Can a decade of dark chocolate protect your heart?

Chocolates are pictured during the opening of the Nestle Chocolate Centre of Excellence in Broc near Fribourg September 7, 2009.

LONDON (Reuters) - A scientific study likely to stir the souls of chocoholics has suggested that eating dark chocolate every day for 10 years could reduce the likelihood of heart attacks and strokes in some high-risk patients.

A team of researchers from Australia used a mathematical model to predict the long-term health impact of daily dark chocolate consumption in 2,013 people with a condition known as metabolic syndrome, which puts them at high risk of heart disease.

The team found that in the best case scenario - with no patient missing any daily portions - the treatment could potentially avert 70 non-fatal and 15 fatal heart attacks or strokes per 10,000 people over 10 years.

The model also suggested that mounting effective "dark chocolate prevention strategies" might cost an individual just 25 pounds ($40) a year.

The researchers, whose work was published in the British Medical Journal on Friday, stressed the protective effects have only been shown for dark chocolate containing at least 60 to 70 percent cocoa - not for milk or white chocolate. This is probably due to higher levels of flavonoids in dark chocolate.

But experts not involved in the study urged caution.

"Recommendations for daily consumption of dark chocolate ... will certainly get people with metabolic syndrome excited, but at this point these findings are more hypothetical than proven, and the results need real-life data to confirm," said Kenneth Ong at the Brooklyn Hospital Center in the United States.

"I suspect that consuming dark chocolate every day for 10 years may have unintended adverse consequences," he added. "The additional sugar and caloric intake may negatively impact patients in this study, who are overweight and glucose intolerant to begin with."

All participants in the study, led by Christopher Reid at Monash University in Melbourne, had high blood pressure and metabolic syndrome, but had no history of heart disease or diabetes and were not on blood pressure lowering medication. ($1 = 0.6497 British pounds)

(Reporting by Kate Kelland; Editing by Andrew Heavens)