Nov. 5, 2007 (Orlando, Fla.) -- There's more
good news for chocolate lovers. A Japanese study suggests that dark
chocolate can improve blood flow to heart muscle.
That's important because improved coronary blood flow mitigates the risk
of chronic chest pain, or angina, and heart attacks, says Yumi Shiina,
PhD, of Chiba University in Chiba, Japan.
Studies have shown that the sweet treat can also lower your blood
pressure and reduce your risk of diabetes, she says.
Shiina credits flavonoids, a group of antioxidant compounds also found
in red wine, tea, and fruits and vegetables, with dark chocolate's
healthy effects.
Dark Chocolate Rich in Flavonoids
The study involved 39 healthy men who ate a 1.4-ounce candy bar of either
dark chocolate or white chocolate daily for two weeks.
Shiina says the dark chocolate was rich in a potent flavonoid known as cacao
polyphenol, while the white chocolate contained no flavonoids.
The researchers measured what doctors call coronary flow velocity reserve (CFVR).
It's an indicator of the ability of the coronary arteries to dilate and
allow more blood flow to heart muscle tissue.
After two weeks, coronary circulation significantly improved in participants
who ate dark chocolate. There was no change among those who ate white
chocolate.
4 Times as Many Flavonoids
Cacao polyphenol contains four times as many disease-fighting flavonoids per
serving than red wine or tea, Shiina says.
That's not to say you can indulge in dark chocolate with impunity, says
Sidney Smith, MD, a past president of the American Heart Association and
professor of medicine at the University of North Carolina in Chapel Hill.
"You have to balance the fats and calories of the candy bar against the
benefits of flavonoids," he tells WebMD.
Shiina says that in the future, development of a cacao polyphenol supplement
could overcome the problem.
The study was presented here at the American Heart Association's
Scientific Sessions 2007.
