Consuming up to one piece of chocolate a day may protect against a common irregular heart rhythm called atrial fibrillation, based on a recent study published in the British medical journal Heart.
Conducted from 1993–1997, the Danish Diet, Cancer and Health Study explored the impact of diet and lifestyle on health outcomes in Danish adults. The study included more than 55,500 participants, all of which underwent medical exams and completed questionnaires about their health, diet and lifestyle.
Using national registries, researchers then tracked which patients developed atrial fibrillation over the next 13.5 years. Atrial fibrillation is a common type of irregular heart rhythm that affects up to 6.1 million Americans.
Participants were 50–64 years old at the start of the study; more than half were women.
Over the study period, more than 3,300 participants developed atrial fibrillation. However, researchers found that moderate chocolate consumption was associated with significantly lower risk for atrial fibrillation.
Analysis showed that participants consuming 1–3 servings of chocolate a month were 10% less likely to develop atrial fibrillation than those consuming chocolate less than once a month. Additionally, participants consuming 1–7 servings of chocolate a week had 16–20% lower risk for developing atrial fibrillation than participants consuming chocolate less than once a month.
In this study, one serving of chocolate was defined as 30 grams—the equivalent of about 150 calories—and included both milk and dark chocolate.
While authors note that the study does not prove that chocolate directly reduces risk for atrial fibrillation, it does reinforce the health benefits of moderate chocolate consumption. The cocoa component of chocolates contain flavanols and antioxidants that help fight inflammation and disease. It’s likely that in reasonable amounts, chocolate may help protect against a number of conditions, such as heart disease, heart attack and atrial fibrillation.