July 19, 2005
Good news for dark chocolate-lovers
WASHINGTON (Reuters) - Dark chocolate can not only soothe
your soul but can lower blood pressure too, researchers
The study, published by the American Heart Association,
joins a growing body of research that show compounds found in
chocolate called flavonoids can help the blood vessels work
more smoothly, perhaps reducing the risk of heart disease.
"Previous studies suggest flavonoid-rich foods, including
fruits, vegetables, tea, red wine and chocolate, might offer
cardiovascular benefits, but this is one of the first clinical
trials to look specifically at dark chocolate's effect on
lowering blood pressure among people with hypertension," said
Jeffrey Blumberg of Tufts University in Boston, who led the
"This study is not about eating more chocolate," Blumberg
added. "It suggests that cocoa flavonoids appear to have
benefits on vascular function and glucose sensitivity."
Scientists are far from being able to make specific
recommendations for patients based on their research on
chocolate, and nutritionists have urged people to be cautious
because chocolate is high in fat, sugar and calories.
Blumberg and colleagues at the University of L'Aquila in
Italy studied 10 men and 10 women with high blood pressure.
For 15 days, half ate a daily 3.5 ounce (100 gram) bar of
specially formulated, flavonoid-rich dark chocolate, while the
other half ate the same amount of white chocolate.
Then each group "crossed over" and ate the other chocolate.
"White chocolate, which has no flavonoids, was the perfect
control food because it contains all the other ingredients and
calories found in dark chocolate," Blumberg said.
"It's important to note that the dark chocolate we used had
a high level of flavonoids, giving it a slightly bittersweet
taste. Most Americans eat milk chocolate, which has a low
amount of these compounds."
Writing in the journal Hypertension, Blumberg's team said
when the volunteers ate the special dark chocolate, they had a
12 mm Hg decrease in systolic blood pressure (the top number in
a blood pressure reading) and a 9 mm Hg decrease in diastolic
blood pressure (the bottom number) on average.
Blood pressure did not change when the volunteers ate white
"This is not only a statistically significant effect, but
it's also a clinically meaningful decline," Blumberg said.
"This is the kind of reduction in blood pressure often found
with other healthful dietary interventions."
Eating dark chocolate also seemed to improve how the body
used insulin, and reduced low density lipoprotein (LDL) or
"bad" cholesterol by about 10 percent on average.
"The findings do not suggest that people with high blood
pressure should eat lots of dark chocolate in lieu of other
important blood pressure-reduction methods, such as medication
and exercise," Blumberg said. "Rather, we are identifying
specific flavonoids that can have a benefit on blood pressure
and insulin sensitivity."