Benefits of Supplementation
Saw palmetto is a small, shrubby, palm like plant found in North America
and the West Indies [1-3]. It is found primarily in the coastal and
southeastern regions of the US from the Carolinas to Florida and also
in California [3-4]. Herbal extracts are derived from the dried berry
of the plant [2, 4]. There are a number of extracts available, and the
solvents used include ethanol, methanol, liquid carbon dioxide, and
hexane. The form most widely studied form is Permixon, a hexane extract
[4]. The extracts can contain many compounds, including both free and
esterfied saturated and unsaturated fatty acids such as lauric,
myristic, palmitic, oleic, capric, caprylic, linoleic, linolenic, and
stearic acids, flavanoids, and phytosterols such as beta-sitosterol,
campesterol, and stimasterol. The fatty acids usually make up the
majority of the extract (80-90%), with only a small portion being other
compounds [1, 5].
Saw palmetto is used for prostate support.
In all clinical trials, saw palmetto has been associated with very few
side effects or changes in laboratory parameters [4]. It does not
affect sexual function as finasteride does [11]. Although some trials
report gastric upset, this does not occur with a higher incidence than
placebo, while another source said that this effect may occur, but not
if the saw palmetto is taken along with food [3-4, 15]. There are no
known drug interactions, nor does it interact with the main drug
metabolizing enzymes in humans [4-5]. In a toxicological study, dogs
were fed 2 g/kg daily of saw palmetto for six months and no adverse
effects were observed [4].
Mechanism of Action
Although the evidence for the effectiveness of saw palmetto is strong, the
mechanism of action is still being debated. The most well known is inhibition of
5alpha-reductase (5AR).
What is interesting about the 5AR inhibition caused by saw palmetto is
that it is prostate-specific. Not only does saw palmetto inhibit both
types of 5AR in the prostate but not in other tested tissues
(epididymis, testes, kidney, skin, and breast) in vitro [20], the active
ingredients of saw palmetto concentrate in the prostate as opposed to other
tissues after oral administration to rats [21].
The component or mixture of components responsible for the effects of
saw palmetto has not yet been established [4]. It is likely that the
biological effects of saw palmetto could only be explained by a
combination of ingredients [1]. Some studies indicate that the free
fatty acids may be primarily responsible for some of its activities,
including 5AR inhibition [26-27]. Although it is commonly assumed that
beta-sitosterol is the primary active ingredient in saw palmetto, there
is presently little research to support this, and beta-sitosterol does
not share many of the biological activities of saw palmetto (such as
alpha1 antagonism) [28].
Recommended Dosage & Products
A three month study compared 320 mg once daily and 160 mg twice daily and found
that both treatments were equally effective, so it should only be necessary to
take saw palmetto once a day [29].
One study found that saw palmetto supplements from some brands did not
meet label claims [30]. For this reason, it is important to use a
reliable brand. Now Saw Palmetto is recommended,
and it has been tested by a third party (Consumer Lab) and met label claims.
Jarrow Saw Palmetto
is another good choice.
No part of this article may be reproduced in any form without the permission of David Tolson or Mike McCandless.
