reviewed by X. Li, Ph. D.
(credential)
Continued from
Saw Palmetto for benign prostatic hyperplasia (BPH) (1)
Most trials studying the health benefits of saw palmetto have been conducted in Europe.
So far only two saw palmetto trials done in USA have been published1, 2. They were done by researchers from
University of Chicago Pritzker School of Medicine and University of California Los Angeles School of Medicine.
In the first study1, 44 men of 45 to 80 years old with symptomatic BPH were randomized to receive
either saw palmetto or placebo for 6 months. Saw palmetto is a standardized saw palmetto extract in 106 mg soft capsules taken three times
a day with meals (106 x 3 = 318 mg in total daily). Placebo is indistinguishable from saw palmetto preparation.
Whether a patient took saw palmetto or placebo is sealed for both patients and physicians till the end of
study. As trial outcomes, patients were measured with the International Prostate Symptom Score (I-PSS),
urine flow rate, post-void residual urine volume, and other blood tests. The measures were done at the start,
in the middle, and the end of trial.
As a result, the authors found that patients receiving both saw palmetto and placebo showed some improvement of
BPH symptoms. Saw palmetto gave a bigger improvement than placebo but the difference has not yet reached
the level of statistically significance. No change in levels of PSA (prostate specific antigen) and sex hormone
was seen. However, the authors found some noticeable change in the prostate structure, namely epithelial
contraction in the so-called transition zone. The relevance of this change to improvement of BPH is yet to be established.
No adverse effect was noticed in the trial.
The second trial2 was conducted similar to the first one. However, 85 patients were LUTS instead of BPH.
LUTS patients are loosely defined by their symptoms and they may or may not be BPH (see more).
The patients took 160 mg standardized saw palmetto extract twice a day for 6 months. At the trial end,
patients receiving saw palmetto had their I-PSS score improved 4.4 points from 16.7 to 12.3 (the smaller the better)
This was compared with the 2.2 points improvement from 15.8 to 13.6 in
patients taking placebo. The difference is statistically significant. No other measures showed
significant difference between the two groups although the saw palmetto group felt a better quality of life.
In summary, saw palmetto trials in USA are still very limited in size and scale compared to European studies.
The USA trial results are less conclusive but are in line with the much larger trials in Europe that support
the positive effect of saw palmetto in relieving BPH or LUTS symptoms and thus in maintaining prostate
health. More studies are being sponsored by NIH (National Institute of Health).
Saw Palmetto for benign prostatic hyperplasia (BPH) (1).
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Saw palmetto was also compared with Proscar for BPH.
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Reference
1. Marks LS, Partin AW, Epstein JI, Tyler VE, Simon I, Macairan ML, Chan TL, Dorey FJ,
Garris JB, Veltri RW, Santos PB, Stonebrook KA, deKernion JB. Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic
hyperplasia. J Urol. 2000 May;163(5):1451-6.
2. Gerber GS, Kuznetsov D, Johnson BC, Burstein JD. Randomized, double-blind, placebo-controlled trial of saw palmetto in men with
lower urinary tract symptoms. Urology. 2001 Dec;58(6):960-4.
