Saw palmetto fruit extracts are widely used for treating lower urinary tract symptoms attributed to benign prostatic hyperplasia. However, recent clinical trials have questioned their efficacy, at least at standard doses (320 mg daily).
To determine the effect of a saw palmetto extract at up to three times the standard dose on lower urinary tract symptoms attributed to benign prostatic hyperplasia.
Multicenter placebo-controlled randomized trial conducted from June, 2008 through October, 2010.
Eleven North American clinical sites.
Were men at least 45 years old, with a peak urinary flow rate ≥ 4 ml/sec, an AUA Symptom Index (AUASI) score ≥ 8 and ≤ 24, and no exclusions.
One, two, and then three 320 mg daily doses of saw palmetto extract or placebo, with dose increases at 24 and 48 weeks.
Main Outcome Measures
Primary outcome was the difference in AUASI score from baseline to 72 weeks. Secondary outcomes were measures of urinary bother; nocturia; uroflow; postvoid residual; prostate-specific antigen; participants’ global assessments; and indices of sexual function, continence, sleep quality, and prostatitis symptoms.
From baseline to 72 weeks, mean AUASI scores decreased from 14.4 to 12.2 points with saw palmetto and from 14.7 to 11.7 points with placebo. The group mean difference in AUASI score change from baseline to 72 weeks between the saw palmetto and placebo groups was 0.79 points favoring placebo (bound of the 95% confidence interval most favorable to saw palmetto was 1.77 points, one-sided P=0.91). Saw palmetto was no more effective than placebo for any secondary outcome. No attributable side effects were identified.
Increasing doses of a saw palmetto fruit extract did not reduce lower urinary tract symptoms more than placebo. (CAMUS study number NCT00603304 http://www.ClinicalTrials.gov)