Cocoa Boosts Heart Health
Flavonoid-Rich Dark Chocolate Improves Blood Vessel Function
By
Charlene Laino
WebMD Health News
Reviewed By
Louise Chang, MD
March 24, 2007 (New Orleans) -- There is more sweet news about chocolate. A
cup of cocoa a day may help drive heart disease away, researchers say.
Overweight adults who drank a specially processed cocoa beverage
significantly improved their blood vessel function in just two hours.
Improved blood function, in turn, mitigates the risk of cardiovascular
disease, says researcher Valentine Yanchou Njike, MD, of the Yale Prevention
Research Center in New Haven, Conn.
Njike credits flavonoids, a group of antioxidant compounds also found in
fruits and vegetables. The more flavonoid-rich foods you eat, the lower your
risk of heart disease, he says.
Studies have shown flavonoids appear to benefit blood vessel function by
influencing the body's production of nitric oxide, which helps regulate blood
vessel tone.
Concentrated Flavonoid Source
Cocoa and other dark chocolate products are considered one of the most
concentrated sources of flavonoids, Njike says.
But go easy on the milk chocolate: Though it too contains flavonoids, fats
in milk can raise the risk of heart problems, particularly in overweight
people. And white chocolate contains none of the heart-healthy flavonoids, says
Robert S. Rosensen, MD, director of the preventive cardiology center at
Northwestern University Feinberg School of Medicine in Chicago.
"One of the refreshing things about this is that we so often have to tell
patients what they can't do, what they can't eat," says Rosensen, who moderated
a news conference to discuss the findings at the annual meeting of the American
College of Cardiology.
"Here we can tell them that a favorite mood-improving product can also
improve their [heart] health," Rosensen says.
Cocoa Improves Blood Flow
The study involved 45 overweight or obese people aged 30 to 75. "We
chose overweight people because they're at higher risk for cardiovascular
disease," Njike says.
The participants drank an 8-ounce cup of sugar-free cocoa, sugared cocoa, or
a hot nonfat milk beverage each morning for six weeks
The cocoa beverage was made with Hershey's Cacao Reserve, which uses a
process that helps retain the flavonoids naturally found in cocoa beans.
Hershey provided the cocoa beverage and also provided partial funding for the
study.
Results showed that the ability of arteries to relax and expand to
accommodate increased blood flow to the heart increased by about 39% by two
hours after people drank the sugar-free cocoa. When they drank cocoa with sugar
it improved by about 23%. In contrast, it dropped 12% when they consumed the
nonfat milk drink.
Not All Cocoa Processed the Same
Rosensen notes that previous studies have shown that improvement in blood
flow tends to fade about six hours after eating flavonoid-rich foods. "It could
be that we're best off eating small cocoa snacks throughout the day," he
says.
Despite the findings, the researchers caution against bingeing on dark
bonbons. That's because not all chocolate and cocoa products are processed the
same. In some cases, commercial producers of cocoa remove flavonoids because of
their bitter taste, Rosensen note.
"Moderation is key," he tells WebMD.
SOURCES: American College of Cardiology 56th Annual Scientific Session, New
Orleans, March 24-27, 2007. Valentine Yanchou Njike, MD, Yale Prevention Research Center, New Haven,
Conn. Robert S. Rosensen, MD, director, the preventive cardiology center,
Northwestern University Feinberg School of Medicine, Chicago.
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