Breastfed babies achieve more in life, have higher IQs and make more money, study finds

Brazilian study of 6,000 babies from all backgrounds since 1982 finds those who breastfed were more intelligent, spent longer in education and earned more.

Breastfed babies are more likely to turn into well-educated and higher-earning adults, according to a major long-term study.

Researchers in Brazil have followed nearly 6,000 babies from birth for the past three decades, enabling them for the first time to get an idea of the long-term effects of breastfeeding. Nearly 3,500 of them, now 30-year-old adults, accepted an invitation to be interviewed and sit IQ tests for the purpose of the study. Those who had been breastfed proved to be more intelligent, had spent longer at school and earned more than those who had not been. And the longer they were breastfed as a baby, the better they tended to be doing.


Doctors have known for years that infants who are breastfed perform better on intelligence tests in childhood, but the new study, published in The Lancet Global Health, makes the strongest link yet to IQ in adulthood.

The children who were breastfed also stayed in school about a year longer and earned more money when they grew up — an amount equal to about $104 extra each month.

The researchers corrected for other factors that could influence IQ, such as the child’s birth weight, mother’s education level and family income, and concluded breastfeeding makes a significant difference.

Previous studies that suggested breastfeeding may boost adult IQ focused on higher-income families and researchers weren’t sure the results would hold up in a more diverse population, but the Brazil study found the connection is real. What’s less clear is the reason why.

“The question is always, is it the breast milk itself or is it the breastfeeding that conveys the benefit?” Phillips said. “I think it’s both. We do know breast milk has a number of nutrients that support the developing brain and the nervous system. On the other hand, the communication and bonding that happens during the breastfeeding process changes the brain physically, it makes neurons connect with one another. That increases IQ and it also boosts confidence, which translates into achievement later in life. So I think are a number of factors that are contributing here.”

Children who are breastfed tend to enjoy a number of other health benefits. They are less likely to suffer from a variety of gastrointestinal and respiratory infections, asthma, diabetes and other conditions. Studies have also shown they have better thinking and memory skills and score higher on cognitive, language and motor development tests as toddlers, and that’s why mothers should try to breastfeed for as long as possible, with the goal to nurse for at least six months, according to the World Health Organization.