New Saw Palmetto Study Fails to Corroborate Earlier Research

(February 9, 2006, Silver Spring, MD) -- A study published in this week's New England Journal of Medicine surprised those who have followed recent research on saw palmetto (Serenoa repens) fruit, as its conclusions run counter to many other clinical studies that have documented the benefits of the herb for managing symptoms of benign prostatic hyperplasia (BPH).

The study (Bent S. et al. Saw palmetto for benign prostatic hyperplasia. NEJM 354(6):557-566) reports that 160 mg of a saw palmetto extract taken twice daily for one year performed no better than placebo for any of the criteria which were evaluated. A total of 225 men with BPH symptoms participated in the study, though men with mild symptoms were excluded. Saw palmetto is usually used by men with mild to moderate BPH.

“This new study needs to be considered in the totality of what we know from clinical research on saw palmetto,” said Michael McGuffin, president of the American Herbal Products Association. “Numerous other well-designed studies have shown significant benefits with the same dosage range and similar, or in many cases, more representative populations. It is important to evaluate the results of this new data in the context of these earlier results.”

A meta-analysis published in 2002 pooled data from 21 saw palmetto studies with a cumulative population of over 3,100 men (Wilt T, Ishani A, MacDonald R. Serenoa repens for benign prostatic hyperplasia. The Cochrane Database of Systematic Reviews 2002;(3):CD001423). The authors of that review concluded that the evidence “suggests that Serenoa repens provides mild to moderate improvement in urinary symptoms and flow measures [and] produced similar improvement in urinary symptoms and flow compared to finasteride [a drug often prescribed for BPH] and is associated with fewer adverse treatment events.”

“We now have pooled data for two hundred additional men,” added McGuffin. “Importantly, this new research recorded no difference in the risk of serious adverse events between saw palmetto users and the placebo group, an observation that lends greater credibility to our long-standing assumption of the safety of this herb.”

Earlier studies have measured a benefit for saw palmetto users who have found a reduction in nocturia (night-time urination). “Curiously, though this symptom was considered as a background factor in Dr. Bent's study, it was not given the emphasis that it should have had given the evidence from prior research and the significance this benefit can have on quality of life,” commented McGuffin.


The American Herbal Products Association (AHPA) is the only national trade association devoted solely to herbal issues. Representing the core of the botanical trade -- comprised of the finest growers, processors, manufacturers and marketers of herbal products -- AHPA’s mission is to promote the responsible commerce of herbal products. AHPA committees generate self-regulations to ensure the highest level of quality with respect to the way herbs are manufactured, labeled, and sold. Website:

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