Tuesday, March 27, 2007
Flavonoids are antioxidant compounds found in wine, green tea, fruits and vegetables that are associated with a strong inverse correlation with cardiovascular disease. Among common foods, flavonoids are found in highest concentration in ... wait for it ... cocoa and dark chocolate.
In a study sure to warm the cockles of one antipodian philosopher of my acquaintance, the Yale Prevention Research Center in Connecticut conducted a trial to assess whether the consumption of cocoa would provide any sustained benefits for endothelial function. Okay ... I don't really understand what that is, except that it involves the single-cell lining covering the internal surface of blood vessels and cardiac valves that can "sense" changes in hemodynamic forces and blood-borne signals and "respond" by releasing vasoactive substances. I think we can assume, however, that high endothelial function good, low endothelial function bad.
Specifically, the team measured the function of the brachial artery to relax and expand to accommodate increased blood flow (also know as flow mediated dilation, or FMD) in adults with a body mass index (BMI) between 25 and 35 kg/m2. In the randomized, single-blind, placebo-controlled crossover study, 45 subjects recruited from the general population of southwestern Connecticut were randomly assigned to one of the three consumption groups: eight ounces of either cocoa without sugar, cocoa with sugar or placebo. For six weeks, all participants underwent endothelial function testing, assessing FMD of the brachial artery using high frequency ultrasound before and after the daily cocoa or placebo consumption.Valentine Yanchou Njike, M.D., a co-investigator on the study, said "dark chocolate ingestion over a short period of time was shown to significantly improve endothelial function, leading our team to believe that greater benefit may be seen" when more extensive studies are done. Typically, the sciencey types have to play spoil sport:
While the findings from this study do not suggest that people should start eating more chocolate as part of their daily routine, it does suggest that we pay more attention to how dark chocolate and other flavonoid-rich foods might offer cardiovascular benefits.
My guess would be that the subjects were not told what the active material was supposed to be. They could have simply called it "a common foodstuff". Then the placebo group gets some other material with similar physical traits.