Turns Out, Breast-Feeding’s Benefits Last Way Longer Than We Thought

A new study reveals that breast-feeding can boost IQ, income, and success well into adulthood.

(Photo: Getty Images)

Mar 18, 2015· 2 MIN READ
Samantha Cowan is an associate editor for culture.

The breast is best—and a study out of Brazil has shown that’s true in ways we didn’t understand before.

The global health community has long promoted the positive effects of breast-feeding on child health, but new research conducted at the Federal University of Pelotas is shedding light on how the benefits of breast milk can extend far beyond infancy and the developmental years.

Researchers tracked more than 3,000 people from birth and for up to three decades. Those who were breast-fed the longest had a higher IQ and higher earnings, according to the findings published this week in The Lancet Global Health. Earlier studies had noted a correlation between breast-feeding and higher IQ scores, but this is the first to measure the effects well into adulthood.

“Our study provides the first evidence that prolonged breast-feeding not only increases intelligence until at least the age of 30 years but also has an impact both at an individual and societal level by improving educational attainment and earning ability,” study author Bernardo Lessa Horta told The Guardian.

The study began in 1982 and selected children from different socioeconomic backgrounds; factors such as the mother’s education level, child’s birth weight, and family income were also incorporated into the final figures.

Horta was especially interested in determining whether a correlation exists between brain development and nursing, believing the polyunsaturated fatty acids in breast milk contribute to brain growth—and thus higher levels of intelligence and earning potential. He found that it does: Children who were breast-fed for a year or longer added close to four points to their IQ score and were also more likely to have completed an additional year of education compared with children who breast-fed for just a few months. The longer a child was breast-fed, the greater the benefits: Monthly salaries were a third higher for those who breast-fed the longest.

The World Health Organization estimates that approximately 800,000 lives would be saved annually if every child were breast-fed within an hour of being born, were breast-fed exclusively for the first six months of life, and continued to be breast-fed for two years. The immediate benefits of breast-feeding are particularly apparent in developing countries—breast milk protects against diarrhea and respiratory infections that can result from formula being mixed with unsanitary water.

Children in developed countries also benefit from breast-feeding, showing lower rates of obesity and diabetes. Still, many women are unable to breast-feed for a variety of reasons, including finding it painful, being forced to return to work shortly after giving birth, or not having support, such as from a lactation specialist. Society doesn’t make it easy either. One Walmart store publicly shamed a woman for trying to nurse her baby in one of its aisles, and other moms have challenged expectations that women should breast-feed in bathrooms.

The study’s large sample size and consistent figures certainly indicate a positive trend. However, for women who are unable to breast-feed, health professionals have reported that a variety of other factors can impact a child’s aptitude.

Horta and his team are hopeful the study will encourage more women to breast-feed and offer more support systems for those attempting to do so. And maybe it will put an end to shaming women trying to breast-feed their children in public too.