Good News for Chocolate Lovers
Studies find it helps heart and arteries, but caffeine doesn't get same blessing
FRIDAY, May 21, 2004 (HealthDayNews) -- For those who love dark chocolate and cocoa, take this to heart: Your sinful addiction may actually boost your cardiovascular health.
Chocolate helps the heart and arteries and cocoa does the same in older adults, claim two presentations made this week at the American Society of Hypertension's annual meeting in New York City.
However, another story reported at the same meeting does not give a similar blessing to coffee; it suggests decaffeinated java is easier on your heart than the caffeinated kind.
In the chocolate study, Dr. Charalambos Vlachopoulos, a cardiologist at the Hippokration Hospital at Athens Medical School in Greece, and his team gave 17 healthy volunteers either 100 milligrams of dark chocolate one day and placebo the next, or the placebo first and then the chocolate.
"We measured their arterial stiffness by measuring their wave reflection," Vlachopoulos explained. "Wave is the surge of blood ejected by the heart. The more reflected wave comes back, the stiffer the arteries."
It just so happens stiff arteries predict cardiovascular disease risk.
"We found the wave reflection was decreased three hours after eating the chocolate but not the placebo," he said. That means, he explained, that the arteries are more relaxed.
Chocolate has flavonoids, a group of chemical compounds that are antioxidants and heart-protective. It's too soon to promote chocolate as a health food, said Vlachopoulos, but "a little chocolate might be OK." Just be sure it's dark chocolate, he added.
In the cocoa study, Dr. Naomi Fisher, an endocrinologist at Harvard Medical School, and her team gave 27 healthy subjects, aged 18 to 72, cocoa that was specially processed by the study sponsor, Mars Inc., so the beneficial flavonoids weren't destroyed in the manufacturing process, as they typically are, Fisher said.
Fisher said the team hypothesizes that older people would respond better to the flavonoids found in cocoa than younger people. In the study, 13 were over age 50 and 14 were under age 50. After the cocoa was given, they measured blood flow to the finger, as a way to determine artery health. "In older people, the flow nearly doubled," Fisher said.
Before stocking up on cocoa, Fisher warned, be aware that "most commercially available cocoas have been depleted of beneficial flavonoids." However, she suspects candy manufacturers may develop new products that add or preserve the flavonoids.
Unfortunately for coffee lovers, another study showed caffeinated coffee had an unfavorable effect on the functioning of endothelial cells that line blood vessels and control the ability of vessels to dilate and prevent clot formation.
Dr. Konstantinos Aznaouridis, a cardiologist at Hippokration Hospital at Athens Medical School in Greece, and his team gave 17 healthy young volunteers a cup of regular coffee with 80 milligrams of caffeine or a cup of decaffeinated beverage with less than 2 milligrams of caffeine.
They took a measurement of an index called flow-mediated dilation, which estimates the performance of the endothelial function. The higher the flow-mediated dilation value, the better the function.
"After regular coffee, this value decreased up to one hour after drinking the coffee. When endothelial function decreases, it is the beginning of atherosclerosis, or hardening of the arteries," he said.
"We don't know yet the effects of chronic consumption" he said. "A previous study showed those who drink more than four cups a day have a 2.5-fold increase in cardiovascular events," he said. But other studies that followed came up with conflicting findings, he said.
"It's too soon to tell people to quit drinking coffee," he said.
Another expert familiar with all three studies said the research is interesting, but it's premature to suggest consumers change their eating and drinking habits based on these findings.
"I think all three studies contribute to our knowledge," said Daniel Lackland, a professor of epidemiology and medicine at the Medical University of South Carolina in Charleston. "But the results are all very acute, they happened in a very short period of time. It's important for these studies to take place and to show these immediate reactions. But it doesn't answer the question of whether it causes or prevents disease in the long run."
The studies shouldn't give the message that unlimited quantities of chocolate are good for your heart, Lackland added. "Don't think these studies are saying, 'Go get a box of Whitman's Samplers and enjoy yourself,''' he said. The excess weight that can result from too much chocolate can increase heart disease risk, he noted.