Breastfeeding Lowers Type 2 Diabetes Risk in Women with Gestational Diabetes, Study Finds
Women who had gestational diabetes, which is when diabetes only manifests during pregnancy, have a lower risk of developing type 2 diabetes if they breastfeed for a certain amount of time.
The researchers at Kaiser Permanente set out to examine the relationship between breastfeeding and type 2 diabetes risk in women with gestational diabetes. Every year, about five to nine percent of all pregnant women - about 250,000 - will developed high blood glucose. Years after childbirth, women with gestational diabetes have a seven time greater risk of developing diabetes.
In the study, "Study of Women, Infant Feeding and Type 2 Diabetes after GDM Pregnancy" (SWIFT Study), the researchers recruited more than 1,000 Kaiser Permanente participants from Northern California. All of the participants were diagnosed with gestational diabetes from 2008 to 2011.
The researchers tracked the women's blood sugar level via oral glucose tolerance tests, which were done at six to nine weeks post delivery, at one year after delivery and then at two years after delivery. At the two-year point, 12 percent of women had developed type 2 diabetes.
The team found that women who used formula exclusively starting at six to nine weeks after birth were two times more likely to develop type 2 diabetes than women who started off breastfeeding exclusively.
Risk of type 2 diabetes fell when women continued to breastfeed after two months and up to two years. For example, breastfeeding for at least 10 months straight reduced risk of type 2 diabetes by 57 percent when compared to breastfeeding only for two-months or less.
"Both the level and duration of breastfeeding may offer unique benefits to women during the post-delivery period for protection against development of type 2 diabetes after gestational diabetes pregnancy," lead author Erica P. Gunderson, PhD, MPH, MS, epidemiologist and senior research scientist at the Kaiser Permanente Division of Research, said in the news release. "These findings highlight the importance of prioritizing breastfeeding education and support for women with gestational diabetes as part of early diabetes prevention efforts by health care systems."
The researchers did not find a cause and effect relationship but they explained why breastfeeding could lower risk.
"Lactation gives the insulin-producing cells in the body a rest because they don't have to make so much insulin to lower blood glucose," Gunderson explained. "Breast-feeding uses up glucose and fat in the blood because those nutrients are transferred from the bloodstream into the breast tissue for milk production."
The study's findings were published in the Annals of Internal Medicine.