In addition, researchers report in The Journal of the American Medical Association, it appears that women's risk of type 2 diabetes declines with each additional year they breastfeed in their lives.

"For right now, I think the bottom line is breastfeeding isn't just good for babies; it's also good for mothers," says lead author Alison Stuebe, a clinical fellow in maternal-fetal medicine at the Brigham and Women's Hospital in Boston.

The American Academy of Pediatrics recommends that women breastfeed each baby for at least a year, but relatively few U.S. women breastfeed that long.

Researchers from the Centers for Disease Control and Prevention found that in 2003, only about 36% of U.S. babies were breastfed to some extent at 6 months old. By their first birthday, only about 17% were still getting some breast milk — well below the government's "Healthy People 2010" goal of 25%.

Most research about breastfeeding's effect on mothers' long-term health has focused on breast cancer, says co-author Karin Michels, associate professor of obstetrics, gynecology and reproductive biology at Harvard Medical School. But women need to breastfeed for more than a year to cut their breast cancer risk, Michels says.

The researchers analyzed data from about 157,000 female nurses who answered questions about how many pregnancies they'd had and how long they breastfed each child. The nurses also answered a variety of questions related to lifestyle and personal and family medical history.

Women who breastfed for longer periods were less likely to have a family history of diabetes and, on average, had a lower body mass index upon enrollment in the study. But even after accounting for those possible confounding factors, the researchers still found a connection between breastfeeding and lower diabetes risk.

Among women who had given birth in the previous 15 years, the risk of diabetes fell about 15% with every additional year of breastfeeding, the authors write. Breastfeeding one child for a year was associated with a greater risk reduction than breastfeeding two children for a total of a year.

Breastfeeding had no effect on diabetes risk in women who'd had gestational diabetes, perhaps because they have a much higher risk of type 2 diabetes, the authors write.

Stuebe speculates that breastfeeding might reduce diabetes risk because of its lasting beneficial effect on insulin resistance and glucose tolerance. She notes that women burn about 500 calories a day breastfeeding — the same as running 4 or 5 miles.

- More articles on Breastfeeding
- More articles on Diabetes

Reference Source 129
November 24, 2005