The discovery of flavonoids
and the bevy of heart-healthy benefits they possess has been a boon to wine and
chocolate lovers.
The antioxidant-rich compounds found in the seeds and skins of plants, such
as grapes, cocoa beans, and citrus fruits, first gained the attention of researchers
in the early 1990s as a means of explaining the so-called French Paradox. Researchers
proposed then that French people had lower rates of heart attacks because they
drank moderate amounts of red wine with their meals.
Since then, more than 300 studies on grape flavonoids have shown that drinking
red wine or grape juice may help blunt the artery-clogging effects of a fatty
meal and reduce the risk of heart disease over the long-run.
Many of the same flavonoids in grape products are also found in varying concentrations
in green and black tea as well as chocolate, but the bulk of research so far
has been focused on grape flavonoids.
"It is exciting that different investigators dealing with grape products,
whether it be red wine, de-alcoholized red wine, grape juice, or grape seed and
skin extracts, they are all seeing some significant, potentially beneficial things," says
John D. Folts, PhD, professor of medicine and nutritional science at the University
of Wisconsin Medical School.
Folts says animals with high cholesterol will develop atherosclerosis or hardening
of the arteries in about six to nine months, a process in humans that takes 20
to 30 years. But several recent studies have shown that when these animals are
given grape products, the artery-clogging process slows down.
"The suggestion is that the same thing would work in humans," says Folts.
He says the early studies on tea and chocolate flavonoids are promising, but
it's still too early to draw any definitive conclusions from them.
Researchers say flavonoids may help promote heart health in several ways,
such as:
- Helping to prevent blood clots, which may trigger a heart attack or stroke.
- Preventing cholesterol from entering and damaging blood vessel walls.
- Improving the health of arteries, making them expand and contract more readily,
helping them carry blood more effectively.
- Stimulating the production of nitric oxide, which may stall hardening of
the arteries.
Alice H. Lichtenstein, DSc, professor of nutritional science and policy at
Tufts University, says although the research is reasonably good in showing that
drinking a moderate amount of wine, defined as one or two glasses per day for
men and no more than one glass per day for women, is associated with a lower
risk of heart disease, it is also associated with an increased risk of breast
cancer.
"There is still some confusion over alcohol, and I think that's understandable
because it has potentially good and bad effects," says Lichtenstein. "One should
not start drinking if they don't already, and they have to really weigh the risks
and benefits."
She says it's difficult to make a broad recommendation for drinking wine or
other types of alcohol based on its potential health benefits because there are
also some people who may be more likely to have substance abuse problems with
alcohol.
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