Breastfeeding dates back to an extinct early human species that lived about two million years ago, according to new research out of Mount Sinai.
An international team of researchers at Mount Sinai discovered breastfeeding patterns of an extinct early human species by looking at the two million-year-old teeth. The research, published in the July edition of Nature provides more insight into the evolution of human breastfeeding which is considered a critical aspect of human development by doctors and scientists around the world. While researchers know the duration and exclusivity of nursing are important to the health of humans many aspects of nursing are still shrouded in mystery.
The scientists, relying on a tech-heavy method developed at Mount Sinai, were able to analyze teeth from Australopithecus africanus, which is an early human ancestor that lived two to three million years ago in South Africa. The A. Africanus had both human and apelike features. Using the teeth, the researchers were able to reconstruct the A. Africanus diet. The growth patterns of the teeth allowed the scientists to conclude that barium, which is found in milk, was in the teeth over time, providing a glimpse into nursing and dietary patterns.
Americans Don't Breastfeed as Long as Thier Extinct Counterparts
The researchers determined the A. Africanus breastfed for as long as a year and then may have fallen back to breastfeeding during six monthly cycles because of a lack of food. In America, a large number of moms, 57.6%, who begin breastfeeding last six months while that declines to 35.9% for those who last a year. Less than 50% of infants were exclusively breastfed for the first three months of their lives while only 25% were exclusively breastfed for the first six months.
"Seeing how breastfeeding has evolved over time can inform best practices for modern humans by bringing in evolutionary medicine. Our results show this species is a little closer to humans than the other great apes which have such different nursing behaviors," one of the study's first authors, Christine Austin, PhD, Assistant Professor of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai and member of Mount Sinai's Institute for Exposomic Research said in a press release highlighting the results of the research. "These are important findings from an evolutionary perspective because humans have long childhoods and short breastfeeding periods while apes have longer breastfeeding periods than humans do."
According to Austin, scientists remain in the dark as to why or when humans made the change and what impact that has on breastfeeding, agriculture, and industrialization as well as the health of moms and their babies.