In benign prostatic hyperplasia (BPH) , a man’s prostate gland enlarges. The primary symptoms of BPH vary, but most often involve changes or problems with urination. Severe BPH can lead to more serious problems, including urinary tract infections , bladder or kidney damage, and incontinence. BPH is common in older men, with more than half of men in their sixties experiencing symptoms of BPH and as many as 90% of men in their seventies and eighties.

When BPH symptoms become serious enough, doctors will often prescribe medications to treat it. Other options include using heat (micro- or radio-waves) to destroy the enlarged tissue or removing the tissue surgically. Saw palmetto, an herbal product derived from the American dwarf palm tree, is widely used for treatment of BPH. In fact, it is used in 50% of BPH treatments in Italy and in 90% in Germany.

Although previous studies have reported improvement in BPH symptoms with saw palmetto, many of the studies have been limited by their study design. A well designed study published in the February 8, 2006 issue of the New England Journal of Medicine looked at the use of saw palmetto in men with BPH to determine what, if any, effect it had on the symptoms and signs of BPH.

About the Study

The study enrolled 225 men over the age of 49 who had moderate-to-severe symptoms of BPH. The men were randomly assigned to receive either 160 milligrams of saw palmetto twice daily or a placebo for one year. Neither group of men knew which one they were taking. The primary outcome measures were changes in the score on the American Urological Association Symptom Index (AUASI), which is a self-administered questionnaire that measures symptom severity, and urinary flow rate.

The researchers found that after one year of treatment, there was no significant difference between the two groups of men. The AUASI scores decreased slightly for both groups. The peak urinary flow rate increased slightly for the men taking saw palmetto (+0.42mL) and barely decreased for the men taking placebo (-0.01mL). When the researchers conducted additional analyses on the men, they found that the severity of the BPH symptoms and the size of the prostate gland had no effect on the results.

A limitation of this study is that it tested a specific formulation of saw palmetto. It is possible that a larger dosage or a different preparation may have produced a more significant effect. Also, saw palmetto may still be effective for men with mild symptoms of BPH.

How Does This Affect You?

In most men, the prostate gland begins to slowly grow in size around age 25, which can eventually result in symptoms of BPH. Whereas saw palmetto is frequently used outside the US to treat BPH symptoms, it is not a standard therapy in the US. Given the results of this study saw palmetto is unlikely to become standard care for BPH. Additionally, as pointed out in an accompanying editorial published in the same issue of the journal, herbal supplements like saw palmetto are not held to the same rigorous quality standards as pharmaceuticals, meaning that different preparations of saw palmetto are not guaranteed to have the same or adequate quantity and purity. On the other hand, saw palmetto has not been associated with serious adverse effects, and may still benefit some men with mild cases of BPH.

If you are experiencing BPH-like symptoms, talk with your doctor. There are many options available for treatment, and whatever your decision, your doctor should be kept well informed of your therapeutic choices.