Dark
Chocolate Aids In Cardiovascular Health
Almonds, Blueberries,
and Oat Bran Help, Too
Dark Chocolate provides
improved cardiovascular function and lowered risk for heart
disease, according to a report in the Journal of the
American College of Nutrition.
Dr. Mary Engler, a
professor of physiological nursing at the University of California,
San Francisco School of Nursing, says that eating dark chocolate
can make arteries expand, increasing blood flow, and thus reducing
cardiovascular risk.
Milk chocolate does
not provide the same protection, Dr. Engler stresses, because
it is, well, too milky. Look for darker chocolates, because
darkness is an indicator of high levels of flavonoids, the chemicals
that loosen up the arteries.
Flavonoids are naturally-occurring
compounds found in plant-based foods. According to the Chocolate
Information Center, supported by Mars, Inc., scientists
have discovered that one of the functions flavonoids may have
is to act as antioxidants in humans.
Antioxidants are believed
to help the body's cells resist damage by free radicals, which
are formed by numerous processes including when the body's cells
utilize oxygen for energy.
Tastes
Good, Supports Health
You can tell that
a chocolate has a high flavonoid content because "the flavor
is so intense and rich," Dr. Engler says.
Dr. Engler and her
colleagues asked 11 willing participants to eat 1.6 ounces
of flavonoid-rich chocolate every day for two weeks. Another
10 volunteers consumed an equal amount of low-flavonoid chocolate.
Ultrasound measurements
showed that expansion of the arteries in response to greater
blood flow increased by 10 percent in the flavonoid consumers,
while there was a slight decrease in those who got the flavonoid-poor
chocolate.
Blood levels of a
powerful flavonoid, epicatechin, rose more than eightfold for
the high-flavonoid group and remained unchanged for the others.
The study was conducted in
collaboration with the Jean Mayer USDA Human Nutrition Research
Center on Aging at Tufts University.
Flavonoids
Found in a Variety of Foods
Dr. Jeffrey Blumberg,
chief of the center's Antioxidant Research Laboratory, said
the work has expanded to look at other flavonoid-containing
foods.
"Not only chocolate,
but also tea, oat bran, almond skins, and blueberries, all are
good sources of flavonoids," Dr. Blumberg said. "We're trying
to get a better understanding of vital chemicals, flavonoids
being one of the larger groups."
Dark chocolate "happens
to be a rich source of flavonoids," Dr. Blumberg said, but he
adds that "we are not trying to position chocolate as a health
food."
In addition to flavonoids,
chocolate also has a lot of calories and a lot of saturated
fat, neither of which is good for the arteries, he says.
"But in the context
of a reasonable diet, chocolate is not only a pleasurable food
but might contain some health-promoting ingredients," Dr. Blumberg
says.
Recommendations about
dark chocolate can be compared with those about wine, Dr. Engler
says.
An occasional glass
or two of wine has been shown to be associated with a reduced
risk of cardiovascular disease, she says, "but people should
not be overindulgent with wine. The same is true of dark chocolate
in moderation as part of a well-balanced diet."
Always consult your
physician for more information.
Online
Resources
(Our Organization
is not responsible for the content of Internet sites.)
Centers
for Disease Control and Prevention (CDC)
Chocolate
Information Center, Mars Inc.
HealthierUS.Gov
National
Institutes of Health (NIH)
National
Library of Medicine
National
Women's Health Information Center
Office
of Research on Women's Health
US
Food and Drug Administration |
July
2004
Dark
Chocolate Aids In Cardiovascular Health
Tastes
Good, Supports Health
Flavonoids
Found in a Variety of Foods
What
Are Flavonoids?
Plants
Benefit From the Cocoa, Too
Online
Resources
What
Are Flavonoids?
According to the American
Heart Association (AHA), flavonoids are compounds with
varied chemical structures present in fruits, vegetables, nuts
and seeds.
The major flavonoid
categories are flavonols, flavones, catechins, flavanones, and
anthocyanins.
The main dietary sources
of these compounds are tea, onions, soy, and wine. The main
flavonoid in onions is quercetin glucoside and the main flavonoid
in tea is quercetin rutinoside.
The AHA
states that flavonoid intake has been inversely linked with
coronary heart disease in the Zutphen Elderly Study, the Seven
Countries Study, and a study in Finland.
That is, people with
a low intake of flavonoid had a higher death rate from coronary
heart disease than did those who consumed more flavonoid (about
five to six cups of tea per day).
The AHA
states that some flavonoids have toxic effects (gastrointestinal
or allergic), especially if taken in large amounts.
More study is needed
on the major classes of flavonoids to understand their
structure, effectiveness, and potential harmful effects, the
AHA states.
The link between flavonoids
and atherosclerosis is based partly on the evidence that some
flavonoids have antioxidant properties. For example, the phenolic
substances in red wine inhibit oxidation of human LDL.
Flavonoids also have
been shown to inhibit the aggregation and adhesion of platelets
in blood, which may be another way they lower the risk of heart
disease.
Isoflavones in soy
foods have been reported to lower plasma cholesterol and also
to have effects similar to estrogen.
Always consult your
physician for more information.
Plants
Benefit From the Cocoa, Too
Flavonols play an
important protective role in the cacao plant, according to the
Chocolate Information Center.
The Center
states that compounds created naturally to protect the
health of the plant may also help to maintain the health of
humans as well.
Research suggests
that flavonols work two ways to protect plants - they contribute
to the healing of wounds and use antimicrobial properties
for protection against disease.
Flavonols can either
be present in the plant at the time of the injury or can be
produced in response to the injury.
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