Breastfeeding May Reduce Diabetes Risk

Lactation History Linked to Less Metabolic Syndrome

Medically Reviewed by Louise Chang, MD on December 03, 2009

Dec. 3, 2009 -- There is more evidence that breastfeeding benefits moms as well as their babies.

Breastfeeding was shown to significantly lower a woman’s risk for developing metabolic syndrome in a study reported today by researchers with Kaiser Permanente.

The longer the women in the study breastfed, the more protection they seemed to derive.

Insulin Resistance, Belly Fat

Metabolic syndrome is a cluster of risk factors linked to both diabetes and heart disease, including elevated blood pressure, insulin resistance, and belly fat.

The new study is one of the most rigorously designed trials ever to explore the impact of breastfeeding on such risk factors.

Researchers examined data on 704 women who were followed for two decades, starting before their first pregnancy.

Because the women were enrolled in a larger heart disease risk study, the researchers had information on wide range of health and lifestyle factors. None of the women had metabolic syndrome at enrollment, but 120 developed the condition during the 20 years of follow-up.

In the population as a whole, breastfeeding for longer than nine months was associated with a 56% reduction in risk for developing metabolic syndrome during the follow-up period.

In women who developed gestational diabetes during one or more pregnancies, the risk reduction was 86%.

Gestational diabetes is a major predictor of type 2 diabetes. Women who develop diabetes during pregnancy have a fourfold greater risk for developing type 2 diabetes, lead researcher Erica P. Gunderson, PhD, tells WebMD.

“Our study is the first to examine lactation and metabolic syndrome in women with this risk factor,” she says. “Our findings indicate that this very vulnerable group may benefit from breastfeeding.”

Breastfeeding for as little as a month or two appeared to convey some benefit, but not as much as longer lactation.

The study was funded by the National Institutes of Health and will be published in the February, 2010, issue of the journal Diabetes.

Breastfeeding May Lower Belly Fat

There is some evidence that women who breastfeed lose pregnancy weight quicker and that they lead healthier lifestyles than new mothers who do not breastfeed.

The Kaiser researchers adjusted for lifestyle factors such as exercise level and smoking in their study.

And Gunderson says overall weight differences did not explain the protection breastfeeding appeared to convey in this study.

But there is a suggestion that breastfeeding is specifically linked to a reduction in belly fat. Central obesity, or belly fat, and insulin resistance are two important risk factors for metabolic syndrome.

“Belly fat seemed to be disproportionably increased due to pregnancy, and perhaps lactation helps women lose this abdominal fat,” she says. “This is something we need to look at more closely.”

The study is not the first to suggest that women who breastfeed have a lower risk for developing diabetes years later.

In 2005, researchers from Harvard Medical School came to the same conclusion after analyzing data on 160,000 female nurses enrolled in two health studies.

The research suggested that each year of breastfeeding is associated with a 15% reduction in diabetes risk within the next 15 years.

Lead researcher Alison M. Stuebe, MD, told WebMD at the time that a woman with two children could potentially lower her risk for developing diabetes by almost a third by following the advice of child health experts and breastfeeding each child for a year.