Saw Palmetto Disappoints

As many as two million US men with prostate problems have taken saw palmetto extract, which is a widely-used treatment for benign prostatic hyperplasia, or prostatism as it’s sometimes called. Earlier studies had showed that different preparations of saw palmetto improve the symptoms of prostatism, as compared with placebo, having a benefit similar to that from finasteride (Proscar®) or terazosin (Hytrin®), both of which are FDA-approved for this use.

In 2000 the FDA denied an application for a health claim that saw palmetto was an effective treatment for prostatism, because of “the public health importance of ensuring that claims to treat disease be substantiated by the appropriate level of evidentiary support to provide protection for patients who are already sick and, therefore, especially vulnerable”.

Now a new study has been published in the New England Journal of Medicine that shows the opposite effect - saw palmetto turned out to be no better than placebo over 12 months of treatment. How to explain the difference to earlier studies? The authors of the study suggest that their trial was larger, longer, and more detailed than others. Moreover, they took great pains to have a truly matching placebo; saw palmetto has a very pungent smell, which may have invalidated the ‘blinding’ of earlier studies.

What’s a man with prostate symptoms to do? If he’s taking saw palmetto and it seems to be working, he should carry on, until more evidence has accrued. If it’s not working, he might as well stop it and save his money. There are alternative safe and effective treatments for prostatism.