A new study published in the July 4 2007 issue of the Journal of the American Medical Association found that to have a small blood pressure lowering effect, you may only need a tiny piece of dark chocolate daily for a couple of weeks, if you are healthy.
The study led by Dirk Taubert, M.D., Ph.D., of University Hospital of Cologne, Germany, and colleagues, who have studied cocoa rich food for quite some years, found eating no more than 30 calories a day of dark chocolate was associated with a lowering of blood pressure in healthy subjects who had high blood pressure but in normal ranges.
But overindulging in dark chocolate might have a drastic effect on your calorie calculations, and packing on pounds could raise blood pressure. So portion control is necessary to help you have your dark chocolate and reap its health benefits.
Forty-four people with raised blood pressure were put into two groups. One ate six grams of dark chocolate daily, the other the same amount of white chocolate.
"The dark chocolate reduced the systolic blood pressure, the top reading of the blood pressure, by 2.9 units, and the diastolic blood pressure, the bottom reading of blood pressure by 1.9 units. The white chocolate had no effect on blood pressure,"
"Although the magnitude of the blood pressure reduction was small, the effects are clinically noteworthy," Taubert's team writes.
On a population basis, it has been estimated that a 3-mm Hg reduction in systolic BP would reduce the relative risk of stroke mortality by 8 percent, of coronary artery disease mortality by 5 percent, and of all-cause mortality by 4 percent," the authors wrote.
The reduction of mortality by consuming flavanols-loaded dark chocolate is not just speculation of the German researchers. Through at least partially the blood lowering mechanism, the mortality from coronary heart disease and stroke may be reduced by as much as 19 percent in those who ate the highest amounts of cocoa rich foods, compared to those who ate the lowest amounts, according to Ding E L. and colleagues from Department of Epidemiology at Harvard University School of Public Health.
Previous studies have shown high consumption of cocoa-rich foods such as dark chocolate can lower blood pressure and researchers believe that is due probably to the action of the cocoa polyphenols such as flavanols. Polyphenols in dark chocolate seem to increase the production of a substance in the body called nitric oxide, which causes the blood vessels to widen, making more room for the blood to flow and lowering blood pressure.
Milk chocolate, white chocolate, or dark chocolate eaten with milk do not have the same benefits as plain dark chocolate.
Our study," says the doctor, "provides sufficient evidence to recommend low amounts of polyphenol-rich dark chocolate as an addition to a healthy diet."
The researchers stressed that asking people to eat a couple of chunks of chocolate a day was far easier than encouraging "complex behavioral changes" to help them reduce their blood pressure.
"But over indulgence in chocolate is not good as it is high in fat and calories. Fruits and vegetables provide a range of polyphenols, as well as important vitamins and minerals. Eating five or more portions of fruit and vegetables a day is therefore the best way to protect your heart - and you don't need to worry about over-indulging," suggested Sara Stanner, nutritionist, The British Heart Foundation.