Can breastfeeding for longer make a child smarter?

There are many scientific studies showing that breastfeeding offers health benefits to infants. Many of these reports focus on tangible benefits, like breast milk’s ability to help babies ward off allergies or reduce their risk of developing gastrointestinal issues. But quality research demonstrating how breastfeeding can affect an infant’s brain has been far more difficult to produce. Previous studies on the topic have made connections, but they didn’t account for many other factors that influence a child’s development, like his mother’s intelligence, socioeconomic status, home environment during key developmental milestones or if he was raised with homecare vs. daycare.

In addition, many of these studies focused only on whether baby was “ever breastfed” or “never breastfed.” By ignoring an entire population of children raised on both breast milk and formula—or researching how much time they spent receiving either— these studies fail to truly define the potential role breastfeeding plays in a child’s future cognitive development.

To better explore the issue, researchers from Boston Children’s Hospital’s Division of Newborn Medicine recently conducted a study on the possible ways breast milk and intelligence are related, while accounting for several of the factors ignored in other studies. In doing so, the team has produced the most complete analysis of the subject to date.

Mandy Belfort, MD, MPH

“In research of this nature, it would be impossible to try to measure and account for all the variables that determine the role breastfeeding plays in a child’s cognitive development, but we went to lengths to do so, and to isolate its true effects,” says lead author Mandy Belfort, MD, MPH, whose research is largely focused on the relationship between infant growth and nutrition and healthy development. “These findings paint a more accurate picture of how the two are intertwined than any other study we’ve seen.”

The team reviewed extensive breastfeeding information of over 1,000 children and mothers, and then measured how well each child performed on receptive language testing at 3 years, and intelligence tests at 7. Even after accounting for many variables, Belfort’s team found that infants who had been breastfed for longer had higher vocabulary scores at 3 and demonstrated better verbal and nonverbal intelligence scores at 7, with each extra month of breastfeeding providing a small additional benefit. (Researchers did not find breastfeeding leads to improvements in visual motor skills, memory or learning.)

“Our findings clearly demonstrate that children who were breastfed longer had higher scores,” Belfort says.  “But it’s also important to note that these improvements per month of breastfeeding were small. At an individual level, I don’t think the differences uncovered in our study will make a large difference in how a single child develops. But when thinking about this issue from a larger, societal standpoint, it could be extremely important in improving overall cognitive development of children.”

And while Belfort’s study certainly adds to research proving breastfeeding’s health benefits, the researcher is quick to point out that the practice is by no means a requirement for parents looking to raise a smart, healthy baby. “Breastfeeding is one of many things parents can do to promote cognitive development in their infants, but it’s certainly not the only thing,” she says. “Turning off the TV and talking and reading to babies is very important and can make a big difference in their development as well. Regardless of which feeding practice you adhere to, an engaged parent will always be the most important factor in promoting a child’s future.”

“Regardless of which feeding practice you adhere to, an engaged parent will always be the most important factor in promoting a child’s future.”

Going forward, Belfort says more research on the effects of breastfeeding should be explored, including how maternal diet during breastfeeding effects development—a topic examined in her research, but an area she thinks requires additional study. But regardless of what future studies will reveal about breastfeeding, Belfort is hopeful this new data will help families currently wondering if, and especially for how long, they will breastfeed their children.

“Breastfeeding is an incredibly personal choice, and these findings are by no means telling people how to make that choice,” she says. “But I do hope this study is able to provide quality information for those people who are looking to make an informed choice, and will also justify greater support for people who are currently breastfeeding their babies.”