While 8 of 10 mothers breastfeed their newborns for a short time, the number plummets despite recommendations from experts, in part because milk production falls off.
Researchers investigating why that happens found that in women who are obese, inflammation may be the culprit.
Prior research has shown that when a person is obese, chronic inflammation starts in the fat and spreads to organs and systems throughout the body. And that inflammation may disrupt absorption of fatty acids from the blood into body tissues.
These fatty acids are the building blocks for the fats needed to feed a growing infant.
"Science has shown repeatedly that there is a strong connection between the fatty acids that you eat and the fatty acids in your blood,” said lead author Rachel Walker, postdoctoral fellow in nutritional sciences at Penn State University. "If someone eats a lot of salmon, you will find more omega-3s in their blood. If someone else eats a lot of hamburgers, you will find more saturated fats in their blood."
The study is among the first to examine whether fatty acids in blood are also found in breast milk, Walker said.
"For women who are exclusively breastfeeding, the correlation was very high; most of the fatty acids that appeared in blood were also present in the breast milk," she said in a university news release.
But for women with chronic inflammation who were struggling to make enough milk, that link was almost gone, Walker said.
"This is strong evidence that fatty acids are not able to enter the mammary gland for women with chronic inflammation," she added.
For this study, researchers analyzed blood and milk from a study conducted at Cincinnati Children's Hospital and the University of Cincinnati.
In the original study, researchers recruited 23 mothers who had very little milk despite efforts to stimulate production through frequent breast emptying; 20 mothers with moderate milk production; and a control group of 18 who breastfed exclusively.
Compared to the other mothers, those with very little milk had significantly higher rates of obesity and biological markers of systemic inflammation.
While milk and blood fatty acids were strongly linked in the control group, that was not true in the groups with moderate or very low milk production.
"Breastfeeding has innumerable benefits for both the mother and child, including lower risk of chronic disease for mom and lower risk of infections for baby," said study co-author Alison Gernand, associate professor of nutritional sciences at Penn State.
"This research helps us understand what might be happening in mothers with high weight status and inflammation, which down the road could lead to interventions or treatments that allow more moms that want to breastfeed to do so," Gernand said in the release.
The U.S. Centers for Disease Control and Prevention recommends breastfeeding exclusively for a baby's first six months. Just 25% of mothers do so, citing job pressures and a lack of social support as obstacles.
The findings were recently published in the Journal of Nutrition.
The U.S. Centers for Disease Control and Prevention has more on the importance of breastfeeding.
SOURCE: Penn State University, news release, Dec. 21, 2022