Lynn Laboranti, M.S., R.D.
Prostate health is a critical health issue for men. With an eye towards prevention, we talked to Lynn Laboranti, MS,RD, about saw palmetto, a supplement that helps protect the prostate.
What is saw palmetto?
Laboranti: Saw palmetto is an herbal supplement that is used to maintain urinary tract health and prostate health in men. Saw palmetto contains fat-soluble extracts in the berries that are active constituents in this herbal. In particular, saw palmetto is helpful for a condition called benign prostatic hyperplasia (BPH), a noncancerous enlargement of the prostate. This condition is not life threatening; however, it can cause some uncomfortable urinary symptoms such as frequent urination and nighttime awakenings.
How does it help the prostate?
Laboranti: Saw palmetto is useful in treating symptoms of BPH. BPH is a condition that affects more than half of all men over age 60. BPH is an enlargement of the prostate which causes a narrowing of the outlet of the bladder known as the urethra. This results in poor urine flow out of the bladder as well as a host of other symptoms.
Dihydrotestosterone (DHT), an active form of testosterone, is thought to be the culprit behind prostate enlargement. Saw palmetto works by reducing DHT in prostate tissue by blocking the action of 5-alpha-reductase (an enzyme that converts testosterone into DHT). Therefore, it works by protecting the prostate from the irritating effects of testosterone. Saw palmetto has been shown to relieve common symptoms such as increased frequency of urination, increased nighttime urination, and increased urine flow rate, without major side effects. It may take up to 4-6 weeks to see full effect.
It is important to note that saw palmetto is not a treatment for prostate cancer. Prostate specific antigen (PSA) tests are used in part to diagnose prostate cancer. Saw palmetto extract does not seem to interfere with the accuracy of PSA tests. Because BPH and prostate cancer can exist concurrently, men over the age of 50 should see their physician regularly for check-ups.
Is it necessary to take saw palmetto as a prevention of prostate cancer, or only to prevent prostate enlargement?
Laboranti: Saw palmetto is not indicated for treatment or prevention of prostate cancer. Saw palmetto has shown to be effective for maintaining urinary tract health in men and for treating symptoms of BPH. Saw palmetto may also help to maintain a healthy prostate. Once it becomes enlarged, saw palmetto will not cause the prostate gland to shrink.
How much of saw palmetto should men take?
Laboranti: The suggested dose is 320 mg/day of the dried fruit extract taken in divided doses. For example, 160 mg of saw palmetto extract would be taken twice daily with meals.
Should women take saw palmetto?
Laboranti: Saw palmetto use in women has not been well-documented in scientific literature. Some women take saw palmetto in order to increase breast size, however there is minimal documentation to support this use. Because it has an estrogenic effect, it is not recommended for breast cancer patients. Some women may use saw palmetto to treat thinning hair or hair loss, however this has not been studied. In women, saw palmetto may interfere with the therapeutic effects of oral and patch contraceptives and other hormone-replacement therapies.
J Steroid Biochem 1984;20:515
JAMA, 280(18):1604-9 1998 Nov 11