Green tea may trim 'bad' cholesterol by Reuters
Posted: Thursday, 17 November 2011 7:41AM
Green tea may trim 'bad' cholesterol: study
(Reuters) - Green tea, taken in a capsule or drunk in a cup, may
shave a few points off "bad" cholesterol readings, according to a
U.S. study involving more than a thousand people.
The findings, published in the Journal of the American Dietetic
Association, showed that green tea trimmed 5 to 6 points more from
people's total cholesterol and "bad" LDL cholesterol levels than
dummy capsules or other treatments.
The trials tested either green tea itself or capsules containing
green-tea compounds called catechins, which are thought to decrease
cholesterol absorption in the gut.
Green tea in a cup was more consistently effective than capsules,
though the benefits overall were fairly small, noted senior
researcher Olivia Phung, an assistant professor of pharmacy at
Western University of Health Sciences in Pomona, California.
"If someone is already taking medication for their cholesterol,
they should stick with it and not try to trade it for green tea,
either capsules or the beverage," she told Reuters Health in an
email.
But adding green tea to your diet could be one way to further
improve cholesterol numbers, she said.
The researchers, however, found no strong evidence that green tea
boosted "good" HDL cholesterol, or cut triglycerides, another type
of blood fat.
Phung's team pooled the results of 20 clinical trials that involved
a total of 1,415 adults.
Participants were randomly assigned to either use green tea every
day, as a beverage or capsule, or be part of "control" groups that
took placebo capsules, drank a low-catechin tea or downed
water.
The trials lasted anywhere from three weeks to six months and the
benefits seemed to be limited to people who already had high
cholesterol when they entered the study.
Overall, tea seemed more effective than capsules, though Phung said
there isn't enough data to be sure that the beverage is better than
the extract.
A number of clinical trials that examined whether green tea, or its
extracts, can benefit people's cholesterol levels have reached
mixed conclusions. Most of the trials have been small, making them
less reliable.
There are other questions too, including what dose of green tea
catechins is ideal.
In the trials Phung's team studied, the researchers were unable to
test for a "dose-response" effect, which would have shown whether
the cholesterol benefits increase as the catechin dose goes
up.
"We would really need to have some head-to-head studies comparing
the different forms of green tea in order to show which ones work
more effectively," Phung said.
As for side effects, green tea is considered safe in moderate
amounts, though the drink and the extracts contain caffeine, which
some people may need to avoid.
There have also been a few dozen cases of liver damage reported
among people using green tea extracts, but it's not certain that
the supplements are to blame.
Story & Photos Copyright 2011 Reuters
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