Saw palmetto fails to relieve BPH symptoms in new Harvard study

A new study published in The Journal of the American Medical Association finds that saw palmetto, a fruit extract commonly taken to treat urinary tract symptoms caused by an enlarged prostate (technically termed benign prostatic hyperplasia, or BPH), is no more effective in relieving symptoms than placebo, even at high doses.

The federally funded study included nearly 370 moderately symptomatic men over age 45 from 11 North American hospitals. Over 72 weeks, the participants took a daily dose of either saw palmetto or a placebo. The standard dose of 320mg/day of saw palmetto was tripled over the course of the study. Despite this increase, at the end of the study period, saw palmetto did not relieve urinary tract symptoms any more than the placebo. These findings are consistent with findings from a one year trial in 2006 that also found no benefit of saw palmetto to patients with BPH symptoms.

A large majority of men have symptoms of an enlarged prostate at some point after age 50, which include frequent urination – including the need to visit the bathroom several times at night – difficulty urinating, and weak or intermittent urinary flow. While these symptoms are mild in some men, they are severe enough to interfere with quality of life in others. Medications to treat BPH are available but many can produce unpleasant side effects. Prior to this study, saw palmetto was thought to be a low-cost, safer alternative.

Study author and clinical professor of Medicine at Harvard Medical School, Michael Barry, MD, concludes “Saw palmetto extracts are commonly used by men with bothersome lower urinary tract symptoms, but our results indicate that the particular extract we tested was no better than a placebo at relieving those symptoms. It is possible that other formulations could be helpful, but a number of recent studies with negative results suggest it may be difficult to find a saw palmetto extract that is better than placebo.”