News article

Breastfeeding linked with lower risk of maternal heart attacks

February 14, 2009

Lifetime breastfeeding of at least 2 years is associated with a reduced risk of heart attacks and coronary artery disease, according to a new large study published in this month’s issue of the American Journal of Obstetrics and Gynecology. Using data from over 89,000 women from the Nurses’ Health Study, the study found that mothers who had total of at least 2 years of lifetime breastfeeding had 37% lower risk of heart attacks from coronary artery disease (CAD) compared to mothers who had never breastfed, even adjusting for common potentially confounding risks.

Even when the study’s findings were adjusted for potentially confounding factors of obesity, parental history, and lifestyle factors such as smoking, these women still had 23% lower risk of CAD compared to mothers who had never breastfed. CAD, also known as coronary heart disease, consists of atherosclerosis of the arteries that nourish the heart muscle, and it is the most common cause of heart attacks and angina.

Dr. Alison Stuebe, assistant professor of Obstetrics and Gynecology at the University of North Carolina, led the study. Stuebe, formerly of Brigham and Women’s Hospital in Boston, has served on the board of the Massachusetts Breastfeeding Coalition. She is also lead author of a 2006 study that showed longer duration of breastfeeding is associated with decreased risk of maternal type 2 diabetes.

“Breastfeeding is good for mothers and babies,” Stuebe said. “This study provides additional evidence that successful breastfeeding impacts health risks across two generations.”

Previous research on humans and animals suggested that breastfeeding may affect the metabolism of the lipids implicated in atherosclerosis. Breastfeeding women are known to have higher levels of HDL cholesterol (the so-called “good cholesterol”) and higher levels of triglycerides, which can be harmful. Other data has found that breastfeeding reduces blood pressure and heart rate. Elevated blood pressure also contributes to atherosclerosis and CAD.

The American Academy of Pediatrics recommends breastfeeding for at least the first year of an infant’s life, and most other major medical organizations recommend breastfeeding for the first two years. The finding imply a substantial public health benefit if more mothers breastfed according to recommendations. Currently, only about 21% of US infants are still breastfeeding at 1 year, according to the Centers for Disease Control and Prevention.

The abstract of the study is available on the PubMed web site, and the article is available on the AJOG website (with an accompanying editorial).