, which can hamper their digestive processes for the rest of their lives. </p>
<p>At the same time, we found major deficiencies in other key compounds in the artificial milk that may be compromising the development of the cubs’ brains, eyes and other organs – a grave risk considering the ultimate intention is to release captive-bred individuals into the wild. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145248/original/image-20161109-19074-beqfh9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">‘Who you calling idle?’</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-137297054/stock-photo-panda-bear.html?src=cp80o4WH7mhLDuFmY_7vTw-1-18">Lee Yiu Tung</a></span>
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<h2>The wider problem</h2>
<p>In the wild, panda mothers invest extraordinary time and skill rearing their infants to be sufficiently adaptive and resilient to survive. We still have a great deal to understand about this process, and our research reveals what is probably one of a number of ways in which panda cubs suffer when breeders prevent panda mothers from raising their cubs undisturbed. </p>
<p>It is probably equally unhelpful, for example, that panda families are interfered with hourly and live in barren enclosures where mothers have no privacy or control over their environment. At three to five months of age, cubs bred in captivity are permanently removed from their mothers to maximise the chances of the mothers reproducing every year. This is very different from the wild, <a href="https://www.abebooks.co.uk/Last-Panda-Schaller-George-B-University/16569203262/bd">where</a> cubs stay with their mothers for at least two and a half years and females reproduce only every four to five years. </p>
<p>If we wish to build a captive panda population of bear cubs that are physically, cognitively and behaviourally healthy, breeders need to leave mothers to their work. Our research emphasises the evolutionary wisdom that no one else is better suited to that job.</p><img src="https://counter.theconversation.com/content/68395/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Kennedy has received funding over the years from The Wellcome Trust, the Medical Research Council (UK), The Royal Society, The Carnegie Trust for the Universities of Scotland, the International Science and Technology Cooperation Program of China, and the Biotechnology and Biological Sciences Research (UK). The project in this paper was funded only by the universities of Glasgow and Strathclyde. </span></em></p><p class="fine-print"><em><span>Kati Loeffler 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>New research shows why the milk of panda mothers is far better than formula.Malcolm Kennedy, Professor of Natural History, University of GlasgowKati Loeffler, Adjunct Professor of Veterinary Medicine, North Carolina State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/579132016-04-21T14:25:50Z2016-04-21T14:25:50ZBreast milk is a marvel of nature but that doesn’t mean adults should drink it to see off disease<figure><img src="https://images.theconversation.com/files/119440/original/image-20160420-25601-1cxpj2y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Don't give it to grandad.</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=breast%20milk&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=271722359">www.shutterstock.com</a></span></figcaption></figure><p>A woman’s claim that she <a href="http://www.dailymail.co.uk/news/article-3542866/Helen-swears-breast-milk-gave-dying-dad-extra-year-life-right.html">extended her father’s life</a> by more than a year by feeding him expressed milk has led many to ask whether human milk can really delay the growth of cancer. The gold standard nutrition for infants, human milk is not, however, a replacement for conventional medicine in the treatment of adult diseases.</p>
<p>Human milk is perfectly composed for babies, including both nutrient and bioactive components that promote growth and development. <a href="http://www.nhs.uk/Conditions/pregnancy-and-baby/Pages/benefits-breastfeeding.aspx">Official guidance</a> in the UK recommends exclusive human milk feeding for the first six months of life. Continued breastfeeding for one to two years or longer is then endorsed by various organisations, <a href="http://www.who.int/topics/breastfeeding/en/">including the WHO</a>.</p>
<h2>Changeable milk</h2>
<p>The composition of human milk varies. <a href="http://www.cell.com/trends/biochemical-sciences/fulltext/S0968-0004%2816%2900045-1">Research</a> shows that it changes within feeds, across the day, across lactation, and between different women. This variability benefits the infant as they grow and develop. </p>
<p>The first fluid produced after delivery is colostrum. It is produced in low quantities and is rich in compounds that boost the immune system (such as leukocytes, secretory immunoglobulin A, and lactoferrin), as well as others that support growth and development (like epidermal growth factor). However, colostrum is relatively low in lactose, potassium, and calcium, leading <a href="http://ssu.ac.ir/cms/fileadmin/user_upload/Mtahghighat/tfood/ARTICLES/milk/Human_Milk_Composition.pdf">researchers</a> to conclude its function is not primarily to provide nutrition. </p>
