Saw Palmetto-Medicinal Actions, Uses, and Cautions

Saw palmetto, whose botanical name is serenoa repens, is a member of the palm family. It grows in the southeastern United States, especially in the Florida Everglades. The Seminole Indians originally consumed it as a food, but today it’s more popular for its use in the treatment of a condition affecting many men over the age of 50-benign prostatic hyperplasia (BPH).

BPH is caused by overgrowth of the cells of the prostate gland, which is present only in men and which surrounds the urethra. When the prostate enlarges it puts pressure on the urethra, making it difficult for the bladder to empty completely during urination. This can cause frequent trips to the bathroom, especially at night, which is certainly an inconvenience (to say the least). But if the prostate continues to grow it can eventually block the urethra, possibly causing bladder and kidney damage and requiring surgery.

The overgrowth of prostate cells is itself caused by an increase in the levels of a hormone called dehydrotestosterone (DHT). DHT is formed when the male hormone testosterone reacts with the enzyme 5-alpha-reductase.

Medical science has developed a drug called finasteride (Proscar) which inhibits 5-alpha-reductase, thereby decreasing DHT levels and reducing prostate growth. What’s interesting is, in clinical trials in Europe, an extract of the berries from the saw palmetto plant had the same-or slightly better-effect on 5-alpha-reductase as finasteride.

It’s uncertain which components of saw palmetto produce this effect. Saw palmetto contains many plant sterols, including beta-sitosterol, campesterol, and stigmasterol, that may be responsible, but there are other chemicals that may also contribute. Herbs, like all plants, have many different chemical components which tend to work together, so there is probably no one “active ingredient.”

Besides inhibiting 5-alpha-reductase, saw palmetto blocks estrogens (men have these too) and DHT that’s already present from acting on prostate cells. It also seems to decrease the inflammation that occurs with BPH. And it has a couple of advantages over the prescription drug-it has fewer side effects, and it works faster. Finasteride can take up to six months to have an effect, but saw palmetto usually works within three months.

Finasteride has one other effect that was discovered during clinical trials: It can decrease hair loss from male pattern baldness (another effect of DHT). It’s been theorized that since saw palmetto works in the same way, it would have the same effect, and this has been observed, but not during formal research.

Saw palmetto may also be useful for kidney problems, diarrhea, bronchitis, and digestive problems. In women, it may be used to relieve the symptoms of cystitis (bladder infection), and to encourage breast growth and lactation.

However, since saw palmetto works in the same way as finasteride, it may have some of the same side effects-reduced libido, erectile problems, decreased ejaculate, and breast growth and tenderness. But in another study, during which saw palmetto was compared to finasteride, only 1.1% of the men who took it experienced erectile problems, while 4.9% of the men taking finasteride had them.

There is one other caution to keep in mind. 5-alpha-reductase inhibitors can interfere with tests for prostate specific antigen (PSA), an indicator of a man’s risk of prostate cancer. Men who are considering taking saw palmetto (or finasteride) for BPH should have their PSA level checked first.

BPH can affect a large number of men over 50-up to 90%. With these statistics, the preventive effects of saw palmetto might be worth considering.