STATE COLLEGE, Pa., Oct. 23 (UPI) -- Cocoa powder and dark chocolate may help delay the progression of cardiovascular disease, Pennsylvania State University researchers report in Tuesday's American Journal of Clinical Nutrition.
Chocolate contains a healthful nutrient known as a flavonoid that appears to have a modest protective benefit for blood vessels. In previous research, flavonoids in other plant-based foods such as green tea, red wine, soybeans and apples, have been found to produce health benefits as well. Chocolate lovers now can add their favorite food to that list.
The current study shows cocoa and dark chocolate can slow the oxidation of low-density lipoprotein or LDL -- also known as the bad cholesterol. And that helps prevent the build-up of the plaques that can block blood vessels.
"Cocoa and chocolate are 'fun foods' and I think these results show they can contribute to a healthy diet," said Penny Kris-Etherton, professor of nutrition at Penn State and leader of the study. She said this is especially true if the cocoa and chocolate are eaten in forms that do not include large amounts of fat and sugar, such as in a hot chocolate drink.
The experiment tested 10 men and 13 women, ages 21 to 62. One group was given an experimental diet containing about 22 grams of cocoa powder and 16 grams of dark chocolate daily for four weeks. The other group was given a diet low in flavonoids for four weeks. Afterward the two groups ate their regular diet for two weeks and then went back to the experimental diet for another four weeks.
Both experimental diets contained the same amounts of caffeine and theobromine, stimulants found in cocoa and chocolate.
Study participants had their blood drawn at the end of each diet period. The LDL was extracted and then subjected to oxidation in the laboratory.
Etherton and her colleagues found it took more time for oxidation to start in the group given the chocolate and cocoa, which she interpreted as a positive result in terms of hampering LDL cholesterol damage.
The results showed oxidation among the chocolate diet group was about 8 percent slower than the other group. In addition, the blood plasma of the participants showed 4 percent higher high-density lipoprotein or HDL -- the good cholesterol -- in the chocolate-eating group.
"The incorporation of dark chocolate and cocoa powder into the diet is one means of effectively increasing antioxidant intake," Etherton said. However, she does not recommend eating unlimited amounts of chocolate, but rather balancing the diet with other antioxidant-rich foods, such as fruits, vegetables, tea and wine.
"We're not trying to figure out the ultimate diet," said Dee Maddox, clinical coordinator of the study at Penn State. "All we're saying is that there are no bad foods. It's all about moderation and serving size."
In an editorial in the same issue, Paul Nestel, head of cardiovascular nutrition at the Baker Medical Research Institute in Melbourne, Australia, cautioned that while the results showed the benefits of cocoa flavonoids, that does not necessarily mean everyone should binge on chocolate.
He points to earlier studies that generated what he referred to as "oversimplified" responses to scientific data, including people going on a Japanese diet including green tea and soy and a Mediterranean diet based on olive oil.
Nestel said it is better to look at these studies as pieces of evidence that help scientists better understand the benefits of a diversified food supply.
The Penn State study was funded by the American Cocoa Research Institute.
(Written by Lori Valigra in Cambridge, Mass.)