<p>Within days the composition changes, lactose increases, marking the production of what many call “<a href="http://ajcn.nutrition.org/content/53/5/1197.short">transitional milk</a>”. This change in the milk can be delayed if the baby is delivered preterm or if the mother has a metabolic condition or is obese.</p>
<p>Across the next few weeks, milk production increases rapidly. This is to support the changing nutritional and developmental needs of the growing infant. Within a month to six weeks, the milk becomes fully mature. </p>
<h2>Complex stuff</h2>
<p><a href="http://ssu.ac.ir/cms/fileadmin/user_upload/Mtahghighat/tfood/ARTICLES/milk/Human_Milk_Composition.pdf">Mature milk</a> provides around 65 to 70 calories per 100g, which come from about 4g of fat, 7g of carbohydrate, and 1g of protein. But this composition is constantly changing. The variation in calories is primarily due to differences in fat content. Fat content is significantly lower at night and morning compared with afternoon or evening milk. It also varies within the feed itself. Milk at the end of the feed has <a href="https://www.researchgate.net/profile/Chantal_Lau/publication/12944835_Feeding_strategies_for_premature_infants_Beneficial_outcomes_of_feeding_fortified_human_milk_versus_preterm_formula/links/0deec536d7c743b2d0000000.pdf">higher levels</a> than the initial flow.</p>
<p>The composition of milk also varies with maternal diet, especially the amount and type of fatty acid. Many women in developed countries aren’t getting enough fatty acid – important for infant brain development – in their diet and this affects the composition of their breast milk. For example, low levels of docosahexaenoic acid (DHA) – an omega 3 fatty acid – consumed by North American mothers translates to low levels in their milk. This has led some <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566653/">researchers</a> to suggest that mothers should take appropriate supplements. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some mothers might benefit from taking fatty acid supplements.</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=&search_tracking_id=TU9ndqjQrevZ5pNRYs_6nA&searchterm=fish%20oil%20supplement&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=288277154">www.shutterstock.com</a></span>
</figcaption>
</figure>
<h2>More than just nutrition</h2>
<p>But human milk doesn’t just contain nutrition; it contains a variety of compounds with medicinal qualities that are important for the baby’s survival. These “growth factors” are numerous and have wide-ranging effects. For instance, epidermal growth factor is important for the development and repair of the gastrointestinal tract. Insulin-like growth factors are critical in stimulating growth and development, with high levels of some <a href="https://www.researchgate.net/publication/16992978_Immunoreactive_Somatomedin-CInsulin-Like_Growth_Factor_I_and_Its_Binding_Protein_in_Human_Milk">linked</a> to neural, and cochlea development in the ear. There are many growth factors, and they affect many important functions, including the development of the blood vessels, metabolism, intestinal system, nervous system, and endocrine (hormone) system. </p>
<p>Human milk also has important immune impacts, protecting against inflammation and infection. Oligosaccharides (a carbohydrate) encourage the growth of organisms that plays an essential role in early bacterial colonisation of the intestine which have important impacts on gut health and general well-being in later life, while also reducing vulnerability to some pathogens, such as <a href="http://jid.oxfordjournals.org/content/190/10/1850.full">noroviruses</a>.</p>
<h2>Not for sharing</h2>
<p>Containing a variety of <a href="http://www.bbc.co.uk/schools/gcsebitesize/science/21c_pre_2011/disease/diseaseresistancerev4.shtml">white blood cells</a>, human milk stimulates the development of the infant immune system while providing protection from germs. <a href="http://adc.bmj.com/content/84/5/381.full">Research</a> reveals that such transmission, however, opens up the potential for infection with HIV, syphilis, hepatitis and herpes, among other viruses, which can pass along with these cells.</p>
<p>This viral transmission, along with the risk of contamination with bacteria and toxins, creates a need for careful management of milk sharing <a href="http://www.bmj.com/content/350/bmj.h1485">and selling</a>. The nutrient and bioactive compounds are affected by the mother’s consumption of food, drink, medicines and illicit drugs. The presence of toxins and contaminants are introduced by a mother’s environmental exposure, as well as during expression and storage of the milk. Expressing and pasteurising milk <a href="http://ajcn.nutrition.org/content/96/3/544.full.pdf+html">changes its composition</a> which can reduce or even eliminate some bioactive components. </p>
