Effective or not, the saw palmetto?
February 23, 2006 – The New England Journal of Medicine has just published a clinical trial whose results indicate that a saw palmetto extract is ineffective in relieving the symptoms of benign prostatic hyperplasia. These data contradict the results of previous studies.
The trial was conducted over a 12-month period in 225 men aged 50 and over with benign prostatic hypertrophy. Half of the subjects were given 160 mg of saw palmetto extract, also known as sabal berry, twice a day. The rest of the patients were taking a placebo.
The results suggest that the extract was not found to be more effective than placebo in relieving symptoms or clinical signs of the disease.
These results cast doubt on the effectiveness of saw palmetto, according to the principal researcher, who however points out that there is no indication that the extract represents any danger for men who take it. He plans to conduct a similar double-blind trial using a higher dosage.
The publication of these results prompted the executives of ConsumerLab.com, an independent laboratory that conducts research on natural health products. In a letter sent to the editor of New England Journal of Medicine, they stress their reservations about the saw palmetto extract the researchers used in the trial. By choosing an extract for their study, they would have checked only the total content of fatty acids and sterols, without ensuring that the 13 substances specific to saw palmetto were present in the right proportions. “It’s certainly a good start, but it’s clearly insufficient to ensure the quality of a saw palmetto extract,” Todd Cooperman, director of ConsumerLab.com, said in a telephone interview.
It is estimated that more than two million Americans currently use saw palmetto extract to prevent or treat benign prostatic hypertrophy, generally in lieu of the synthetic drugs prescribed in conventional medicine for this condition, namely alpha blockers. and 5-alpha-reductase inhibitors.
The results of two reviews of clinical trials involving more than 5 subjects2,3 had previously shown that saw palmetto extract was effective in relieving the symptoms of this condition. The results of a comparative trial even revealed that it was as effective as tamsulosin hydrochloride, an alpha blocker.4.
Note that the trial which has just been published was carried out with funding provided by the US government. Three of the seven researchers, who conducted the study, said they had previously received fees from pharmaceutical companies making synthetic drugs for benign prostatic hypertrophy.
Pierre Lefrançois – PasseportSanté.net
According to Associated Press, New York Times et Globe and Mail.
1. Bent S, Kane C, Shinohara K, et al. Saw Palmetto for Benign Prostatic Hyperplasia, N Engl J Med, 2006 Feb 9;354(6):557-566.
2. Wilt TJ, Ishani A, Stark G, et al. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review, JAMA, 1998 Nov 11;280(18):1604-9.
3. Boyle P, Robertson C, Lowe F, Roehrborn C. Meta-analysis of clinical trials of permixon in the treatment of symptomatic benign prostatic hyperplasia, Urology, 2000 Apr;55(4):533-9.
4. Debruyne F, Koch G, Boyle P, et al; PERMAL study group. [Comparison of a phytotherapeutic agent (Permixon) with an alpha-blocker (Tamsulosin) in the treatment of benign prostatic hyperplasia: a 1-year randomized international study], [Article in French, abstract in English], Prog Urol,2002 Jun;12(3):384-92; discussion 394-4.