Can dark chocolate and cocoa be healthful?
by Mary Calvagna, MS
Chocolate, also known as "the food of the gods," is a guilty pleasure for many of us. We know it has fat; we know it has calories; we also know it tastes so good. But chocolate may do more than tickle our tongues and our tummies. Recent research is suggesting that chocolate may be an antioxidant soldier in the fight against atherosclerosis.
Atherosclerosis—a type of arteriosclerosis—occurs when cholesterol and other substances accumulate in the inner lining of the artery. This results in a hardening of the arteries, which can lead to coronary heart disease (CHD). CHD accounts for one out of every five deaths in the United States.
Preventing LDL oxidation
The oxidation of LDL cholesterol plays a role in the development of atherosclerosis. Because of this, emphasis has been placed on finding ways to increase the resistance of LDL cholesterol to oxidation. A significant body of evidence supports the role that antioxidant vitamins—most notably vitamin E and to a lesser extent, vitamin C—play in preventing LDL oxidation. Flavonoids—compounds found in fruits, vegetables, tea, and red wine—have been shown to inhibit LDL oxidation as well. Certain cocoas and chocolate can be rich sources of flavonoids. A study published in the American Journal of Clinical Nutrition* looked at the flavonoids present in dark chocolate and cocoa powder and the effect they have on LDL oxidation.
A delicious study
The study involved 23 participants, 10 men and 13 women. They were fed one of two diets, either an average American diet (AAD), which consisted of:
- 52% carbohydrates
- 15% protein
- 33% fat
- 329 mg cholesterol
- 17 g fiber
or the AAD supplemented with 22 grams of cocoa powder and 16 grams of dark chocolate.
The participants stayed on their assigned diet for four weeks, had a two-week break, and then went on the other diet for four weeks. At the end of the first and the second diet periods, blood was drawn from each participant and analyzed for:
- How long it took for LDL oxidation to begin
- How fast oxidation proceeded
- How much oxidized fatty acid was produced
Researchers found that oxidation of LDL cholesterol occurred 8% slower in the participants who ate the AAD diet with chocolate and cocoa when compared with those who ate just the AAD diet. In addition, total antioxidant capacity was more than 4% higher in the people who ate the diet with chocolate and cocoa.
Chocolate free-for-all?
Whoa...wait one second before running to the closest chocolatier. As much as we may want it to, the results of this study do not mean that we can consume chocolate with reckless abandon. The study's authors even address this point:
"We would be remiss in endorsing unlimited quantities of chocolate," the study states. What the researchers do endorse is that chocolate can be "incorporated sensibly and prudently in a healthy diet that emphasizes the intakes of fruits, vegetables, whole grains, skim milk, reduced-fat dairy products, and lean meats, fish, and poultry."
* "Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentration in humans," by Y Wan, et al. American Journal of Clinical Nutrition, October 2001, Issue 74, pp. 596-602.
Last reviewed October 2001 by Medical Review Board