<p>Such impacts make oversight crucial for babies fed with another mother’s milk, but also mean a careful approach is needed by those adults who think human milk might hold medicinal value. While a liquid gold, awareness of the risks as well as the benefits of human milk is crucial, both for adult and infant consumers.</p><img src="https://counter.theconversation.com/content/57913/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Steele 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>Most people are aware of the benefits of breastmilk, but few are aware of the risks.Sarah Steele, Queen Mary University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/465162015-08-24T19:46:07Z2015-08-24T19:46:07ZBreast milk is best for new babies but it’s not the ‘pure’ food we thought<figure><img src="https://images.theconversation.com/files/92770/original/image-20150824-16450-gjlkcj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Breastfeeding reduces the risk of infections in early life.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/kongharald/13055969114/">Harald Groven/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>A Harvard University researcher <a href="http://www.theaustralian.com.au/higher-education/chemicals-build-up-in-breast-milk/story-e6frgcjx-1227492004488">last week suggested</a> western women stop breastfeeding after a couple of months to reduce the risk of passing potentially harmful toxins on to their infants via breast milk. </p>
<p>But while babies may receive chemicals and allergens in breast milk, it doesn’t mean breastfeeding is unsafe. For most women, breast milk is the best food for new babies. </p>
<h2>Benefits of breast milk</h2>
<p>Breastfeeding is the natural way to feed human infants. After all, infant formula is made with cow’s milk, and our babies are not little cows. The <a href="http://www.who.int/topics/breastfeeding/en/">World Health Organization (WHO)</a> recommends:</p>
<blockquote>
<p>Exclusive breastfeeding … up to six months of age, with continued breastfeeding along with appropriate complementary foods up to two years of age or beyond.</p>
</blockquote>
<p>These guidelines are estimated to save up to <a href="http://www.who.int/features/factfiles/breastfeeding/facts/en/">800,000 lives a year</a> in low-income, developing countries.</p>
<p>The first breast milk, known as colostrum, contains antibodies, live immune cells and anti-bacterial proteins and is very important for the new <a href="http://www.sciencedirect.com/science/article/pii/S0271531702003731">baby’s immune system</a>. </p>
<p>When a baby is born, the immune system is immature and the baby is at risk of contracting infections, especially respiratory viral infections. Breastfeeding reduces the risk of infections in early life and may reduce the risk of long-term diseases such as asthma, excess weight and obesity, and type 2 diabetes. </p>
<p>There is increasing evidence that vaccinating pregnant women against infections that threaten infant’s lives, such as whooping cough and influenza, may be the best way of protecting very young infants against these diseases. The precise mechanism underlying this protection is not known, but the immunological benefits of colostrum are likely to be involved.</p>
<p>But while the protection breastfeeding confers on infants in low-income developing countries against death from lower respiratory illnesses is indisputable, the same situation does not exist in high-income developed countries. </p>
<p>Some women are not able to breast feed, for reasons that are beyond the scope of this article, and the current focus on breastfeeding in countries such as Australia can leave these <a href="http://finch.com.au/books/guilt-free-bottle-feeding">women feeling guilty</a> that they have “failed” their babies.</p>
<h2>Is breast always best?</h2>
<p>Breast milk is produced by the mother’s body and, as such, is subject to the condition of her body. Infections such as HIV can be passed to infants via breast milk. </p>
<p>However, the <a href="http://www.who.int/features/factfiles/breastfeeding/facts/en/">WHO breastfeeding guidelines</a> suggest that that HIV-infected women should breast feed, provided that they are on adequate anti-retroviral treatment. Indeed, substantial progress has been made in high-prevalence countries such as <a href="http://www.avert.org/prevention-mother-child-transmission-pmtct-hiv.htm">South Africa</a> in reducing infant HIV infection while allowing the benefits of breastfeeding.</p>
<p>There is no doubt that breast milk is also likely to contain the same range of external or “xenobiotic” substances that exist in the mother’s body, including many prescribed and illicit drugs and environmental chemicals. </p>
