Infant tooth reveals Neandertal breastfeeding history

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    Breastfeeding has always remained an integral part of the very species. However, the evolution of breast-feeding in humans has been decoded via a fossilized tooth of a Neanderthal child, thus solving the mystery behind how long the primitive mothers breast-fed their children.

    The analysis that was conducted using the barium concentration in different layers of tooth enamel revealed that the eight year-old Neanderthal, living about 100,000 years ago and whose extraordinarily well preserved remains were found in Belgium’s Scladina Cave, had breastfed exclusively for seven months and weaned after 14 months. The findings gain significance for overcoming the “recall bias” that has hampered research into how breastfeeding helps protect babies from infections, diabetes and sudden infant death syndrome.

    The discovery is also important in the context it would be lead to opening up of new avenues of research into human health and the evolution of living and extinct mammals. It has already revealed that Neanderthals could have had breastfeeding habits very similar to people today.

    Speaking about the discovery that was jointly undertaken by Australian and US researchers and published in the journal Nature, Dr Christine Austin, lead author and a post-doctoral fellow at the University of Sydney’s dental faculty, said: “Barium is higher in breast milk compared with prenatal exposure because the placenta is restricting movement of the barium across to the foetus.

    It may be noted that Barium levels in teeth have in other research been shown to be higher during breastfeeding in human children, dropping during weaning, and then again after the conversion to solid food. The mineralisation of barium in human tooth enamel already starts in the second trimester of pregnancy, when the immature teeth are still in the jawbone.

    During the analyses the researchers had initially used naturally shed teeth from human children and captive macaque monkeys in whom breastfeeding habits were carefully documented and then applied the technique to the ancient molar of a young Neanderthal. It was then concluded that the Neanderthal child was exclusively breastfed for at least seven months, and then breastfeeding was supplemented for another seven months.

    “Comparing the breastfeeding habits of humans, primates and Neanderthals can shed light on our evolutionary history. People are trying to find out the life history of our ancestors or hominid species – they want to look at when species replaced other species or when they diverged and one way of defining species is development. Humans differ from other primates in that we wean relatively early despite having long childhoods. “If we can work out that Neanderthals had a much earlier weaning time or a longer childhood compared to another hominid species then we can say that’s when they diverged and this is where humans have gotten this type of development from,” said Dr Austin.

    “One application is that we know that breastfeeding can be linked to health outcomes with children so if we can take these teeth and see precisely how long breastfeeding went for, we can more accurately link that to the health outcomes and find out how much breastfeeding might reduce that risk,” says Austin.

    Dr Manish Arora, Study co-author, at the Institute of Dental Research at Westmead Millennium Institute, while maintaining that since the tests were done with only one Neanderthal sample and it would be reckless of us to say this would be the norm for all Neanderthals, said : “We look forward to this technique being applied to more Neanderthal samples so that a more reliable consensus on weaning patterns in Neanderthals may be made.

    Apart from disclosing the breast feedings habits of the primitives, the study has also suggestion pertaining to the mystery behind the disappearance of the Neanderthals 30,000 years back, even as the Home sapiens flourished.