Cocoa's flavanol richness may slightly drop blood pressure

There's more evidence that flavanol-rich chocolate or other cocoa products may contribute to better health, with the latest research from Australia suggesting that the confection slightly reduced blood pressure inpeople with hypertension as well as those with normal blood pressure.

The Australian researchers analyzed 20 studies over the past decade involving 856 mainly healthy adults, and found "a statistically significant blood pressure reducing effect of flavanol-rich cocoa products compared with control in short-term trials oftwo to 18 weeks duration."

"Although we dont yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease," said Karin Ried, lead researcher of the study from the National Institute of Integrative Medicine in Melbourne.

High blood pressure(a normal levelisbetween 120/80 mm Hg and 129/84 mm Hg)is a prime risk factor for cardiovascular disease, attributing to about half of cardiovascular events worldwide and 37 per centof cardiovascular-related deaths in the Western world. Canada's Heart and Stroke Foundation says high blood pressure is also the No. 1 risk factor for stroke.

For the Australiananalysis,published Wednesday inThe Cochrane Library, the researcherssearched online databases to find randomized controlled trials, which areconsidered the gold standard of medical research. Those trialscompared people eating cocoa products with high flavanol concentrations,to people eating low-flavanol cocoa powder orfoods that contained none of the plant compounds.

The researchers found that study subjects who ate flavanol-rich cocoa products daily for a few weeks experienced ablood pressure dropof about two or three points much less than the effects of blood pressure-lowering medication, but on par with the effects of changing one's diet or taking part in regular exercise.

One downfall of the study is the researchers couldn't verify that flavanols weredirectly responsible for lowering blood pressure in the study participants. However,the compounds,also found in foods such as green tea, berries and red wine, are linked to the body's production of nitric oxide which helps relax blood vessels, resulting in the lowering of blood pressure.

"We were unable to identify any randomized, controlled trials that tested the effect of long-term daily ingestion of cocoa products on blood pressure and there were no trials that measured an effect on clinical outcomes related to high blood pressure such as heart attacks or strokes," the researchers report.

'You still have to exercise'

CBC's John Northcott reported that one downside of the study is that the researchers "looked at so many different studies, and each study used a different amount of cocoa, so they're not sure what the ideal amount is.

"They do think though that [having it] every daymay bea factor,and the other caveat in all this is it's still no replacement for exercise.... you can't sit by the pool and pop chocolates all dayyou still have to get exercise."

The Australian researcherssay more trialscomparing the intake of low-flavanol dosages with flavanol-free controls are needed to test whether low dosagesare effective in reducing blood pressure.

In addition, longer-term trials are needed to determine if regular consumption of flavanol-rich cocoa products help people maintain good blood pressure levels and cardiovascular health over the long term, and whether there are any adverse side-effects of ingesting cocoa products on a daily basis.

The Cochrane Library study was supportedby The University of Adelaide inAustralia and theAustralian Government Primary Health Care Research Evaluation Development (PHCRED) Program.