Researchers investigate link between breast milk and obesity

To better understand obesity, University scholars are looking to many infants’ first source of nutrition: breast milk.

Sally Samaha

A University of Minnesota study aims to better understand infant and child obesity by focusing on breast milk.  

Researchers working on the Mothers and Infants Linked for Healthy Growth — or MILK — study analyze the connection between breast milk’s fat content, along with other factors, and obesity in what researchers say is one of the nation’s largest breast milk composition studies.

“It’s possible that one of the ways we are getting early-onset obesity in this country is by having obese moms who [have] factors in their milk that could be putting their babies at risk for obesity,” said Ellen Demerath, University School of Public Health professor and principal investigator of the study, who has partnered with a professor at the University of Oklahoma to conduct the study.   

While many other breast milk studies focus on topics like brain development and IQ, Demerath’s 5-year study — set to end in 2019 — looks at some of the lesser-known aspects of breast milk composition.

“What hasn’t been looked at very much is the quality of breast milk,” Demerath said. “There are at least 600 to 1,000 different chemicals in breast milk that have not been adequately studied. So the aim of the MILK study is to understand more about the qualities in breast milk, and we are studying that in the context … of obesity.”

Participating mothers between 21 and 44 years old are recruited in the second trimester of their pregnancy. This year, researchers looked for participants at the Minnesota State Fair in the University’s Driven to Discover building. 

Researchers collect samples of breast milk from each mother when their babies are one month old and again at three months. Researchers measure the babies’ growth and body fat at one, three and six months, said study coordinator Laurie Foster.

Researchers use these measurements plus questionnaires and information about the mothers’ heights and weights to analyze the link between breast milk and obesity, she said. 

The next stage of the research will follow those babies until they are 3 years old, Foster said. 

University graduate student Regina Marino, who managed and organized breast milk samples for the study, said she hopes the study will give the public an even better understanding of breast milk’s benefits.

“Hopefully this study will shed some light and answer questions like why is breast milk so good for the babies’ growth and development,” Marino said.

And some other researchers want the study’s findings to influence how people of all ages, not just pregnant women, make choices.

“It would be so great if boys and girls could grow knowing that their own behaviors and choices and diet [aren’t] just about them but about their own children, if they choose to have children,” Demerath said. “What you do for your body isn’t just about you, it’s also about the next generation.”