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Product Review:
Saw
Palmetto
Background: Saw
palmetto dietary supplements are primarily used in the U.S. to improve urinary
flow and reduce the frequency and urgency of urination in men with prostate
enlargement (benign prostatic hyperplasia, or BPH). Saw palmetto has also been
used to treat bladder inflammation (cystitis), chronic bronchitis, laryngitis,
and asthma-associated nasal inflammation, among other conditions. Saw palmetto
is actually a type of palm tree, also known as the dwarf palm. Its primary
medicinal value lies in the oily compounds found in its berries.
Most dietary supplements are composed of an
extract from the berries, although crushed berry products are also
available.
Saw palmetto is believed to inhibit the
actions of testosterone on the prostate that cause prostate enlargement and
interference with urinary flow. Among the main constituents of saw palmetto are
fatty acids and sterols. The fatty acids are purported to be responsible for
testosterone-inhibiting effects within the prostate. The mechanism of action of
the sterols is not well understood, although they are present in other herbs
(such as Pygeum bark, stinging nettle root, and pumpkin seed extract) used in
treating prostate conditions. At least 85% of the weight of clinical quality
saw palmetto products are expected to be attributable to specific fatty acids
and sterols.
Currently, saw palmetto and other dietary
supplements are not considered drugs in the U.S. and are not required to be
tested for quality by any governmental or independent agency prior to sale. As
part of its mission to independently evaluate health, wellness and nutrition
products, ConsumerLab.com purchased and tested saw palmetto dietary supplements
sold in the U.S.
Testing & Results:
ConsumerLab.com purchased 27 leading brands of saw palmetto in
November and December 1999, in order to determine whether they possessed the
minimum amounts of specific fatty acids and sterols commonly found in saw
palmetto products used in published clinical trials. Five saw palmetto
products were immediately eliminated from testing as their labels claimed that
they had been standardized to levels of fatty acids that were below 85%. These
products claimed to be standardized to 20-25%, 40%, 45%, 80%, and 80%,
respectively. A sixth product was eliminated as it had incomplete labeling to
determine the amount of saw palmetto per serving.
Among the 21 remaining
products that were tested, four were found not to contain the minimum amounts
of specific fatty acids and/or sterols commonly found in saw palmetto products
used in published clinical trials.
Among these four, all had low fatty acid
levels. In addition, one of these four had low sterol levels and another had no
detectable level of saw palmetto sterols. Among the 17 products that passed,
most contained additional oils that were generally identified as being part of
a "prostate formula." These combinations may or may not have additional
benefit, as they have generally not been clinically tested. Two passing
products appeared to contain exclusively the saw palmetto extract similar to
that used in most clinical trials.
Examples of some of the products that
passed review are:
(Info in order of Product Name, Labeled
Concentration of Saw Palmetto Per Pill, and Manufacturer or
Distributor)
ProstaPro, Saw Palmetto Berry Extract, Standardized
Extract, 160 mg/softgel capsule, PhytoPharmica
Super
Saw Palmetto, 160 mg/softgel capsule, Enzymatic
Therapy
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