Since chocolate contains many myriad substances the scientist thinks that it might impart important health benefits. Chocolate contains flavanols a chemical compound that is known for its potent antioxidant and anti- inflammatory actions. A statistical correlation between flavanol intake and risk for cardiovascular disease has been found in many large scale human studies.
And animal studies suggest that this relationship may be due to the physiologic effects that flavanols have on chronic inflammation, blood vessel health, and circulating lipid levels.
However, few controlled human intervention studies have been conducted to test the direct effect of chocolate consumption on these variables.
Researchers.at San Diego State University tested their hypothesis that chocolate, in particular dark chocolate which contains higher levels of flavanols than milk chocolate, may protect against the risk of cardiovascular disease by lowering blood pressure, blood flow, and improving blood lipid levels.
The lead researcher Hong and her team assigned 31 men and women to eat about 1.7 ounces (a standard-size chocolate bar is about 1.5 ounces) of dark, white, or ''bloomed" dark chocolate every day for 15 days.
Blood pressure, forearm skin blood flow, circulating lipid profiles, and blood glucose levels were recorded at the beginning and end of the study.
Compared to those who ate white chocolate, those eating either dark chocolate had:
- Lower blood sugar levels
- Improved LDL or ''bad" cholesterol
- Improved HDL or "good" cholesterol
She didn't find differences in blood pressure between the white chocolate eaters and the dark chocolate eaters.
As for why the dark chocolate may help blood sugar levels Hong explain that, Hong says that the antioxidants may help the body use its insulin more efficiently to control blood sugar. This, in turn, helps to lower blood sugar levels naturally.
The white chocolate, but not the dark, made the skin blood flow slow down -- not a desirable quality. Skin blood flow is a way to measure how the blood vessels are functioning- says author. The researchers concluded that dark chocolate may reduce the risk of cardiovascular disease by improving glucose levels and lipid profiles.
Caution from researchers
Although habitual dark chocolate consumption may benefit one's health by reducing the risk of cardiovascular disease—it must be eaten in moderation because it can easily increase daily amounts of saturated fat and calories.
While a little dark chocolate is good, a lot is not better. Chocolate still is loaded with calories. If you're going to eat more chocolate, you'll have to cut back somewhere else. And remember that a balance diet and plenty of exercise is still the key to Heart health.
The author also commented “We had great compliance with our study subjects because everybody wanted to eat chocolate. We actually had to tell them not to eat more than 50 grams a day."
Joe Vinson PhD, a professor of chemistry at the University of Scranton and a long-time researcher on antioxidants in foods says to WebMD, “Some of the findings echo that of other research, The fact that white chocolate (containing fat and sugar) makes the skin blood flow slow down is newsworthy," he says. The message to stay healthy, he says, is: "Don't eat fat and sugar without antioxidants."
The finding about bloomed chocolate is reassuring if you're wondering whether to eat old chocolate, Vinson says. He says it may look bad but that it still has active antioxidants.
Eric Ding, PhD, a nutritional epidemiologist and instructor of medicine at Harvard Medical School comments, “Other studies have found lowering of blood pressure with dark chocolate, The fact that Hong did not, he says, could simply be because of the small size of the study.
"The LDL decrease and the HDL increase are consistent with previous research," Ding tells WebMD- Review published in WebMD,
The group reports that it is planning follow-up studies involving more subjects and a longer duration of chocolate consumption. Results from this study will be presented April 24, 2012 at the Experimental Biology 2012 meeting in San Diego, CA.
Provided by Federation of American Societies for Experimental Biology