May 24 (UPI) -- Harvard researchers have found consuming moderate amounts of chocolate may lower the risk of atrial fibrillation, or AF, a common type of irregular heartbeat.
Previous research has shown that cocoa and cocoa-containing foods, especially dark chocolate -- with a higher cocoa content than milk chocolate -- have cardiovascular benefits due to their high content of flavanols.
Flavanols promote healthy blood vessel function, according to researchers.
Researchers at Harvard T.H. Chan School of Public Health and researchers in Denmark conducted a study of 55,502 men and women who participated in the Danish Diet, Cancer, and Health Study, which recruited participants from December 1993 to May 1997.
Participants body mass index, or BMI, blood pressure and cholesterol were measured at the beginning of the study along with information on health conditions, diet and lifestyle.
Researchers identified 3,346 cases of AF among the study participants over a 13 and a half-year follow-up.
Participants who ate two to six servings of chocolate per week had a 20 percent lower rate of AF, those who ate one serving per week had a 17 percent lower rate of AF and those who ate one to three servings per month had a 10 percent lower rate of AF.
"Our study adds to the accumulating evidence on the health benefits of moderate chocolate intake and highlights the importance of behavioral factors for potentially lowering the risk of arrhythmias," Elizabeth Mostofsky, instructor in the Department of Epidemiology at Harvard and postdoctoral fellow at Beth Israel Deaconess Medical Center, said in a press release.
The protective benefit of lower AF was moderated with greater amounts of chocolate consumed per day.
"Despite the fact that most of the chocolate consumed by the study participants likely had relatively low concentrations of potentially protective ingredients, we still observed a significant association between eating chocolate and a lower risk of AF -- suggesting that even small amounts of cocoa consumption can have a positive health impact," Mostofsky said.
The study was published in Heart.