A reasonable amount of chocolate lowers blood pressure and prevents the risk of heart attacks. German nutritionists obtained this result from an eight-year survey of 19,357 people aged 35 to 65 years. The risk of a heart attack among those eating chocolate was a third lower than among those not fond of chocolate. The positive effect is ascribed to the cocoa substance flavanol.
“Flavanol improves the availability of carbon monoxide in the inner walls of blood vessels,” explains Brian Buijsse of the German Institute of Human Nutrition in Potsdam-Rehbrücke. This gas causes relaxation and a dilatation of the muscle cells in blood vessels, lowering blood pressure. However, chocolate will only prevent heart disease if it is eaten as a substitute for other, energy-rich snacks and if body weight stays constant.
The participants in the survey gave information on their diet, lifestyle and health condition and on how much chocolate they ate. During the survey, 166 heart attacks and 136 strokes were recorded. Those who ate 7.5 grams of chocolate a day — particularly dark chocolate — had a lower blood pressure, and their risk of a heart attack was 39 percent lower than that of those with a daily ration of 1.7 grams.
Source: Bild der Wissenschaft online, 31 March 2010, www.wissenschaft.de/wissenschaft