A study presented at a meeting of the American Heart Association in Chicago says dark chocolate may help prevent heart attacks and strokes.

The study, presented by lead author Diane Becker, was designed to test the effectiveness of aspirin therapy and subjects were told to give up chocolate, among other foods, The Baltimore Sun reported Wednesday.

However, rather than throw out results from subjects who cheated on their diets, Becker and her team analyzed data from the 139 patients who cheated — out of a total 1,200 subjects — and found that the clotting time for participants who consumed chocolate was significantly slower than those who followed the dietary rules. Becker said the platelet activity slowed further for those who consumed larger amounts of chocolate.

There was a major difference between those who ate chocolate and those who didn’t, she said.

Increasing the time it takes for clots to form in diseased vessels is highly effective in reducing myocardial infarction (heart attacks) and cardiac death, Becker said.