Breast milk even more beneficial for baby if mother exercises regularly, finds study

By Dr. Ananya Mandal, MDJun 29 2020

A new study from the Ohio State University Wexner Medical Centre shows that if breastfeeding mothers exercise regularly, they may end up providing more beneficial breast milk. Exercise is known to benefit individuals in various ways, and this new study shows that there are probably more advantages to exercising than previously known. The study is published in the latest issue of the journal Nature Metabolism.

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Breastfeeding mothers and exercise

Exercise has been recommended throughout pregnancy, as well as post-pregnancy. This not only reduces the risk of excessive weight gain, obesity, and overweight during pregnancy and after but also protects from diabetes and heart disease. Exercising regularly also strengthens muscles and prevents complications.

Exercise in breastfeeding mothers

This new study reveals that even moderate exercise in pregnant mothers can lead to a rise in levels of a compound in their breast milk that could benefit their baby. The baby has a significant advantage of lowered risk of diabetes, obesity, and heart disease when they grow up, find the researchers.

Researchers explain

Lead researcher Kristin Stanford, a researcher at The Ohio State Wexner Medical Center's Diabetes and Metabolism Research Center explained that this is not the first time that a study has shown that a mother who exercises provides benefits to her baby. She said, "We've done studies in the past that have shown that maternal exercise improves the health of offspring, but in this study, we wanted to begin to answer the question of why." Explaining why they conducted this study, she added, "Because there is evidence that breast milk plays a major role, we wanted to isolate the effects of breast milk on offspring health."

There were two parts of this study – on experimental animals and on humans.

Lab mice and breast milk effects

For the first part of the study, Stanford and colleagues collaborated with researchers from the University of California, San Diego, Arkansas Children's Nutrition Center, and the Joslin Diabetes Center. They included lab mice in their study. The mice pups born of mice mothers that were mostly sedentary were fed breast milk from mice mothers that were active during their pregnancy. Another set of pups from physically active mothers also received their mother's milk. The experiment mimicked all babies feeding on breast milk of physically active mothers.

Results were surprising, say the researchers. The babies from sedentary mothers who were fed milk from active mother mice had the health benefits which were seen in the biological babies of the active mothers. Because the physically active mice mothers passed on the benefits to both their own babies as well as foster babies of sedentary mothers, the benefits were proven to be passed down via breast milk and not genes. These babies fed on milk from active mice mothers were all found to have a lower risk of heart disease, obesity, etc.

Effects of exercise on pregnant and postpartum women

In the second part of the study, the team included 150 pregnant mothers and postpartum mothers (who had recently given birth) and provided them with activity trackers. The physical activity of these mothers was tracked using these devices.

Breast milk from the mothers was chemically analyzed. Results revealed that mothers who moved more (showing up as more number of steps on the activity tracker) had raised levels of a compound called 3SL in their breast milk.

3SL in breast milk

The researchers believe that this compound 3SL is the crucial factor in providing health benefits to the baby. Stanford, who is also an associate professor of physiology and cell biology at Ohio State's Dorothy M. Davis Heart and Lung Research Institute, explained, "The increase in 3SL were not necessarily related to exercise intensity, so even moderate exercise like a daily walk is enough to reap the benefits."

She recommended exercise for all, saying, "Exercise is also great for your overall health during and after pregnancy, so anything you can do to get moving is going to benefit both you and your baby."

What about women who cannot exercise or cannot breastfeed?

Researchers added that a significant number of women cannot breastfeed or develop complications during pregnancy and after giving birth, which makes it difficult for them to move around or exercise. If the 3SL compound could be isolated, they explain, it would be beneficial for these babies. Babies who cannot breastfeed, for example, could be provided with this compound in formula, the team says.

Stanford said, "This human milk oligosaccharide had a significant impact on offspring healthy. Being able to add this into formula could provide benefits for babies when women aren't able to breastfeed."