Eating dark chocolate every day for 10 years could reduce the incidence of such cardiovascular events as heart attacks and strokes in those with metabolic syndrome, a group of risk factors for heart disease and diabetes, according to an Australian study.

The investigators developed a mathematical model to predict the health effects and cost effectiveness of daily dark chocolate consumption over 10 years. They performed a Meta-Analysis of several studies involving 2,013 people with high blood pressure and who met the criteria for Metabolic Syndrome.

Cardioprotective effects have only been demonstrated for dark chocolate (defined as containing at least 60 to 70 percent cocoa solids), and not for milk or white chocolate.

Study participants had no history of heart disease or diabetes and were not on medication to lower their blood pressure.

The researchers showed that, when study participants ate dark chocolate faithfully every day, daily dark chocolate consumption could prevent 70 non-fatal and 15 fatal cardiovascular events per 10,000 people treated over 10 years.

Even when they ate dark chocolate only 8 out of every 10 days, the number of cardiovascular events prevented was 55 and 10 per 10,000 people treated over 10 years, and so could still be considered an effective intervention strategy.

Simply spending about $42 per person per year on prevention strategies involving dark chocolate consumption, including advertising, educational campaigns, or subsidizing the purchase of dark chocolate in high-risk populations, could, according to their model, produce a solid health benefit, the scientists said.

The authors pointed out that they only looked at the effects of dark chocolate consumption on the incidence of non-fatal stroke and non-fatal heart attack, and that its potential effects on other cardiovascular events, such as heart failure, need to be studied.

They also said that cardioprotective effects have only been demonstrated for dark chocolate (defined as containing at least 60 to 70 percent cocoa solids), and not for milk or white chocolate. This focus on dark chocolate may be due to the higher levels of flavonoids, the compounds that give chocolate its cardioprotective effects, found in dark chocolate.

The researchers concluded, however, that the blood pressure and cholesterol lowering effects of plain dark chocolate "could represent an effective and cost effective strategy for people with metabolic syndrome (and no diabetes)."

The cardioprotective effects of flavonoids in dark chocolate have previously been studied only in short-term studies. Further research is needed to determine an actual cause and effect relationship. How much dark chocolate should be eaten a day is also not clear from the study, so don't gorge, thinking more is better; it is likely not.

The investigators published their work in the British Medical Journal.