Saw palmetto is an herb that has been shown in clinical studies to have
beneficial effects in reducing symptoms of benign prostatic hyperplasia.Ê
Q. What's in saw palmetto?
A. There are a variety of compounds within the saw palmetto berry (Fitzpatrick,
1995). As a rule they are divided into four major categories:
1) Free fatty acids. Quite a number of fatty acids are present in saw palmetto. The ones in highest concentration include oleic acid, lauric acid, myristic acid and palmitic acid.
2) Phytosterols (plant sterols). These plant sterols (phyto means plant)
have a chemical structure similar to cholesterol. The most commonly found
phytosterols in saw palmetto are beta-sitosterol, campesterol, stigmasterol
and cycloartenol (Plosker, 1996).
3) Free fatty alcohols. These are usually made up of fatty acids joined to
an alcohol molecule.
4) Monoglycerides, which are single fatty acids attached to a three-carbon
glycerol molecule (Shimada, 1997).
All of these are fat-soluble. The process of extracting these compounds from
the berry involves mostly three methods. The most common are the use of
hexane solvent, carbon dioxide, and ethanol.
According to Dr. Jerry McLaughlin, Professor of Pharmacognosy,
Department of Medicinal Chemistry and Molecular Pharmacology at Purdue
University in West Lafayette, Indiana, there are probably more active
compounds in saw palmetto than we know of at this time. Dr. McLaughlin has
personally analyzed some of these compounds at his University laboratory. He
says, "There are hundreds of substances in herbal extracts, and it's going
to take a very long time for us to isolate the biologically active ones. It's
like trying to find a needle in a haystack. For instance, we have isolated
two monoglycerides within saw palmetto that have anti-tumor activities.
These are 1-monolaurin, and 1-monomyristin. I'm sure there are others."
The active ingredients in saw palmetto are fat-soluble and are thus
extracted from the berry. The extracts you buy in vitamin stores, pharmacies, or
retail outlets should contain 85% to 95% standardized extract of these fatty acids and sterols (they're called 'liposterolic' extracts). Unfortunately, not all products will be identical since the extraction process varies from
laboratory to laboratory. The final constituents of the extracts depend on a
number of factors. These include which type of solvent is used in the
extraction process, the time of year the berries are harvested, the type of
soil the palm trees are grown in, and the skill of the technicians at the
Dr. McLaughlin strongly believes that the time of year a plant, flower, or
berry is picked makes a difference in the content of the active ingredients.
"We did a field study collecting paw paw plants (also known as Indiana
bananas) every two weeks throughout the year. We found the peak in activity
of the compounds to be between May and July. Much of the folkloric use of
plants and herbs developed as a consequence of trial and error. Healers
learned with time that there were specific periods throughout the year that
a particular plant had its most active ingredients.
"Therefore, if a plant is improperly grown, or harvested at an off time, it
would either not have the same active ingredients, or have a different set
of ingredients that would work in the body a different way."
Let's also keep in mind that almost all of the studies done with saw
palmetto extracts have used the European trademarked product Permixon (a hexane
extract), or Strogen (a carbon dioxide extract). The saw palmetto products
that you buy over the counter may have liposterolic extracts that are
similar to these trademarked products, or perhaps slightly different. If the
contents of over-the-counter saw palmetto products are different, they may have more active ingredients, or fewer active ingredients. Unfortunately, these are
some of the uncertainties we have to deal with when using plant extracts
that are not fully standardized. Herbal medicine is not yet a pure science.