NEJM 27203

NEJM: Saw Palmetto No Benefit to BPH; Industry Associations Clarify Study Parameters

SAN FRANCISCOAstudy funded by the National Institute of Diabetes and Digestive and KidneyDiseases and the National Center for Complementary and Alternative Medicine(NCCAM) found saw palmetto (Serenoa repens) had no more effect thanplacebo in men with moderate to severe symptoms of benign prostatic hyperplasia(BPH). Reported in the Feb. 9 issue of the New England Journal of Medicine (354,6:557-66, 2006), the trial also reported while mild adverse effects wererelatively equivalent between the saw palmetto and placebo groups, there weresignificantly more serious adverse effects reported by those taking placebo. Theherbal and nutritional products industry challenged application of theseresults, based on study parameters and the wealth of past positive results onthe efficacy and safety of saw palmetto and BPH.

In the NEJM study, researchers from the University of California, SanFrancisco, randomly assigned 225 men aged 49 or older with moderate to severeBPH into two treatment groups112 men took either 160 mg twice daily of aleading saw palmetto extract, while 113 men took placebo doses. Over the courseof a one-year period, patients made eight study visits, during which researchersassessed changes in AUASI (American Urological Association symptom index)scores, maximal urine flow, postvoid residual urine volume, prostate size andother health-related outcomes. On average, improvements were recorded forpatients in both study groups, as measured by AUASI, but there were nosignificant differences between the two groups relative to improvement in BPHsymptoms.

Mark Blumenthal, founder and executive director of ABC, explained sawpalmetto is widely recognized for its safety and efficacy in treating mild tomoderate symptoms associated with BPH, a non-cancerous swelling of theprostate gland in older men that can result in various symptoms associated withthe interruption of normal urinary flow.

Our primary concern with this trial is the relatively advanced conditionof the prostate problems in many of the men who were tested, he said, noting the men in this latest study had advanced to severeBPH, in contrast to most of the previous controlled trials showing positiveresults and efficacy for saw palmetto in men with mild to moderatesymptoms. Most of the official international monographs that recognize thebenefits of saw palmetto do so for stage 1 and 2 of BPH, i.e., the mild tomoderate range of BPH symptoms, said Blumenthal. These include monographsfrom the German government and the World Health Organization (WHO). Thus, headvised the results of this trial be seen in the perspective of thepreponderance of the existing evidence, including at least 21 controlled trialsshowing positive outcomes with saw palmetto preparations.

Both Blumenthal and Andrew Shao, Ph.D., vice president of the Council forResponsible Nutrition (CRN), agreed the NEJM study was well-designed andused a high-quality saw palmetto extract at the dosage shown effective in 21controlled trials. Shao said exclusion of patients with mild BPH might havereduced the ability to detect the benefits of the herb, while Blumenthalsuggested a third arm involving higher dosages could have tested doseresponse atanother level. That there were almost twice as many serious adverse effects inthe placebo group compared to the saw palmetto group in the NEJM trial,Blumenthal added, suggests the patient population may have had other seriousillnesses, possibly interfering with the attempt to treat the moderate-tosevereBPH symptoms.

In further defense of saw palmetto, Blumenthal cited a Cochrane Databasereview that revealed 21 clinical trials involving more than 30,000 men with mildto moderate BPH concluded saw palmetto was safe and effective compared to eitherplacebo and drug (finasteride, aka Proscar®) treatment, with fewer side effectsthan the drug. Based on this wealth of positive research, saw palmetto has beenapproved as a safe and effective BPH treatment by the German governmentsrespected Commission E as well as by the Canadian governments Natural HealthProducts Directorate. The herbal remedy has also been accepted in Western Europeby way of a monograph by the European Scientific Cooperative on Phytotherapy(ESCOP), which acknowledges its efficacy for symptomatic treatment ofmicturition (urinary) disorders in mild to moderate BPH. Likewise, WHOacknowledges the efficacy of saw palmetto for treating lower urinary tractsymptoms secondary to stage 1 and 2 BPH.

Michael McGuffin, president of the American Herbal Products Association(AHPA) also expressed concerns about the NEJM study results, which hesaid failed to corroborate earlier research. Numerous other well-designedstudies have shown significant benefits with the same dosage range and similar,or in many cases, more representative populations. It is important to evaluatethe results of this new data in the context of these earlier results.