There are health benefits to babies from being breastfed, including that breast milk contains hundreds of microbial species which are transmitted to the baby. There are also health benefits to the mother, including a lower risk of breast cancer and ovarian cancer. In addition, a multicenter study in the United States found that breastfeeding lowers the mother's risk of type 2 diabetes over the next 30 years - by up to 47%.
In general: the study found that the longer a woman breastfeeds, the lower her risk of developing type 2 diabetes. Thus one can say that breastfeeding has a "protective" effect for type 2 diabetes. From Medical Xpress:
In a long-term national study, breastfeeding for six months or longer cuts the risk of developing type 2 diabetes nearly in half for women throughout their childbearing years, according to new Kaiser Permanente research published Jan. 16 in JAMA Internal Medicine. "We found a very strong association between breastfeeding duration and lower risk of developing diabetes, even after accounting for all possible confounding risk factors," said lead author Erica P. Gunderson, PhD, MS, MPH, senior research scientist with the Kaiser Permanente Division of Research.
Women who breastfed for six months or more across all births had a 47 percent reduction in their risk of developing type 2 diabetes compared to those who did not breastfeed at all. Women who breastfed for six months or less had a 25 percent reduction in diabetes risk.
Dr. Gunderson and colleagues analyzed data during the 30 years of follow up from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a national, multi-center investigation of cardiovascular disease risk factors that originally enrolled about 5,000 adults aged 18 to 30 in 1985 to 1986, including more than 1,000 members of Kaiser Permanente Northern California.The new findings add to a growing body of evidence that breastfeeding has protective effects for both mothers and their offspring, including lowering a mother's risk of breast and ovarian cancer.
The long-term benefits of breastfeeding on lower diabetes risk were similar for black women and white women, and women with and without gestational diabetes. Black women were three times as likely as white women to develop diabetes within the 30-year study, which is consistent with higher risk found by others. Black women enrolled in CARDIA were also less likely to breastfeed than white women.
"The incidence of diabetes decreased in a graded manner as breastfeeding duration increased, regardless of race, gestational diabetes, lifestyle behaviors, body size, and other metabolic risk factors measured before pregnancy, implying the possibility that the underlying mechanism may be biological," Gunderson said. Several plausible biological mechanisms are possible for the protective effects of breastfeeding, including the influence of lactation-associated hormones on the pancreatic cells that control blood insulin levels and thereby impact blood sugar.
This study included 1,238 black and white women who did not have diabetes when they enrolled in CARDIA, or prior to their subsequent pregnancies. Over the next 30 years, each woman had at least one live birth and was routinely screened for diabetes under the CARDIA protocol, which included diagnostic screening criteria for diabetes. Participants also reported lifestyle behaviors (such as diet and physical activity) and the total amount of time they breastfed their children.
Breastfeeding a baby. Credit: Wikipedia Commons, Anton Nossik.