Daily consumption of dark chocolate can decrease cardiovascular events, such as heart attacks and strokes, in people with metabolic syndrome. Dark chocolate (containing at least 60% cocoa solids) is rich in flavonoids, which are known to have heart protecting effects. A team of researchers from Melbourne, Australia conducted the study in 2,013 people, who were already at high risk of heart disease.

All participants had high blood pressure and met the criteria for metabolic syndrome, but had no history of heart disease or diabetes and were not on blood pressure lowering therapy.

With 100% compliance (best case scenario), the researchers show that daily dark chocolate consumption could potentially avert 70 non-fatal and 15 fatal cardiovascular events per 10,000 people treated over 10 years.
Only non-fatal stroke and non-fatal heart attack were assessed in their analysis, and that the potential effects on other cardiovascular events, such as heart failure, are yet to be tested. Also be cautioned that, this has only been examined in short term studies and these protective effects have only been shown for dark chocolate (at least 60-70% cocoa), rather than for milk or white chocolate, probably due to the higher levels of flavonoids found in dark chocolate.