Public release date: 11-May-2004 [ Print This Article |
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Contact: Michael Bernstein [email hidden] 202-872-6042
American Chemical Society
Orange, tangerine peels could be better than drugs for
lowering cholesterol A compound found in the peels of citrus
fruit has the potential to lower cholesterol more
effectively than some prescription drugs, and without side
effects, according to a study by U.S. and Canadian
researchers.
A joint study by the U.S. Department of Agriculture and KGK
Synergize, a Canadian nutraceutical company, identified a
class of compounds isolated from orange and tangerine peels
that shows promise in animal studies as a potent, natural
alternative for lowering LDL cholesterol (bad cholesterol),
without the possible side effects, such as liver disease and
muscle weakness, of conventional cholesterol-lowering drugs.
The findings will be described in the May 12 print issue of
the Journal of Agricultural and Food Chemistry, a peer-
reviewed publication of the American Chemical Society, the
world's largest scientific society.
The compounds, called polymethoxylated flavones (PMFs), are
similar to other plant pigments found in citrus fruits that
have been increasingly linked to health benefits, including
protection against cancer, heart disease and inflammation.
The study is believed to be the first to show that PMFs can
lower cholesterol, the researchers say.
"Our study has shown that PMFs have the most potent cholesterol-
lowering effect of any other citrus flavonoid," says
Elzbieta Kurowska, Ph.D., lead investigator of the study and
vice president of research at KGK Synergize in Ontario,
Canada. "We believe that PMFs have the potential to rival
and even beat the cholesterol-lowering effect of some
prescription drugs, without the risk of side effects."
PMFs are found in a variety of citrus fruits. The most
common citrus PMFs, tangeretin and nobiletin, are found in
the peels of tangerines and oranges. They are also found in
smaller amounts in the juices of these fruits.
Using hamster models with diet-induced high cholesterol,
the researchers showed that feeding them food containing
1 percent PMFs lowered levels of LDL cholesterol by 32 to
40 percent.
Previous animal studies by others have shown that similar
flavonoids, particularly hesperidin from oranges and
naringin from grapefruit, also may have the ability to lower
cholesterol, although not as effectively as PMFs, according
to Kurowska.
Treatment with PMFs did not appear to have any effect on
levels of HDL cholesterol, or good cholesterol, the
researcher says. No negative side effects were seen in the
animals that were fed the compounds, she adds.
The researchers are currently exploring the compound's
mechanism of action on cholesterol metabolism. They now
suspect, based on early results in cell and animal studies,
that it works by inhibiting the synthesis of cholesterol and
triglycerides inside the liver.
A long-term human study of the effect of PMFs on high LDL
cholesterol is now in progress. While drinking citrus fruits
is full of health benefits, taking PMF supplements could be
an easier way to lower cholesterol, since a person would
have to drink 20 or more cups a day of orange or tangerine
juice to have a therapeutic effect, Kurowska estimates.
KGK Synergize already has developed a nutrition supplement
containing PMFs combined with a form of vitamin E that
seems to enhance the compound's effect, according to
Kurowska. Marketed as a cholesterol-lowering agent under
the trade name SytrinolTM, the supplement recently became
available in the U.S.
USDA's Citrus and Subtropical Products Laboratory in Winter
Haven, Fla., and KGK Synergize Inc. provided funding for
this study.
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