Eating chocolate may decrease risk of irregular heartbeat

A study published in the journal Heart suggests that consuming moderate amounts of chocolate may significantly lower the risk of being diagnosed with atrial fibrillation (AF)—a common and dangerous type of irregular heartbeat.

The study included 55,502 men and women participating in the Danish Diet, Cancer, and Heath Study. Researchers considered study participants’ body mass index, blood pressure, and cholesterol, which were measured at the time participants were recruited, between December 1993 and May 1997. They also looked at participants’ health conditions, including high blood pressure, diabetes, or cardiovascular disease, and data on their diet and lifestyle, from questionnaires.

Diagnoses of AF were identified from the Danish National Patient Register. There were 3,346 cases of AF among the study participants over a 13.5-year follow-up period. Compared with those who ate a 1-oz serving of chocolate less than once per month, men and women who ate one to three servings per month had a 10% lower rate of AF; those who ate one serving per week had a 17% lower rate; and those who ate two to six servings per week had a 20% lower rate. The benefit leveled off slightly with greater amounts of chocolate consumption, with those eating one or more servings per day having a 16% lower AF rate. Results were similar for men and women.

“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,” said Elizabeth Mostofsky, instructor in the Dept. of Epidemiology at Harvard Chan School, a postdoctoral fellow at Beth Israel Deaconess Medical Center, and lead author of the study.

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