The analysis included data from eight studies with a total of 1.19 million women who gave birth for the first time when they were 24.6 years old on average. These women had an average of 2.3 births, and 82 percent of them said they breastfed their babies. Researchers followed these women for about a decade, starting when they were 51.3 years old on average to see whether a history of breastfeeding was associated with better heart health outcomes. Compared with women who didn’t breastfeed, those who did were 14 percent less likely to have coronary heart disease (clogged arteries that can lead to heart attacks) and 12 percent less likely to have a stroke. Breastfeeding was also associated with a 17 percent lower risk of dying from events like heart attacks and strokes. While the analysis wasn’t designed to examine why breastfeeding might have heart benefits, there are several possible explanations for this connection, says senior study author Peter Willeit, MD, a professor of clinical epidemiology at the Medical University of Innsbruck in Austria. “For instance, breastfeeding could facilitate a more rapid weight loss after delivery,” Dr. Willeit says. “This may be beneficial, as it is known that elevated weight is a risk factor for cardiovascular disease.” Beyond this, breastfeeding may also reduce the risk of metabolic disorders like high cholesterol and type 2 diabetes, which are risk factors for cardiovascular disease, Willeit says. Breastfeeding for a total of up to 12 months over a lifetime was associated with better heart outcomes, but researchers didn’t have enough long-term data on how longer cumulative durations of breastfeeding might benefit women. Researchers also lacked data on individual participants that might have helped them make more accurate assessments of how different durations of breastfeeding impact cardiovascular outcomes.
Breastfeeding Associated With Lower Fat Deposits
“The beneficial effects of breastfeeding on a woman’s cardiometabolic health are powerful,” says Erica Gunderson, PhD, a senior research scientist at the Kaiser Permanente Northern California Division of Research in Oakland, California. “Studies have shown that breastfeeding is associated with more favorable metabolic profiles but also with lower maternal fat deposits in the heart, liver, and belly many years post-delivery, which may potentially exert long-term cardiovascular health benefits,” Dr. Gunderson says. In a study published in June 2021 in The Journal of Clinical Endocrinology & Metabolism, breastfeeding was associated with significantly lower volumes of two types of body fat that are linked to heart problems: visceral fat, which packs in around the midsection, and pericardial fat, which collects on the outside of the heart. Another study published in January 2019 in the Journal of Hepatology examined data on 844 women who had given birth to at least one child. Those who breastfed for more than six months had half the risk of developing fatty liver compared with those who breastfed for less than one month or who didn’t breastfeed babies at all, the study found. Similarly, a study published in the Annals of Internal Medicine focused on more than 1,000 mothers who had what’s known as gestational diabetes, a form of the metabolic disorder that develops during pregnancy and increases the risk of type 2 diabetes later in life. Women who breastfed exclusively were half as likely to develop type 2 diabetes as those who didn’t breastfeed at all. An analysis published in October 2019 in JAMA Network Open examined the link between breastfeeding and type 2 diabetes in about 206,000 women and the connection between breastfeeding and high blood pressure in about 255,000 women. In this analysis, women who breastfed for 12 months or longer were 30 percent less likely to develop type 2 diabetes and 13 percent less likely to develop high blood pressure as women who had shorter durations of breastfeeding.
Post-Pregnancy Heart Health Regardless of Breastfeeding Status
Even though breastfeeding has heart health benefits, there’s a lot that women who don’t breastfeed can still do to help minimize their risk of developing or dying from cardiovascular disease, Willeit says. Prevention can start even before pregnancy. Preconception, women can focus on maintaining a healthy weight; eating lots of fruits, vegetables, and fiber; getting regular exercise, even if it’s just a daily 20-minute walk; reducing alcohol consumption; and not smoking, according to the American Heart Association (AHA). All this can lower the risk of cardiovascular disease whether or not women breastfeed their babies. And all of this advice still holds true during pregnancy, according to the AHA. Well in advance of their due date, expectant mothers should also try to get breastfeeding education and explore what support they may need if they want to breastfeed, Gunderson says. This might mean buying or renting a pump to express milk or finding a lactation consultant to help troubleshoot any issues with nursing that might crop up once their baby arrives. Support is especially crucial for women who are at a high risk for breastfeeding problems, including those who have obesity, diabetes, or high blood pressure, Gunderson says. “Increased breastfeeding support of women, particularly those with pregnancy complications immediately after delivery, may have long-term benefits of improving cardiometabolic health and reducing longer-term risk of cardiovascular disease outcomes later in life,” Gunderson says.
