Breastfeeding for Longer Linked to Higher IQ

Want a happier, healthier, wealthier and more intelligent child? (Who doesn't?) Keep up the breastfeeding. New study links longer nursing to higher incomes and IQs

Breastfeeding for Longer Linked to Higher IQ Mila Supinskaya/Shutterstock

We always knew breast was best for a healthier baby, but new scientific evidence has revealed that breastfeeding for as long as a year could also make your baby smarter.

A recent study published in The Lancet Global Health journal found that breastfeeding a baby for longer is linked to increased intelligence, longer schooling and higher earnings in adulthood—whatever the parents' social class.

"Prolonged breastfeeding 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," said study author Dr Bernardo Lessa Horta of the Federal University of Pelotas in Brazil.

Dr Horta and his colleagues analyzed data from nearly 6,000 infants born in Pelotas, Brazil in 1982. Information on how much they nursed was collected in early childhood and then participants were given an IQ test around the age of 30 and asked about education and income levels.

"What is unique about this study is the fact that, in the population we studied, breastfeeding was not more common among highly educated, high-income women, but was evenly distributed by social class," Dr Horta explained. "Previous studies from developed countries have been criticized for failing to disentangle the effect of breastfeeding from that of socioeconomic advantage."

The research found that the levels of adult intelligence, education and earnings increased the longer a child was breastfed up to a year. For example, an infant who had been breastfed for a year achieved a full four IQ points, had almost a year more schooling and, on average, earned a third higher income than those who had breastfed for less than a month.

Dr Horta attributes the spike in adult intelligence and career success to the child's prolonged exposure to the long-chain saturated fatty acids (DHAs) found in breast milk, which are essential for brain development. This suggests the amount of milk consumed played a role in the results.

Dr Erik Mortensen from the University of Copenhagen in Denmark, an author of an accompanying journal article, says although the study doesn't necessarily point to cause and effect, the association it made linking breastfeeding and intelligence is strong.

"The study suggests that the effects of breastfeeding on cognitive development persist into adulthood, and this has important public health implications," he said.

Need some help with keeping that milk flowing for 12 months? Check out Fit Pregnancy's guide to breastfeeding for the whole first year.