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Study Crushes Garlic's Claim to Lower Cholesterol
Neither the
fresh or pill-packaged varieties brought LDL levels down
By Alan Mozes
MONDAY, Feb.
26 (HealthDay News) -- For those enduring bad breath for
the sake of good cardiovascular health, a new study
brings bad news: Garlic does not lower LDL, the
so-called "bad cholesterol."
The finding,
reported in the Feb. 26 issue of the Archives of
Internal Medicine, applies to both fresh garlic and
popular garlic supplements.
"We did a
bigger and better trial than has ever been done before
and with NIH (National Institutes of Health) funding,
not with supplement-manufacturer funding. And as far as
lowering cholesterol, garlic didn't work," said
Christopher D. Gardner, study lead author and nutrition
scientist and assistant professor with the Stanford
Prevention Research Center in Stanford, Calif.
Too much
low-density lipoprotein (LDL) cholesterol in arteries is
known to elevate risks for stroke or heart attack.
Typically, patients with LDL levels below 130 mg/dl are
considered to be in the healthy range.
The notion
that garlic is one of nature's answers to all sorts of
serious ills stretches as far back as Egypt, circa 1500
B.C., experts say.
More recent
interest in garlic's specific potential as an LDL-lowering
agent stems from lab work and animal testing done over
the past few years. That data suggested that crushing
garlic produces a sulfur-containing compound, allicin,
that might block cholesterol synthesis.
To test that
theory, Gardner's team analyzed the impact of garlic and
garlic supplements on LDL blood levels in 192 men and
women between the ages of 30 and 65. All of the study
participants had moderately high LDL cholesterol
readings that averaged out at about 140 mg/dl.
The
researchers focused on this moderate-level group,
because they assumed that those with more severely
elevated LDL would be taking prescription drugs, such as
statins, that could confound the results. By contrast,
patients with moderate elevations were more likely to
combat the problem with supplements alone.
Pregnant
women, smokers, those with heart disease, cancer, or
diabetes, and current users of high blood pressure or
lipid-lowering medications were excluded from the study.
Six days a
week for six months, all the participants ingested the
equivalent of a four-gram clove of garlic in one of
three forms: either mixed into a sandwich in raw form or
as one of two popular commercially-available
supplements, Garlicin and Kyolic-100.
The authors
pointed out that the two chosen supplements are
manufactured differently, with Garlicin being a powdered
option that is the only brand so far to have
demonstrated an ability in lab studies to produce a
consumable amount of allicin equivalent to raw crushed
garlic.
By contrast,
Kyolic is an aged-garlic extract specifically designed
to reduce bad breath side-effects in users. This option
was described by the authors as "one of the most popular
brands on the market" and is the only supplement to have
been previously tested for cholesterol-lowering
abilities in more than one clinical trial.
Gardner and
his team noted that in order to match the properties
found in four grams of fresh garlic, patients in the two
supplement groups actually consumed slightly more than
the daily-recommended dosage printed on either
supplement's label.
The results:
Blood tests revealed that none of the garlic options had
any "clinically relevant effect" on LDL concentrations
over the course of the study, either in the short run or
the long run.
They concluded
that neither dietary garlic nor supplements are likely
to offer any such benefit to most patients seeking to
lower their LDL levels.
Nevertheless,
future research might identify certain sub-groups of
people who might still derive LDL-lowering benefit from
garlic (such as those with more severe LDL elevations)
or that higher daily doses of garlic consumption might
prove at least somewhat effective.
"We are
actually very disappointed with the results we do have,"
admitted Gardner. "We really thought garlic was going to
work. Now, maybe you could say the supplements didn't
work because they're not the same as fresh garlic. But
then, fresh garlic should've worked, if anything was
going to work. And it didn't."
"So, I'd say
you really ought to just enjoy your hummus with whole
wheat bread and your Asian vegetable stir-fry with
garlic, which, of course, makes it so much more
enjoyable," joked Gardner. "But if you're going to take
a garlic supplement, it should be for something other
than cholesterol lowering, because in real life it
doesn't work."
Ruth Kava,
director of nutrition at the American Council on Science
and Health in New York City, expressed little surprise
at the study findings.
"I think that
what's happened over the last 10 to 12 years in this
country is that supplements have gotten a much better
rep than many deserve," she said. "The garlic claim has
been out there for quite a while, but manufacturers have
been making all sorts of qualified claims that aren't
really backed up with substantial clinical evidence."
While Kava
called for more research to confirm the latest finding,
she encouraged patients looking to lower their
cholesterol in other ways to take advantage of proven
methods.
"The tried and
true things that are going to lower LDL cholesterol are
statins, which, although they can't be taken by
everyone, are really very effective; and lifestyle
changes such eating a diet with less saturated fat,
getting exercise, and losing weight," she advised.
"Unfortunately, there is no magic pill."
(The above
article has been taken from MSN Health & Fitness) |