Breast really is best

More evidence that breast-feeding babies changes their lives for the better

FOUR extra points of IQ, an extra year’s education and a significantly enhanced income at the age of 30. Those are the benefits of having been breast-fed, according a study just published in Lancet Global Health by Bernardo Horta of the Federal University of Pelotas, in Brazil, and his colleagues.

Previous research has suggested that breast-feeding has beneficial long-term effects. But Dr Horta’s work is particularly persuasive because it looks at adults rather than children and teenagers, and because it contradicts the suggestion that social class is a confounding variable, with rich mothers tending to breast-feed more than poor mothers do.

The participants in the study were among a group of Brazilians born in Pelotas in 1982. Following a cohort like this through their lives is an established method of medical research. It lets doctors test hypotheses that retrospective examination, relying on memory, cannot address reliably. In 2012 and 2013 Dr Horta managed to track down 3,493 members of the cohort whose diet as babies, including their consumption of breast milk, had been recorded at the time, ask them some questions, and give them an IQ test.

Comparing those who, as babies, had been breast-fed for less than a month with those who had been so fed for more than a year, Dr Horta found the latter’s IQ was 3.76 points higher than the former’s and that they had attended school for 0.91 years longer. The income data were slightly more complicated. Those breast-fed for over a year had incomes 15% higher than those suckled for less than a month, but those breast-fed for six to 12 months did even better, at 55%. These effects, moreover, were unaffected by a family’s income at the time a study participant was born.

The reasons for this are not known for certain, though it is easy to speculate. Human milk has, presumably, been optimised for human nutrition by evolution. The social contact involved in suckling may also have an effect. But the underlying cause is less important than the result. As Winston Churchill once said, “there is no finer investment for any community than putting milk into babies.” Add the word “mother’s” in front of “milk”, and the returns on that investment get finer still. –http://www.economist.com/news/science-and-technology/21646646-more-evidence-breast-feeding-babies-changes-their-lives-better-breast-really-best?fsrc=scn/fb/te/pe/ed/breastreallyisbest