Calling all chocoholics: British researchers recruiting volunteers willing to eat a bar of chocolate daily for a year, guilt-free and all in the name of science.

The trial starting in June will explore whether compounds called flavonoids found in chocolate and other foods can reduce the risk of heart disease for menopausal women with type 2 diabetes, the researchers said on Monday.

"We are looking at a high risk group first," said Aedin Cassidy, a biochemist at the University of East Anglia, who will lead the study. "We hope there will be an additional benefit from dietary intervention in addition to the women's drug therapy."

Previous studies have suggested dark chocolate is rich in the beneficial compounds linked with heart health but experts note the high sugar and fat content of most commercially available chocolate might cancel out some of the advantages.

A host of other research has also shown dark chocolate appears to lower blood pressure, improve the function of blood vessels and reduce the risk of heart attack.

This has spurred companies such as Hershey Co and Lindt & Spruengli to market specific products containing dark chocolate. Mars Inc has introduced CocoaVia, a line of dark and premium chocolates that plays up such health advantages.

Cassidy said her team will also publish findings in the American Journal of Clinical Nutrition showing that flavonoids found in soy and cocoa appear to have the strongest effects of the compounds in reducing risk of heart disease.

The next step will be recruiting 150 women past menopause with type 2 diabetes. The researchers will look at whether the compounds help reduce blood pressure, cut cholesterol levels and improve the condition of arteries.

Half the women in the year-long study will eat a super-charged chocolate bar containing 30 grams of flavonoids found in soy, cocoa and other fruits and vegetables. The others will get chocolate without the active compounds.

The researchers hope the study could have implications for the wider population if results show significant benefits from the isoflavones contained in soy and epicatechin found in cocoa.

This could help doctors tailor advice to patients on the type and amount of foods to eat to reduce heart disease risk -- and it does not necessarily need to be chocolate, Cassidy said.

"If this trial works we will be able to give advice on a whole range of foods," Cassidy said. "People won't have to go around eating a specially designed chocolate bar."