Saw palmetto has flunked again in a trial of claims that it can reduce symptoms of benign prostatic hypertrophy (BPH)-even at levels three times the standard dose. Given recent findings from the STEP study that extracts from the saw palmetto dwarf palm tree were ineffective at standard doses, researchers at Northwestern University and 10 other sites tested escalating levels. The randomized trial involved 369 men, average age 61, suffering from BPH, an enlargement of the prostate that can impair bladder function. Over three periods of 24 weeks each, doses of saw palmetto were increased from the standard 320 milligrams daily to triple that dose. Even at the highest dosage, there was no significant difference in scores on the American Urological Symptom Index between those receiving saw palmetto and those on placebo; men in the placebo group actually showed slightly greater improvement. Scientists concluded that this and other recent trials make it increasingly unlikely any saw palmetto extract will prove more effective than placebo.
TO LEARN MORE: JAMA, Sept. 28, 2011; abstract at jama.ama-assn.org/content/306/12/1344.abstract.