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 processing plant.

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.

Q. Berry or extract?
A. When you purchase saw palmetto, you will find some bottles that provide crushed berries, not the extracts. Until we learn more about the effects of using the full contents of the berries, I recommend that you buy the extracts. The extracts will contain the actual substances that are effective in treating BPH in a much higher concentration. The berries will provide you with smaller amounts of the needed active ingredients. Whether the crushed berries have compounds that provide other benefits is not fully known at this time. If you want to take the berries, you may need to ingest at least one or two grams a day. The ratio of the dried berry to the lipophilic extracts is usually about 10 to 1. Some users prefer to take both the extracts and the berries, thinking that there are substances within the full berries that could be beneficial. We certainly need more research in order to have a fuller understanding.

Q. What about standardizing saw palmetto products?
A. Since there are hundreds of substances within saw palmetto, it would be difficult to standardize extracts. How can one product be compared to another? Which compounds within saw palmetto could serve as markers? Dr. McLaughlin believes that the monoacylglycerides monolaurin and monomyristin could serve as marker compounds since they are not easily found in other herbs or plants. They could easily be evaluated in a laboratory by a process known as HPLC (high performance liquid chromatography). Thus, by knowing the amounts of these compounds, it would be easier to standardize different products. Beta-sitosterol, one of the plant sterols in SP, may not be a good marker since many other herbs contain this sterol. St. John's wort is now often standardized by its content of hypericin. For instance, most bottles will say on them that the product contains 0.3 percent hypericin. saw palmettoP products do not have this standardization, but you will find that most bottles will say that they contain 85 to 95 percent of a liposterolic extract. Liposterolic is a general term that encompasses the varieties of fat-soluble compounds within SP. The standardization of saw palmetto products is not likely to occur soon.

Q. Is There a major difference between different trademarked products?
A. Donald Brown, ND, the author of Herbal Prescriptions for Better Health, (Prima, 1996) says, "The active compounds within saw palmetto can be extracted in a variety of ways. The most common is using hexane (a volatile, colorless, liquid hydrocarbon with 6 carbon atoms). The French Company Pierre Fabre Medicaments uses this process for their product Permixon. Another product, called Strogen Forte, contains extracts removed by carbon dioxide. Some vitamin companies will say on their bottle "Non-hexane extract." Frankly, both ways are fine and I don't see any problems with either method of extraction. Hexane is the traditional way to extract fatty acids, oils and sterols from herbs, seeds and berries. Ethanol can also be used for extraction.

"It's possible that the constituents of the different products may be slightly different based on the method of extraction, however, for practical purposes, their effect on the human prostate should not be too different."

I tend to agree with Dr. Brown. For the time being, and for practical purposes, it's okay to consider most of these products as near equivalent.

Q. How quickly does saw palmetto get absorbed?
A. When you swallow a SP capsule or tablet, it will go into the gastrointestinal tract, be absorbed from the intestines, and make its way to the blood in about an hour or two. The liposterolic extracts have been found to stay in the blood for a few hours. During this time, a number of compounds within the saw palmetto extract will make their way to various parts of our bodies, including skin, hair follicles, genital tissues, and prostate. Studies in rats show that higher concentrations of saw palmetto are eventually found in the prostate gland as compared to other tissues (Plosker, 1996).

Saw palmetto is best taken with meals since it is fat-soluble. Most of the time, the recommended dosage is one pill twice a day. However, a higher dosage of 320 mg taken once a day is also an option.

Q. For which conditions is saw palmetto useful?
A. The best known use of saw palmetto is for the treatment of prostate enlargement. However, there's a possibility that substances in saw palmetto could have an influence on a variety of body tissues. They may even have anti-tumor potential. I'll review the research discussing these influences in a later chapter.

It appears that urinary symptoms due to mild to moderate prostate enlargement respond more readily to saw palmetto than symptoms due to severe enlargement (Ebbinghaus, 1995).

Q. How does saw palmetto work?
A. Unfortunately, many herbal and natural medicines have had far less research money devoted to them than they deserve. SP is no exception. Consequently, we don't know all the answers to the exact mechanisms of how the different compounds within SP work. However, there have been enough studies to give us some clues. Some of most likely mechanisms include the reduction in the amount of dihydrotestosterone (DHT) in prostate tissue, inhibition of binding of DHT to androgen receptors in prostate cells, and the anti-estrogenic action in prostate tissue. I will discuss the studies supporting or refuting these claims in greater detail in a later chapter. Unlike a particular medicine, such as Proscar, which has one active ingredient, saw palmetto has a number of different compounds within it. Thus, you can see why it would be complicated to evaluate all the possible interactions that these compounds have on a variety of tissues within our bodies. Furthermore, it is possible that a single compound within saw palmetto may not have much of an influence on its own although its combination with the other compounds would have a synergistic effect. The more I learn about the human body, the more I realize how complicated it is. Early in my medical career I often unquestioningly accepted the results of studies done in a laboratory or on animals and was quick to use this information to generalize to humans. I now know otherwise. In order to understand truly how a medicine works, it has to be studied directly on humans. Although laboratory and animal studies can give us important information, they are never a replacement for thorough human evaluations. Another complicating factor is that modern medicine does not advance solely on the basis of seeking the most efficient therapy for human diseases. There are significant economic factors that influence the funding of studies, the subsequent interpretation of the results, and especially the dissemination of this information. Many of the studies done with saw palmetto were financed either by companies who market this extract, such as Pierre Fabre Medicament, or by pharmaceutical companies, such as Merck, who have developed competing drugs that treat prostate enlargement. Merck has the drug Proscar. Not surprisingly, the results of studies obtained by Merck scientists on the method of action of saw palmetto are often in marked disagreement with the results obtained by scientists working under the auspices of saw palmetto-selling companies. Full details are provided later.

Q. Is there info available re taking saw palmetto along with perscription meds such as high blood pressure meds?
A. As far as we know, saw palmetto does not interfere to any clinical degree with other medicines.

Ray Sahelian, M.D., is a physician certified by the American Board of Family Practice. He resides in Marina Del Rey, California.

Reference: Smith W, Mitchell P, Leeder SR. Dietary fat and fish intake and age-related maculopathy. Arch Ophthalmol 2000 Mar;118(3):401-4; National Centre for Epidemiology and Population Health, Australian National University, Australian Capital Territory