21 December, 2005 20:55 GMT
Just in time for the candy-clogged holidays, a new Swiss study finds a little dark chocolate each day could slow hardening of the arteries in smokers.
Chocolate is still no substitute for quitting smoking, of course, and the researchers add that the findings are not an excuse to binge on fattening sweets.
However, the results do “provide new important information about the potential beneficial effects of cocoa,” said study author Dr. Roberto Corti, from the University Hospital in Zurich.
Smoother Blood Flow
His team assigned 20 male smokers to either eat about 1.5 ounces of white chocolate or dark, then evaluated the effects of each on blood flow and other parameters.
Before the men ate the chocolate, they were instructed to abstain for a full day from other foods that are rich in the same antioxidants found in cocoa. Those foods include apples, other cocoa products and onions.
The researchers then subjected the smokers to ultrasound scans and blood tests.
Two hours after the men finished eating the dark chocolate, the scans showed improved smoothness of the blood flow through the arteries — an effect that lasted eight hours, according to the report published in the January issue of Heart.
The dark chocolate also halved blood platelet activity, which in turn decreased the risk of blood clots. Antioxidant levels in the blood also rose among those who ate dark chocolate.
White chocolate did not have those effects, however.
A daily sweet chocolate snack is no substitute for stopping smoking, Corti stressed.
Another expert agreed. “In my view, dark chocolate can be included as part of an overall heart-healthy diet — for instance, adequately balancing its calories with a decrease in other desserts and snack foods,” said Jeffrey Blumberg, director of the Antioxidants Research Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, in Boston.
But he said that although dark chocolate contains high levels of flavonoid antioxidants, “it is not a health food, per se, because of its negative attributes — that is, fat and sugar. Further, I feel the only appropriate advice to smokers is to quit smoking.”
Can Help Lower Blood Pressure
Previous research conducted by Blumberg showed dark chocolate can help lower blood pressure. In that study, his team asked 10 men and women to eat 3.5 ounces of dark chocolate every day for 15 days. All of the people in the study had high blood pressure, but weren’t on medication to treat it.
After eating chocolate for 15 days, participants displayed an average drop of 11.6 millimeters of mercy in systolic blood pressure (the top number in the reading), and an 8.5 millimeter-drop in their diastolic pressure (the bottom number).
Another study, published in 2004, found that eating 1.6 ounces of dark chocolate every day for two weeks caused a healthy 10 percent increase in arterial blood flow.
Experts also note that milk chocolate has a much lower level of flavonoid antioxidants than the dark variety.
Dark chocolate, according to Corti, has more antioxidants per gram than other antioxidant-rich foods such as red wine, green tea and berry fruits. But he is talking about only a bit a day, since chocolate is notoriously rich in unhealthy fat.
For instance, according to candy manufacturer Hershey’s, a dark chocolate Mounds bar weighs 1.72 ounces and has 240 calories and 13 grams of fat, most of it saturated fat.
More information: To learn more about calories, visit the Calorie Control Council.