<p>We used to think that that the placenta protected the developing fetus from maternal exposures and that breast milk was a “pure” and uncontaminated substance. Unfortunately neither of these beliefs is true. For practical purposes, the developing fetus is exposed to what the mother is exposed to and the breastfeeding infant is exposed to contaminants in the mother’s body. </p>
<h2>Chemicals and allergens</h2>
<p>Since the “chemical revolution” of the mid-to-late 20th century, hundreds of thousands of chemicals have been introduced into use with minimal to <a href="http://www.scientificamerican.com/article/the-great-chemical-unknown/">no testing to demonstrate their safety</a>. </p>
<p>The Centres for Disease Control and Protection in the United States monitor the population for <a href="http://www.cdc.gov/exposurereport/">212 environmental chemicals</a> and report that almost all Americans have these chemicals in their body; many of which, especially those that are soluble in fat, are likely to pass into breast milk. </p>
<p>There is no such population biomonitoring program in Australia. Many of the environmental chemicals have activities that mimic hormones and are collectively known as <a href="http://www.who.int/ceh/publications/endocrine/en/">endocrine-disrupting chemicals</a>. </p>
<p>One of the most controversial recently is <a href="http://www.thelancet.com/pdfs/journals/landia/PIIS2213-8587%2813%2970105-0.pdf">bisphenol-A</a>, which has been banned from products designed for babies in several countries but not in Australia. </p>
<p>A new report from a group of Danish and American researchers investigated levels of <a href="http://www.environmentalhealthnews.org/ehs/news/2015/aug/breastfeeding-baby-health-chemicals-endocrine-disruption">water- and stain-proofing chemicals</a>, known as perfluorinated alkylate substances, or PFASs, in children from the Faroe Islands. The babies who were exclusively breastfed had levels 20-30% higher, which gradually fell after weaning. </p>
<p>While data on this class of chemicals is new, the problem is not. Breastfed infants receive “doses” of many chemicals from their mother, including flame retardants, pesticides, plasticizers, and many long-lived persistent chemicals that are no longer in use.</p>
<p>It is not only chemicals that can pass into breast milk. Food proteins are also likely to be present and can increase the risk of food allergy. The <a href="http://www.allergy.org.au/images/stories/aer/infobulletins/2010pdf/ASCIA_Infant_Feeding_Advice_2010.pdf">infant feeding guidelines</a> of the Australasian Society of Clinical Immunology and Allergy encourages breastfeeding but also state that early introduction of solid foods, around four to six months of age, may help prevent food allergy.</p>
<h2>Benefits and risks</h2>
<p>Does the fact that babies receive chemicals and allergens in breast milk mean that breastfeeding is unsafe?</p>
<p>No, it clearly does not. While the chemicals in breast milk can be associated with adverse health effects, there is not a good understanding of what levels of such chemicals are unsafe or when, if ever, the potential adverse effects outweigh the benefits of breastfeeding. Balancing the pros and cons of breastfeeding would not be a trivial undertaking and, to my knowledge, has not been attempted. </p>
<p>There is a relatively new methodology, known as <a href="http://www.ehjournal.net/content/7/1/61">integrated environmental health impact assessment</a> that could be used to tackle this complex issue. This methodology is designed to incorporate the complexities of real world problems and to include views of stakeholders in framing the assessment scenario and in interpreting the results. </p>
<p>In the case of breastfeeding, this assessment would need to include views from a wide cross section of health care professionals, toxicologists and the general public. The results of such assessments would also be specific to the location in which they were undertaken, with potentially different conclusions reached in low-income and high-income countries.</p>
<p>The bottom line is that breast milk is the best food for new babies but that it is not the “pure” food it was assumed to be. For the vast majority of women and babies, breastfeeding, provided that it is possible, is best. </p>
<p>At this stage, it is not possible to provide accurate advice to Australian women about when, if ever, breastfeeding should be limited because of increased risks posed by chemical levels in the milk. Further research in this area is definitely needed.</p><img src="https://counter.theconversation.com/content/46516/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Sly 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>A Harvard University researcher last week suggested western women stop breastfeeding after a couple of months to reduce the risk of passing potentially harmful toxins on to infants via breast milk.Peter Sly, Director, Children’s Health and Environment Program and World Health Organization Collaborating Centre for Children’s Health and Environment, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.