Heart disease is a leading killer in the United States. High blood pressure, high cholesterol, obesity, and diabetes are common factors that contribute to the development of the disease. For premenopausal women, hormones appear to have some protective affect on the heart and blood vessels. This hormonal effect is evident in the increased rates of heart disease in postmenopausal women compared to premenopausal women. Women also have hormonal fluctuations during pregnancy and while breastfeeding, and there is growing evidence that these hormones may also affect a mother’s long-term heart health.
The department of medicine at the University of Pittsburgh wanted to determine if there was a relationship between breastfeeding and the development of heart disease later in life. The study, published in the Journal of Obstetrics and Gynecology, found that women who breastfed their babies had lower risk of high blood pressure, diabetes, high cholesterol, and cardiovascular disease than women that were pregnant and did not breastfeed.
The study examined information collected from 139,681 postmenopausal women in the Women’s Health Initiative (WHI) Study. All the women included had reported at least one birth. The data from the WHI Study included the number of births each women had, if the women breastfed their babies, and if so, for how long. Any amount of breastfeeding seemed to be beneficial, but when compared to women who were pregnant but never breastfed, women that breastfed for a lifetime total of 12 months or more had:
The rate of obesity, a risk factor for all of the health conditions listed above, was similar between the two groups. There are many other factors that may increase heart disease risk factors such as age, income, education, lifestyle choices, and family history. When researchers accounted for all of these factors there was still a significant relationship between increased breastfeeding and risk factors for heart disease.
The information used in this study was collected in an observational study. The researchers observed and did not interfere with any other factors that may contribute to heart disease. Despite best efforts, researchers cannot always account for all such factors in this type of study. As a result the researchers are unable to prove a cause-and-effect relationship, but their results do suggest a connection may exist.
Exactly how breastfeeding may provide heart protection is not clear from this study, but hormonal changes are thought to be a key factor. Nevertheless, breastfeeding has long been known to provide numerous health benefits for the baby. Now it appears that the same may be true for the mother. If you are pregnant, plan on breastfeeding your child, unless your doctor advises otherwise.
Schwarz EB, Ray RM, Stuebe AM, et al. Duration of lactation and risk factors for maternal cardiovascular disease.Obstet Gynecol.2009 May;113(5):974-82.
Last reviewed July 2009 by Richard Glickman-Simon, MD Last Updated: 7/13/2009