Poor blood vessel function is recognized as an early stage indicator of cardiovascular diseases such as atherosclerosis. For more than 20 million Americans living with diabetes, these vascular impairments can eventually lead to heart disease and stroke, the cause of death for two-thirds of those who suffer from diabetes. Despite good diabetes control and medical treatment, adults with the disease often continue to experience vascular dysfunction. This has led scientists on a search for novel medical or nutritional options to improve the health and quality of life for people with diabetes.
Scientists funded by Mars, Inc. have determined that a cocoa flavanol-rich beverage made using the Mars Cocoapro® process experienced a 30 percent improvement in measured vessel function at the completion of a 30-day trial. Consuming a cocoa flavanol-rich beverage daily may have the potential to positively impact the blood vessel dysfunction associated with diabetes, they say.
The flavanol in cocoa is not to be confused with another compound spelled flavonol, which is found in some onions, grapes and green tea.
In this study, the impact of both immediate and regular consumption of a flavanol-rich cocoa drink on vascular function in diabetic adults was investigated. In the first part of this study, medically-treated adults with type 2 diabetes – a population known to have impaired blood vessel function, putting them at higher risk for cardiovascular disease – drank a well-characterized and standardized cocoa beverage made using the Mars Cocoapro® process that contained different flavanol levels, ranging from 75 to 963 milligrams, and had their blood vessel function measured for several hours following consumption. The researchers found a positive correlation between the flavanol dose consumed and immediate improvements in FMD (flow mediated dilation, a measure of vessel health, i.e. the ability of a vessel to relax).
In a subsequent controlled 30-day, double-masked clinical trial, adults with established diabetes who were medically controlled, drank either a flavanol-containing cocoa beverage or a low-flavanol control three times a day. The cocoa beverages contained either 25 milligrams of cocoa flavanols (control) or 321 milligrams of cocoa flavanols (treatment) and were matched for calories, nutrients and other cocoa compounds such as theobromine and caffeine.
Beyond the immediate improvements in FMD following flavanol consumption, participants experienced sustained improvements in blood vessel function upon consuming the flavanol-containing cocoa over a period of 30 days (30 percent increase in FMD between day one and 30).
“We were pleasantly surprised by the magnitude of impact of cocoa flavanols on vascular function in these diabetic adults,” said Mars, Incorporated Chief Science Officer Harold Schmitz, PhD. “If a dietary intervention with cocoa flavanols can produce such profound, sustained improvements in vascular function on-top of standard medication in a population with increased risk for cardiovascular diseases, the implications with regard to health and quality of life could be remarkable.”
While this study is very promising, the researchers indicate that larger trials are necessary to fully demonstrate the clinical relevance of flavanol-rich foods in the context of cardiovascular health and disease.
Contrary to statements often made in the popular media, the collective research demonstrates that the cardiovascular effects of cocoa flavanols are independent of general "antioxidant" effects that cocoa flavanols exhibit in a test tube, outside of the body.
While research aimed at studying the potential role of cocoa flavanols in the context of blood vessel and circulatory function continues, a number of previously published studies already suggest that the consumption of cocoa flavanols can have important beneficial effects on the function of the body’s network of blood vessels.
The body of research not only suggests that cocoa flavanols may provide a dietary approach to maintaining cardiovascular function and health, but also points at new possibilities for cocoa flavanol-based interventions for vascular complications associated with cognitive performance, skin health and age-related blood vessel dysfunction.
Article: Balzer J, Rassaf T, Heiss C, Kleinbongard P, Lauer T, Merx M, Heussen N, Gross HB, Keen CL, Schroeter H, Kelm M. Sustained benefits in vascular function through flavanol-containing cocoa in medicated diabetic patients: A double-masked, randomized, controlled trial. Journal of the American College of Cardiology. 2008.