Taking saw palmetto, an herbal supplement used to decrease symptoms of enlarged prostates, may have no intended health effects, according to new research released Tuesday. Even taken in high doses, researchers found the dietary supplement long believed to aid men's prostate health was not any better than a placebo.

The berry from the American dwarf palm tree still has its supporters including the Natural Products Association, a trade organization that represents herbalists. The new research echoes previous research from 2006 that came to the same conclusion.

Men take saw palmetto to relieve the symptoms related to benign prostatic hyperplasia, enlargement of the prostate and subsequent symptoms such as hair loss, coughs and urinary tract infections. Its crude extract has been used in traditional, eclectic, and alternative medicine for hundreds of years.

The new multi-center study led by Michael Barry at Massachusetts General Hospital in Boston and colleagues found that saw palmetto was no better than a placebo at relieving prostate problems, as well as related symptoms.

It is possible that other formulations could be helpful, but a number of recent studies with negative results suggest it may be difficult to find a saw palmetto extract that is better than placebo, said Barry, who is also a clinical professor at Harvard Medical School.

The researchers published their work Wednesday in the Journal of the American Medical Association.

The double-blind study included a group of 369 men aged 45 and older with moderate symptoms suggestive of an enlarged prostate. Over 17 months, as one group took a daily dose of saw palmetto extract, the other took an identical-looking placebo pill with the same distinctive smell and taste. Researchers doubled the initial saw palmetto dosage after 24 weeks and tripled dosage after another 24 weeks.

Researchers found no difference between the two groups, but prostate problems improved slightly for both.

We commonly see this in clinical trials, said co-author Gerald Andriole, professor and chief of urologic surgery at Washington University School of Medicine in St. Louis. Patients often report an improvement in symptoms because they are taking something, even if it is a placebo. But in this study, there was no benefit to taking saw palmetto over the placebo.

Those in the herbal supplement industry disagreed with the researchers' conclusions.

Saw palmetto extract is a safe alternative for men suffering from urinary tract symptoms and many see positive results, Cara Welch, vice president of scientific and regulatory affairs for the Natural Products Association, stated in an email response to IB Times. As the authors suggest, their results cannot be generalized across all preparations and additional research might be necessary to uncover the mechanism of action for saw palmetto.

The largest previous research conducted in 2006, involving 225 men over 50, found that a standard dose of 160 mg twice a day for one year performed no better than placebo at relieving symptoms.

While numerous earlier studies suggest positive effects from saw palmetto, the new study has a greater credibility, according to Barry. 

First, the dose of saw palmetto is higher, Barry told IBTimes in an interview. An earlier study in 2006 that also showed a negative result did not address the effectiveness of higher doses.

Second, we used a well characterized extract of saw palmetto, and third, the patients were collected from 11 different centers, in order that the results may be more randomized, according to Barry. 

It's a tough question whether to recommend saw palmetto, Barry said, since it is hard to show that saw palmetto is better than the placebo.
Since both saw palmetto and the placebo showed 40 percent improvement in the symptoms, with no or little side effect even in high dose, I would tell a patient interested in trying saw palmetto that I wouldn't object, said Barry. But they should know that it doesn't look like it works better than the placebo.