Reporting in this week’s Archives of Internal Medicine, researchers from the University of Pennsylvania compared the effects of eating chocolate on heart health among more than 1,200 older women. Using dietary questionnaires, researchers looked at how frequently the women ate chocolate and also looked at ultrasound images of their carotid arteries to see if there were any changes in artery thickness -- an indication of atherosclerosis, a condition in which the arteries harden and blood flow becomes impaired.
Chocolate consumption was divided into three groups: less than one serving per week, between one and six servings per week, and seven or more servings per week or eating chocolate every day. A serving of chocolate was defined as weighing between 25 and 50 grams (0.9 and 1.8 ounces) and containing between 5% and 15% of cocoa by weight.
A total of 47.6% of the participants ate chocolate less than once a week, 35.8% ate chocolate one to six times per week, and 16.6% of the group ate chocolate every day.
Researchers found that there were 158 atherosclerosis-related events among people who ate chocolate only once a week. There were 90 atherosclerotic events among people who ate chocolate one to six times per week and only 42 atherosclerotic events among people who ate chocolate seven or more times per week.
Researchers also conducted a secondary analysis among people who ate chocolate less than once a week and people who ate chocolate one to six times per week. They looked at hospital records and found that hospitalizations and deaths related to atherosclerosis were lower among people who ate chocolate one to six times per week. This group had a lower rate of ischemic heart disease, heart failure, and also fewer atherosclerotic plaques -- fatty blockages that reduce blood flow.
The cocoa found in chocolate is rich in flavonoids that have been associated with a reduced risk for cardiovascular disease. Although the researchers cautioned that this study did not evaluate whether there is a cause-and-effect relationship between eating chocolate and heart disease, they did suggest that eating chocolate regularly might help prevent atherosclerotic disease events requiring hospitalization. Researchers also questioned if chocolate may have a stronger effect on ischemic heart disease than on cerebrovascular disease.
There are several types of chocolate on the consumer market; one of the most popular forms in the U.S. is milk chocolate, which contains high amounts of fat. These latest study findings add to a growing body of research that links eating moderate amounts of chocolate -- particularly chocolate with high levels of cocoa -- to improved heart health. For example, a recent study from Sweden suggested that eating chocolate reduced the risk of heart failure in women.