The herbal remedy saw palmetto can improve symptoms for men with lower urinary tract problems, results of a new study conducted by scientists at the University of Chicago reveal.
Although several smaller and uncontrolled trials of saw palmetto (serona repens) have implied benefits from this herb, many physicians have remained sceptical, the scientists report in a statement.
Men with urinary symptoms spend more than $140 million a year on herbal preparations containing saw palmetto, making it one of the 10 best-selling herbal remedies, they continued.
"Our study provides the best evidence to date that saw palmetto can have a beneficial effect," said Glenn Gerber, M.D., associate professor of surgery at the University of Chicago and director of the study.
Gerber and colleagues at the University of Chicago and at the Dekalb Clinic, in Dekalb, Illinois, enrolled 94 men who complained of urinary retention in the trial. During the first month of the study all participants received a placebo capsule twice a day.
After the first month, nine men who reported considerable improvement were removed from the trial. The remaining 85 men were randomly selected to receive two capsules a day of either saw palmetto (provided by Nutraceutical Corp., Ogden, Utah) or a placebo.
After the one-month placebo "run-in period,' the study subjects filled out a standardised questionnaire about their urinary symptoms, a second questionnaire about sexual function, and a third questionnaire about quality of life. They also had their urinary flow rates measured. The tests were repeated two, four and six months into the trial.
After six months on the medication, the men who received saw palmetto had a 4.4-point decrease (improvement) in their urinary symptom score, from an average of 16.7 down to 12.3. Men who received only the placebo also had a reduction but of only half the size, 2.2 points, from 15.8 down to 13.6.
There were no significant differences between the two groups in the other measurements. Peak urinary flow rates improved slightly in both groups. Self-assessed quality of life improved slightly in both groups. There was no change in sexual function.
"Saw palmetto clearly offers symptomatic benefit as compared with placebo controls," Gerber said.
"We can tell patients that this appears to be a safe, well-tolerated substance that can produce short-term improvement of urinary symptoms,"he continued.
"But we also need to point out that we don't know why it works, and that the dose can vary widely and unpredictably in over-the-counter preparations, which may also include other untested herbal supplements,"Gerber warned.,