| |
 |
 Appeared in CNN.
(AP) -- After a sweaty health club workout, don't kid yourself that the
candy bar in your gym bag is health food. Despite the recent buzz over the
confection's heart-protecting qualities, new research suggests that not
all kinds of chocolate are beneficial.
European researchers say eating milk chocolate, which is most commonly
used in candy bars, does not raise antioxidant levels in the bloodstream.
They found the same discouraging result among patients who drank milk
while eating dark chocolate.
The results suggest that milk and other dairy products somehow discourage
the body's ability to absorb the protective compounds in chocolate. Only
subjects who ate dark chocolate showed a temporary increase in their
antioxidant levels.
Details of the study appear in Thursday's issue of the journal Nature.
"This puts in question the possible protective effects of (chocolate) milk
shakes or ice cream or other dairy products," said co-author Alan Crozier
of the University of Glasgow.
Nor does Crozier endorse the idea that eating dark chocolate is healthier.
It still contains plenty of fat and sugar.
"Don't think by eating five or six bars a day you're doing yourself any
good," he said.
The blood pressure effect
Cocoa beans contain plant chemicals called flavonoids, a kind of
antioxidant polyphenol present in many fruits, vegetables, tea and red
wine. Some studies indicate flavonoids protect the heart from damaging
effects of unstable oxygen compounds called free radicals that, among
other things, can damage blood vessels.
A German study published Wednesday in the Journal of the American Medical
Association suggests that eating dark chocolate can lower blood pressure.
Other experiments show cocoa flavonoids may reduce harmful blood clotting
properties and decrease low-density-lipoprotein (LDL), known as the "bad
cholesterol."
The JAMA study involved adults with untreated mild hypertension who ate
3-ounce chocolate bars daily for two weeks. Half of the patients got white
chocolate, half got dark chocolate.
Blood pressure remained pretty much unchanged in the group that ate white
chocolate, which does not contain polyphenols. But after two weeks,
systolic blood pressure -- the top number -- had dropped an average of
five points in the dark-chocolate group. The lower, or diastolic, reading
fell an average of almost two points.
In 1998, a Harvard study of nearly 8,000 of its male graduates determined
that eating the equivalent of few bars of chocolate a month lowered the
risk of death by 36 percent as compared to abstainers.
No recommended daily allowance
In the latest experiments, which were conducted without industry funding,
Crozier and researchers in Italy first determined the antioxidant levels
of dark chocolate and milk chocolate in the lab. Dark chocolate had twice
as much, Crozier said, in part because milk chocolate contains only about
half as much actual chocolate.
The researchers then gave chocolate bars to seven women and five men who
were between 25 and 35 years old. All of the participants were nonsmokers,
had normal blood lipid levels, took no prescription drugs or vitamins and
were not overweight.
After they ate dark chocolate bars, the antioxidant potential measured in
their blood increased an average of 18 percent and remained elevated for
three hours.
Lead author Mauro Serafini said the subjects' antioxidant potential did
not rise noticeably when they consumed a glass of whole milk with the dark
chocolate, or when they ate milk chocolate. He said it's possible that
antioxidants bind with milk proteins making absorption more difficult.
Scientists who did not contribute to the research said the protective
aspects of flavonoids in chocolate have not been proven.
"I guess this means to be healthy you should eat chocolate with red wine,"
said Andrew L. Waterhouse, a nutrition professor at the University of
California at Davis. "That is, if you believe the antioxidant hypothesis.
"No one has taken flavonoids, given them to people in a controlled
scenario and shown that people who take them are more healthy than those
who don't," he said.
Dr. Robert H. Eckel, a spokesman for the American Heart Association, said
there is not enough information to recommend chocolate as a food that
reduces the risk of heart disease.

August 27, 2003.
|
|