New Research Traces Breastfeeding Benefits 10 Years Into Childhood

If you or someone close to you has breastfed, you’ve likely heard no shortage of advice (both solicited and unsolicited) about the many ways breastfeeding helps babies’ developing brains and bodies. Until recently, however, experts weren’t sure how long these positive effects continue to impact child development after breastfeeding ends. 

According to a new study in Nature Pediatric Research led by Children’s Hospital Los Angeles scientists, the benefits of breastfeeding stretch even farther into a child’s development than experts previously thought. The researchers’ statistical analysis of more than 7,000 U.S. children identified associations with positive brain and body development 10 years into childhood. 

Vidya Rajagopalan, PhD, a researcher in the Division of Cardiology at CHLA, and two other researchers from CHLA and the Keck School of Medicine of USC set out to ask: What long-term benefits of breastfeeding can be traced in children’s brains and bodies years later?

Data from a landmark study empowers deeper, broader analysis

To ensure their analysis was truly representative across the U.S. population, the researchers needed to get their hands on as much data as possible.

They used a public dataset including brain and body scans, socioeconomic history and family/health history of 7,511 kids who participated in The Adolescent Brain Cognitive Development (ABCD) Study. ABCD is the largest long-term study of brain development and child health in the U.S. funded by the National Institutes of Health (NIH).

“What’s really cool about this particular data set is that it’s not biased toward people living in any particular part of the nation,” says Dr. Rajagopalan. “The kids involved in this study have a variety of characteristics and backgrounds. It’s also not biased toward families that feel one way or the other about breastfeeding.” 

Breastfeeding connects to brain development, healthy BMI

Dr. Rajagopalan and team conducted a statistical analysis to explore the long-term benefit of breastfeeding across two key areas: brain development and healthy weight.

First, they measured the impact of breastfeeding on several brain growth metrics and found that longer breastfeeding duration correlated to higher grey matter surface area.

“Gray matter areas are like the computing centers of our brains,” Dr. Rajagopalan explains. “We know from past scientific studies of the developing brain that higher grey matter surface area correlates to better performance on cognitive tasks.”  

“As much as I love to see the brain benefits of breastfeeding, we recorded an even greater connection between breastfeeding and healthy weight,” Dr. Rajagopalan adds. Children who breastfed longer were likely to have healthy body mass index (BMI) and height-to-weight ratios, lowering their overall risk of later obesity. 

The researchers measured these effects across three different breastfeeding duration categories: 0-3 months, 3-6 months and 12 months and longer. The magnitude of the benefit increased the longer the child was breastfed, with the greatest benefit to children who were breastfed 12 months and longer.

Tracing breastfeeding benefits across income levels

What’s tricky about most breastfeeding benefit studies, Dr. Rajagopalan explains, is that it’s often difficult to separate breastfeeding duration from socioeconomic status.

A variety of factors tie into why families can breastfeed for longer (or at all). The reality for many lower-income parents is that the logistics of returning to work don’t allow for breastfeeding, especially for moms who work hourly roles. This is often why research reflects breastfeeding benefits primarily across higher-income families.

To ensure they could measure the effects of breastfeeding across socioeconomic levels, the researchers added an additional layer to their analysis: A mapping tool that categorizes socioeconomic conditions of neighborhoods relative to the regional cost of living. “It gave us a normalized measure across the country so we could compare different areas based on the same set of features,” says Dr. Rajagopalan.

The analysis confirmed that breastfeeding provides brain and body benefits across both higher and lower socioeconomic levels. Additionally, the researchers surfaced one particularly fascinating finding: The effect of breastfeeding on brain-body development was even stronger in families of lower socioeconomic status.

Any duration will do

While the researchers observed the greatest brain-body benefit in children who were breastfed for 12 months and longer, Dr. Rajagopalan encourages parents not to adopt an all-or-nothing mindset around breastfeeding, with a reminder that any time spent breastfeeding has a positive effect on a child’s brain and body.

“We always hear the phrase ‘breastfeeding is the most natural thing,’ but it’s also not always intuitive,” says Dr. Rajagopalan. “I still tell the families that a fed baby is best.”

Her recommendations: “As long as you can and whatever you can give your child is a benefit. I know 12 months seems like a daunting amount of time for a lot of women who are breastfeeding. Maybe it’s better to think about what can get you to the next month, and then the next month after that.”

“This kind of research is not to shame anyone for their choice, but to uncover more about human development and understand what we can do better to give our children the best chance at growth,” Dr. Rajagopalan emphasizes. “If that includes breastfeeding, then as a country we need to develop stronger health and social policies to make breastfeeding more accessible to everyone.”