The longer a woman breastfeeds, the less likely she will develop metabolic syndrome over time, even if she has a history of gestational diabetes, according to the results of a prospective study that followed almost 1,400 women for 20 years.
Having breastfed for more than 1 month was associated with a 39%-46% lower incidence of metabolic syndrome (depending on duration of breastfeeding) among women with no history of gestational diabetes, and with a 44%-86% lower incidence among those with gestational diabetes.“The findings indicate that breastfeeding a child may have lasting favorable effects on a woman's risk factors for later developing diabetes or heart disease,” the lead author, Erica P. Gunderson, Ph.D., said in a statement released by Kaiser Permanente. The study was published online, [doi.org/10.2337/db09-1197]), and will appear in print in Diabetes in February.
Their findings did not appear to be caused by differences in weight gain, physical activity, or other health behaviors, but less abdominal fat and higher levels of high-density lipoprotein were characteristic of women who did not develop metabolic syndrome, added Dr. Gunderson of the division of research, epidemiology and prevention at Kaiser Permanente, Oakland, Calif.
The study followed 1,399 women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study, who were aged 18-30 years when they were enrolled, had never delivered a baby, and did not have metabolic syndrome at baseline. Of these women, 704 had at least one singleton live birth in 1986-2006, including 84 who had gestational diabetes; over 20 years, 120 cases of metabolic syndrome were diagnosed among these women. The overall incidence of metabolic syndrome was 12.0 cases/1,000 person years. The incidence was significantly higher among those who had been diagnosed with gestational diabetes during pregnancy, than those who had not (22.1 cases/1,000 person years, compared with 10.8 cases/1,000 person years.)
The study was funded by the National Institutes of Health.