Saw Palmetto Shrinks Prostate Tissues
In the first American randomized clinical trial of saw palmetto
(Serenoa repens [Bartr.] Small, Arecaceae), the respected
prostate herb proved beneficial in reducing swelling of prostate
tissues in patients with benign prostatic hyperplasia (BPH). While
numerous studies have confirmed the ability of saw palmetto extract
(SPE) to reduce BPH symptoms, this is the first evidence that
it actually shrinks enlarged prostate tissues (Overmyer, 1999).
The randomized, double-blind, placebo-controlled clinical trial
involved 44 men with symptomatic prostate enlargement who took
320 mg of saw palmetto extract with nettle root extract or placebo
for six months (Nutrilite® Saw Palmetto with Nettle Root,
Nutrilite Division of Amway, Ada, MI). Researchers tested the
participants for the usual clinical parameters, including International
Prostate Symptom Score (IPSS), maximum urinary flow rate, residual
urine volume, prostate volume, and prostate specific antigen (PSA,
described below). Unlike previous research, this study included
an ultrasound-guided prostate biopsy, allowing the scientists
to assess changes in the participants' prostate tissue. Biopsies
were taken at baseline and after six months of treatment.
As with previous research, SPE proved effective (or "somewhat
effective," according to the researchers) in reducing overall
symptom score and maximum urinary flow. Although symptom score
(IPSS) dropped in the SPE group, it dropped similarly in the placebo
group (2.9 and 2.6 respectively). The urinary flow rate increased
in the SPE group while declining in the placebo group. There were
no effects on hormone levels or other blood parameters.
The most intriguing part of this story is that SPE suppressed
swelling of the prostate epithelium, causing a contraction in
the tissues in the epithelium of the prostate and the transitional
zone. Interestingly, SPE produced this benefit without affecting
the levels of testosterone or dihydrotestosterone, which means
that SPE works by an unidentified but non-hormonal mechanism.
This is especially good news for men because conventional drug
therapy for BPH frequently causes hormonal side effects, including
reduced sex drive and performance. It should also be good news
for doctors, because SPE did not affect the level of PSA in the
blood. PSA tests are used to detect prostate cancer, and conventional
therapy interferes with PSA testing by masking this early warning
sign.
An editorial by Leonard Marks, M.D. accompanying the research
report should provide perspective for physicians still uncertain
about herbal therapies. "Saw palmetto extract (SPE) should
now be considered a treatment option for men with symptomatic
BPH, absent complications of the disorder. SPE is extremely safe;
it is likely to exert positive effects; many patients want it;
and more potent remedies, i.e., drugs or surgery, are generally
not required in most BPH cases." Marks points out that saw
palmetto has been used in Europe for generations, that its safety
"has never been seriously questioned," and with the
exception of occasional stomach upset, no side effects have been
reported. "In particular, use of the extract has not been
associated with erectile dysfunction, ejaculatory disturbance,
or altered libido." - Rob McCaleb
[Overmyer M. Saw palmetto shown
to shrink prostatic epithelium. Urology Times 1999; 27(6):
1,42.] |
