The study, by researchers from University Dusseldorf, University of Reading and chocolate-maker Mars, gave test subjects drinks containing 450mg cocoa-derived flavanols, or a flavanol-free control, twice a day for a month, and measured their blood pressure, cholesterol and other vital signs at the start and end of the period.
In a departure from most previous flavanol studies, all the participants were healthy, having normal-range BMIs and no signs of cardiovascular disease.
Improved BP and cardio health
After a month, subjects taking the flavanol drink showed a mean fall in in-office blood pressure (BP) of 4·4/3·9 mmHg, which the authors said was comparable to BP falls demonstrated in other cocoa-flavanol studies, and “approaches the BP-lowering effect sizes observed by typical BP-lowering medications”.
Subjects also showed improved Framingham Risk Scores, which measure the 10-year cardiovascular risk of an individual, suggesting their long-term health was also improved. But researchers noted the short duration of the study meant more research was needed to confirm this.
The study was conducted by members of the Flaviola research consortium, a group funded by Mars as well as a grant of almost €3m from the European Union. Mars also provided the flavanol mixture used in the study.
No benefit from chocolate
As commonly noted in studies of cocoa-derived flavanols, although the compounds show beneficial effects, the benefit does not translate to the consumption of chocolate. Not only does chocolate’s high sugar, fat and calorie counts mitigate any positive effects of flavanols, but many of the most beneficial compounds may not be present in finished chocolate products.
“Different flavanols have different structures and behave differently inside the body. The mixture of these different flavanols varies from plant to plant and the type and mixture found in cocoa is unique, consisting predominantly of (-)-epicatechin and (+)-catechin. These compounds are, however, mostly destroyed during roasting and alkalization in the manufacture of chocolate,” said Marc Merx, chief physician at the Intensive Care Clinic for Cardiovascular and Internal Medicine at Robert Koch Hospital in Gehrden, and one of the study’s authors and co-ordinator for Flaviola.
When asked what alternative flavanol sources consumers can consider, Merx said: “Many other fruits and vegetables like apples, berries and grapes contain sources of flavanols, but not in the same quantity and mixture as in cocoa beans.
“While it is clear that the intake of 900mg per day resulted in the observed cardiovascular benefits in healthy people, it may well be that amounts lower than 900mg per day could also mediate similar benefits. Further research aimed at investigating a wider range of intake amounts is needed to answer this question,” he added.
He also noted that one of the reasons for the use of cocoa flavanols in the study is the standardised flavanol content of cocoa-derived test products.
Source: British Journal of Nutrition
Published online ahead of print, doi:10.1017/S0007114515002822
“Cocoa flavanol intake improves endothelial function and Framingham Risk Score in healthy men and women: a randomised, controlled, double-masked trial: the Flaviola Health Study”
Authors: R. Sansone, A. Rodriguez-Mateos, J. Heuel, D. Falk, D. Schuler, R. Wagstaff, G. G. C. Kuhnle, J. P. E. Spencer, H. Schroeter, M. W. Merx, M. Kelm and C. Heiss