Eating one piece of dark chocolate a day could prevent heart disease and help diabetes sufferers by reducing blood sugar and insulin levels, scientists have discovered.
Scientists found that chocolate increases “good” cholesterol when between 200 and 600 milligrams a day is consumed.
The benefits depend on the amount of cocoa taken, making plain chocolate better than white or milk varieties.
In the study experts examined the cardiometabolic health of 1,139 volunteers who consumed chocolate flavanols in 119 different trials.
Authors who orchestrated the randomised controlled trials (RCTs) claimed the study shows the “urgent need” for more trials to improve understanding of the short-term benefits.
Author Dr Simin Liu, professor and director of the Centre for Global Cardiometabolic Health at Brown University, USA, said: “Our meta-analysis of RCTs characterises how cocoa flavanols affect cardiometabolic biomarkers, providing guidance in designing large, definitive prevention trials against diabetes and cardiovascular disease in future work.”
None of the studies were designed to test directly whether cocoa consumption leads to reduced cases of heart attacks or type two diabetes.
Graduate student Xiaochen Lin, who worked with Dr Liu on the study, added: “We found that cocoa flavanol intake may reduce dyslipidemia (furred arteries), insulin resistance and systemic inflammation, which are all major subclinical risk factors for cardiometabolic diseases.”
The study, published in the Journal of Nutrition, was funded by the American Heart Association, National Heart, Lung and Blood Institute and Mars.
Miss Lin said: “The treatment groups of trials included in our meta-analysis are primarily dark chocolate – a few were using cocoa powder based beverages.
“Therefore the findings from the current study apparently shouldn’t be generalised to different sorts of chocolate candies or white chocolates, of which the content of sugar/food additives could be substantially higher than that of dark chocolate.”
The authors concluded: “Our study highlights the urgent need for large long-term RCTs that improve our understanding of how the short-term benefits of cocoa flavanol intake on cardiometabolic biomarkers may be translated into clinical outcomes.”