A study has found that prolonged breastfeeding is linked to higher intelligence, longer schooling and greater earnings as an adult.

Share on Pinterest The study suggests that breastfeeding can lead to benefits in adult life such as increased educational attainment and income.

The study, published in The Lancet Global Health, followed 3,493 infants born in Pelotas, Brazil. After an average of 30 years, the researchers measured their IQs and collected further information about their educational achievement and income.

“The effect of breastfeeding on brain development and child intelligence is well established, but whether these effects persist into adulthood is less clear,” says lead author Dr. Bernardo Lessa Horta of Federal University of Pelotas in Brazil.

“Our study provides the first evidence that 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.”

In the short-term, breastfeeding is known to reduce the prevalence of infectious diseases and mortality from them among infants. Exclusive breastfeeding is commonly recommended for the first 6 months after birth, to be continued alongside solid foods until at least the age of 1 year.

The Mayo Clinic describe breast milk as “the gold standard for infant nutrition” as it contains the right balance of nutrients for the baby while boosting its immune system.

Many previous observational studies involving breastfeeding have been limited due to social patterning. Mothers that breastfeed for longer durations have typically held high socioeconomic positions, and their improved access to health care may lead to overestimating the health benefits of breastfeeding.

While previous studies have been criticized for this potential confounding factor, the authors of the new study address this issue.

“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 explains.