Many new mothers breastfeed to give their infants the immunity-boosting and nutritional benefits breast milk provides. But breastfeeding is good for mothers, too. It reduces the risk of some cancers, helps them recover more rapidly from pregnancy and lowers the risk of cardiovascular disease. A recent study highlighted yet another plus for breastfeeding moms — a lower risk of type 2 diabetes.
Type 2 diabetes affects nearly two percent of women of childbearing age (20-39 years) in the U.S. It is even more common among African American women, affecting nearly five percent of those of childbearing age.
The researchers followed a group of over 1200 African American and white women over a 30-year period, tracking their breastfeeding histories and their metabolic health. The study was unique because instead of relying on self report of diabetes by the participants, they measured the women's biochemical parameters at baseline and seven more times during the study period, giving them objective evidence of the presence or absence of diabetes.
The longer a woman breastfed, the greater her protection.
The results were very encouraging: the risk of developing type 2 diabetes was reduced by 25 percent for mothers who breastfed for less than six months. Mothers who breastfed for six months or more nearly halved their risk. They enjoyed a 47 percent risk reduction.
In other words, the longer a woman breastfed, the greater her protection from type 2 diabetes. Women with gestational diabetes who breastfed their infants also enjoyed a reduced risk of developing type 2 diabetes. This is especially significant because, according to the Centers for Disease Control, up to nine percent of pregnant women may develop gestational diabetes and up to 10 percent of mothers are diagnosed with type 2 diabetes just after the pregnancy. Even women who don't immediately develop diabetes have a 35 to 60 percent chance of developing type 2 diabetes within 10 to 20 years.
Why does breastfeeding reduce type 2 diabetes risk? The researchers offer several possible explanations. Breastfeeding requires that a large load of glucose be diverted to the mammary glands to synthesize milk, reducing glucose levels. It also changes hormone levels, including increasing prolactin, and this may act to preserve pancreatic cell function. Insulin-making beta cells increase in size and functioning with the mobilization of fatty tissues needed for breast milk production.
The authors believe the costs of such programs will be more than offset by the decrease in chronic diseases in women. They write, “It is also imperative to improve breastfeeding practices to interrupt the transgenerational transmission of obesity-related diseases. Lactation is a natural biological process with the enormous potential to provide long-term benefits to maternal health, but has been underappreciated as a potential key strategy for early primary prevention of metabolic diseases in women across the childbearing years and beyond.”
The study is published in JAMA Internal Medicine.