Saw palmetto shows no benefit in study of men with BPH

May 26, 2005

Conflicting with results of previous trials, saw palmetto showed no effect on urinary symptoms or objective measures of BPH in a study reported at the AUA annual meeting yesterday.

Conflicting with results of previous trials, saw palmetto showed no effect on urinary symptoms or objective measures of BPH in a study reported at the AUA annual meeting yesterday.

After a year of treatment, BPH patients treated with saw palmetto or placebo had similar declines in AUA symptom inventory (AUASI). Additionally, the two treatment groups did not differ with respect to changes in maximal urine flow, post-void residual volume, or prostate size.

"We observed no evidence of benefit in AUA symptom score, maximal flow, or other measured outcomes with saw palmetto treatment," said Katsuto Shinohara, MD, of the University of California, San Francisco. "However, there was no evidence of harm or safety concerns with saw palmetto."

The study involved 225 men at least 50 years of age with AUASI scores between 8 and 35. The patients were randomized to saw palmetto, 160 mg twice daily, or to a matching placebo and followed for a year, during which time each patient had eight clinic visits.

Patients in both groups improved during follow-up. AUASI declined by an average of 1.0 in the saw palmetto group and by 0.8 in the placebo group, a difference that was not statistically significant. Improvement in maximal flow rate averaged 0.6 cc/sec with saw palmetto and 0.2 with placebo. Changes in prostate volume, post-void residual, BPH index, and overall O'Leary score were similar between treatment groups. Serious adverse events occurred in 26 patients with no difference between groups.

Dr. Shinohara noted that a majority of 14 prior placebo-controlled trials of saw palmetto demonstrated some degree of benefit in BPH patients. He said the discrepancy between the current findings and the earlier studies needs to be explored.