WEDNESDAY, Feb. 8, 2006 (HealthDay News) -- Millions of older American men
use the herbal supplement saw palmetto to treat an enlarged prostate, but
a new study concludes the product doesn't work.

A few smaller studies had suggested the extract might be of limited
benefit to men with enlarged prostate, clinically known as benign
prostatic hyperplasia (BPH).

However, this controlled, blinded study of 225 men found that, "over a
12-month period, saw palmetto was no better than placebo in changing
symptoms for this condition," said lead researcher Dr. Stephen Bent, an
assistant professor of medicine at the University of California, San
Francisco.

His team's research, published in the Feb. 9 issue of the New England
Journal of Medicine, is "the most thorough and well-controlled study of
the effect of saw palmetto on men with BPH that's ever been done," added
Dr. Ronald A. Morton, director of urologic oncology at the Cancer
Institute of New Jersey.

Morton, who co-authored a related editorial on the findings, said,
"Obviously, for anyone who holds saw palmetto in high regard, these
results are a little bit disappointing."

Still, both experts agreed there's no evidence that the herb -- an extract
of a seed from a scrub palm that grows naturally in the southeastern
United States -- poses any long-term safety hazard to users.

"So, if people are taking this and feel like they are getting some
benefit, I think it's worth continuing," Bent said.

He noted that the science on the efficacy of saw palmetto for BPH has been
ambiguous, with some studies suggesting a benefit and others finding it to
be of no help at all.

"Those studies were of short duration, however, or they didn't use what is
now the standard measure of symptoms," Bent said. "They also didn't report
on what we call the 'adequacy of blinding' -- we never knew in these prior
studies whether patients in the placebo group knew they were on placebo or
not."

His team sought to redress a lot of those issues, taking special care to
ensure proper blinding and using a pool of patients large enough to gain
sufficient statistical power.

They also went to great lengths to choose a top-notch product -- in this
case, a brand of saw palmetto capsules marketed in the United States by
Rexall-Sundown Co. "We had an external advisory committee from the
National Center for Complementary and Alternative Medicine, experts in the
field, who evaluated a number of different extracts," Bent said. "They
felt this was the best one."

Rexall-Sundown did not respond to requests for comment.

In the trial, the researchers tracked the symptoms of 225 men over the age
of 49 with moderate-to-severe BPH. Half of the men took 160 milligrams of
saw palmetto twice daily, while the other half took an inactive placebo.

At the one-year mark, the researchers found no difference between the two
groups in terms of symptom scores, urine flow rates, prostate size,
quality of life, or blood levels of prostate-specific antigen (PSA), a
marker for enlarged prostate.

Morton agreed with Bent that saw palmetto is probably safe for users. But
he questioned whether too many men plagued by enlarged prostate are using
this ineffective remedy in lieu of conventional drugs whose efficacy has
long been supported by clinical research.

"There are two medications that we commonly use for men with BPH," said
Morton, who is also chief of the division of urology at Robert Wood
Johnson Medical School at the University of Medicine and Dentistry of New
Jersey. "One includes drugs called alpha blockers, and the other group is
5-alpha-reductase inhibitors. Alpha blockers cause a relaxation of the
prostate that makes it easier for a man to urinate. And 5-alpha-reductase
inhibitors shrink the prostate."

Either of these medications might be more effective than over-the-counter
saw palmetto, Morton said.

He held out the possibility that formulations other than the
Rexall-Sundown brand used in the study might still be of benefit to some
users. "I do believe, though, that the investigators went to great lengths
to ensure the purity of the compound that they were testing," he said.

In a statement, Andrew Shao, vice president of the Council for Responsible
Nutrition, a supplements industry trade group, called the findings
"puzzling, given that more than 20 studies have shown promising findings
for saw palmetto in alleviating symptoms commonly associated with prostate
problems."

He agreed the study was "well-designed," but blamed its negative findings
on the researchers' focus on patients with moderate-to-severe BPH.
According to Shao, the bulk of the positive literature on saw palmetto
involves men with milder symptoms.

"The exclusion of those patients with mild symptoms from the study may
have reduced [its] ability to detect the benefits we've seen in other
trials," he said.

A much bigger issue, according to Bent and Morton, is the lack of
regulation and oversight of herbals and other alternative medicines, which
are not tested or checked for quality by the U.S. Food and Drug
Administration in the same way that conventional drugs are.

"There are millions and millions of men out there who take saw palmetto,"
Morton said. "And if you review the literature on saw palmetto, it's
really all over the map. Quite frankly, I'm not certain that the FDA would
approve it -- I'm pretty certain they would not. But it's simply not held
to the same standard."