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Anti-Aging
Supplement May Clog Arteries
Adding another chapter to the conflicting
history of medical reports about the supposed "anti-aging" supplement
DHEA, a new study suggests the hormone could contribute to clogged
arteries.
Researchers examined the effects
of DHEA only in laboratory tests, not in humans. Even so, the
study's authors are recommending against use of the supplement
outside of research.
"People should refrain from taking
DHEA in an unsupervised fashion," says co-author Dr. Martin K.C.
Ng, a cardiologist at Royal Prince Alfred Hospital in Sydney,
Australia.
DHEA, which the body produces naturally,
has become one of the most popular and controversial dietary supplements
on the market. Among other things, proponents say DHEA can boost
the immune system, improve memory, help people lose weight and
combat low sex drives. The last benefit may be the biggest grabber.
"Aging gentlemen often take DHEA
to supplement their diet, hoping that will boost their testosterone,"
says Dr. Michael V. Sofroniew, a professor of neurobiology at
the University of California at Los Angeles.
Indeed, DHEA is directly linked
to testosterone and other hormones. DHEA was originally thought
to serve mainly as a kind of parent to the other hormones, but
now researchers think it serves purposes of its own, Sofroniew
says.
For the most part, however, DHEA
remains "pretty mysterious," Sofroniew says. Body levels of DHEA
peak during adolescence and then drop off, with especially low
levels reported among depressed people. But it's not clear if
those levels are a cause or effect of depression, Sofroniew adds.
Some researchers have suggested
DHEA may prevent heart disease, but no one has examined that theory
by launching a sophisticated test among humans, Ng notes. "In
fact, very little is known about the potential effects of DHEA
on heart disease," he says. "Despite this lack of evidence for
safety or benefit, many people are taking DHEA in the U.S. on
an unsupervised, over-the-counter basis."
Ng and his colleagues exposed human
cells to DHEA and watched the results. They report their findings
in the Dec. 3 issue of the Journal of the American College
of Cardiology.
The study found DHEA may actually
promote heart disease. When under the influence of DHEA, some
cells appear to take in more cholesterol, potentially clogging
arteries.
However, "a limitation of our study
is that we studied the direct administration of DHEA to human
cells on a plastic dish rather than to a human being," Ng admits.
In humans, the interaction of hormones is more complicated, he
explains.
At this early point in research,
it's not clear if the potential risks to the heart posed by DHEA
may be as dire as those posed by smoking, diabetes and obesity,
Ng says. But he still advises plenty of caution about its use.
Peter J. Hornsby, a professor of
physiology at the University of Texas Health Science Center, agrees
that DHEA's effects on the heart remain unclear, especially considering
that young people naturally have high levels of the hormone but
don't seem to suffer from ill effects.
For the time being, it's "very
dangerous" for people to take DHEA on their own, Hornsby says.
"We don't know what the normal function of this hormone is in
young adults, and we have no idea why we have this hormone" in
the first place.
More information
To learn more about DHEA, try quackwatch.org
for a skeptical view. The Council for Responsible Nutrition, a
supplement trade group, says it can't
recommend whether its members should sell DHEA. Also, the
Mayo
Clinic has a page on anti-aging therapies.
Reference
Source 101
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