"To the tantalizing delight of chocolate lovers everywhere a number of recent studies employing various methods have suggested that compounds in cocoa called flavanols could benefit cardiovascular health. Now a systematic review and metaanalysis of  randomized controlled trials RCTs of cocoa consumption reveals some further pieces of supporting evidence. The metaanalysis in the Journal of Nutrition an assessment of the combined evidence from all  RCTs focused on whether consumption of flavanolrich cocoa products was associated with improvements in specific circulating biomarkers of cardiometabolic health as compared to consuming placebos with negligible cocoa flavanol content. In all  volunteers were involved in these trials. Our metaanalysis of RCTs characterizes how cocoa flavanols affect cardiometabolic biomarkers providing guidance in designing large definitive prevention trials against diabetes and cardiovascular disease in future work said corresponding author Dr. Simin Liu professor and director of the Center for Global Cardiometabolic Health at Brown University who worked with epidemiology graduate student and lead author Xiaochen Lin. We found that cocoa flavanol intake may reduce dyslipidemia elevated triglycerides insulin resistance and systemic inflammation which are all major subclinical risk factors for cardiometabolic diseases. Liu noted some limitations in the trials. All studies were small and of short duration not all of the biomarkers tracked in these studies changed for the better and none of the studies were designed to test directly whether cocoa flavanol consumption leads to reduced cases of heart attacks or type  diabetes. But taking into account some of these heterogeneities across studies the teams metaanalysis summarizing data from  trials found potential beneficial effects of flavanolrich cocoa on cardiometabolic health. There were smalltomodest but statistically significant improvements among those who ate flavanolrich cocoa product vs. those who did not. The greatest effects were seen among trial volunteers who ate between  and  milligrams of flavanols a day based on their cocoa consumption. They saw significant declines in blood glucose and insulin as well as another indicator of insulin resistance called HOMAIR. They also saw an increase in HDL or good cholesterol. Those consuming higher doses saw some of the insulin resistance benefits and a drop in triglycerides but not a significant increase in HDL. Those with lower doses of flavanols only saw a significant HDL benefit. In general Lin said where there were benefits they were evident for both women and men and didnt depend on what physical form the flavanolrich cocoa product was consumed in dark chocolate vs. a beverage for example. The treatment groups of the trials included in our metaanalysis are primarily dark chocolate  a few were using cocoa powderbased beverages Lin said. Therefore the findings from the current study apparently shouldnt be generalized to different sorts of chocolate candies or white chocolates of which the content of sugarfood additives could be substantially higher than that of the dark chocolate. The authors therefore concluded Our study highlights the urgent need for large longterm RCTs that improve our understanding of how the shortterm benefits of cocoa flavanol intake on cardiometabolic biomarkers may be translated into clinical outcomes.    In addition to Lin and Liu the studys other authors are Isabel Zhang Alina Li from Brown University JoAnn Manson Howard Sesso and Lu Wang from Brigham and Womens Hospital. The authors acknowledge funding from the National Institutes of Health including the National Heart Lung and Blood Institute the American Heart Association and Pfizer. Coauthors at Brigham and Womens also noted receiving funding from Mars Symbioscience a research segment of Mars Inc. which makes chocolate products."