Women who breastfed at least one child showed a 23 percent reduced risk of stroke compared to those who never breastfed, according to an observational study published Aug. 22 in the Journal of the American Heart Association.
The association was particularly strong for black women (48 percent reduced risk) and Hispanic women (32 percent reduced risk), which is important considering they suffer strokes in the U.S. at a disproportionately high rate compared to white women.
Stroke is the third-leading cause of death among Hispanic and black women in the U.S. Also, women experience about 55,000 more strokes annually than men, wrote lead author Lisette T. Jacobson, PhD, MPA, and colleagues.
“Whereas studies to date have largely focused on the protective effect of breastfeeding on cardiovascular risk factors, few studies have assessed whether breastfeeding protects against risk of stroke and whether this association differs by race/ethnicity,” the researchers wrote. “Because Hispanic and non‐Hispanic black women experience low breastfeeding rates and are at higher risk for stroke compared with non‐Hispanic white women, there is a need to examine this relationship so that future intervention programming may focus on specific populations that carry the largest health burden of stroke.”
Jacobson et al. analyzed data from 80,191 participants from the Women’s Health Initiative Study who had delivered at least one child. Participants were an average of 63.7 years old when they were recruited for the study and followed for a mean 12.6 years.
Fifty-eight percent of the mothers reported having breastfed. Among that group, 51 percent breastfed for at least six months, 22 percent breastfed for seven to 12 months and 27 percent breastfed for at least 13 months.
In addition to the stroke risk reductions associated with any amount of breastfeeding, Jacobson et al. found longer durations of breastfeeding further reduced the risk. Compared to those who never breastfed, doing so for six months was linked to a 19 percent reduced risk of stroke while breastfeeding for 13 or more months was associated with a 26 percent decline.
“Study results show an association and dose‐response relationship between breastfeeding and lower risk of stroke among postmenopausal women after adjustment for multiple stroke risk factors and lifestyle variables,” the researchers wrote. “Increasing public awareness of the potential impact of breastfeeding on maternal health outcomes later in life may assist in the support for, initiation, and continuation of breastfeeding for those at greatest risk.”
The observational nature of the study made it impossible to determine cause and effect. Women with health problems during pregnancy may have had trouble breastfeeding and been exposed to a greater stroke risk later in life due to those issues, the authors acknowledged.
“Breastfeeding for longer durations could be a marker for better health in general rather than specifically a risk factor for stroke,” Jacobson and colleagues said.
Also, the study contained a relatively low number of strokes—3.4 percent of participants experienced one during follow-up—and the researchers didn’t directly examine whether racial or ethnic differences in breastfeeding habits contribute to the established disparities in stroke rates.
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.