Saw palmetto is a leading treatment for benign prostatic hyperplasia (BPH) in Germany and Austria, and is among the top five dietary supplements sold in the United States. It relieves bladder and urinary disturbances associated with stage I and II BPH. Stage I symptoms include frequent urination, nocturia, delayed urination, low urinary force, and post-void dribbling; stage II symptoms herald bladder function debility and include urgency and incomplete emptying of the bladder. Sexual dysfunction has also been reported. The majority of men over 60 are considered to have urinary symptoms attributable to BPH. The condition may progress to prostate cancer, bladder infections, and damaged kidneys if left untreated.

First used in the treatment of BPH late in the nineteenth century, saw palmetto has been the subject of at least 20 laboratory studies and 18 clinical studies. These experiments demonstrated saw palmetto's antiestrogenic and antiandrogenic effects and confirmed that the berry extract reduces 5-alpha-reductase. These are considered significant interventions in the treatment of BPH.

Most recently, researchers assessed the results of 18 controlled trials and concluded that saw palmetto can be as effective as finasteride in improving BPH-affected urine flow and urgency. Compared to placebo, saw palmetto relieved nocturia by 25%, urinary tract symptoms by 28%, increased peak urine flow by 28%, and decreased residual volume by 43%. Finasteride does shrink the prostate, however, and saw palmetto does not.

Saw palmetto berries provided food and medicine for Native Americans for centuries. Aside from their nutritional value, the berries were considered expectorant, sedative, and diuretic by traditional folk healers. It was used to reduce inflammation in genitourinary catarrh and to treat breast disorders in women. Some herbalists claim that saw palmetto can increase breast size, and that it is an aphrodisiac. These claims are unsubstantiated, however.

From 1906 to 1916, saw palmetto berries were listed in the U.S. Pharmacopoeia and were described as effective remedies for chronic and subacute cystitis, chronic bronchitis, laryngitis, catarrh that accompanies asthma, and enlarged prostate glands. It was also in the National Formulary from 1926 to 1950.

The saw palmetto shrub is a fan palm that grows from 6 to 10 feet in warm climates, from South Carolina to Mississippi and throughout Florida. Lush palmate leaves have lance-shaped leaflets and are supported by spiny stems. Flowers are white and develop yellow olive-like berries, which become bluish-black when ripe and have an oily sheen attributable to their fatty acid content.

• Berries

Saturated and unsaturated, mostly free fatty acids (capric, caprylic, caproic, lauric, palmitic, and oleic acids); free and conjugated sterols; fruits also contain high-molecular weight polysaccharides and flavonoids. Fat-soluble extracts are standardized to contain 85% to 95% fatty acids and sterols.

Crude dried berries, tea, powdered encapsulations, tablets, tinctures, and liposterolic extracts standardized to contain 85% to 95% fatty acids and sterols.

Saw palmetto was historically used as an expectorant and to treat general debility, respiratory catarrh, and muscle wasting due to age or menopause.

Traditional herbal actions: Tonic for both female and male reproductive systems and urinary tracts, nourishing tonic, anti-inflammatory, urinary antiseptic, relaxant, diuretic.

Clinical applications: Used for the relief of symptoms of stage I and II BPH. Future research may lead to the treatment of female androgen excess disorders, such as hirsutism and polycystic ovary disease. Increases milk flow in nursing mothers, used to treat infections of the genitourinary system, such as cystitis, urethritis, and salpingitis.

Liposterolic extracts act at the cytosolic, androgenic receptor of prostate tissue in vitro to inhibit 5-alpha-reductase, block adrenergic receptors, and inhibit DHT-producing enzymes. Inhibition of dihydrotestosterone (DHT) and 5-alpha-reductase may have a positive effect in the treatment of BPH. Finasteride inhibits 5-alpha-reductase, which in turn blocks testosterone from transforming into DHT, and DHT may be responsible for the hyperproliferation of prostate cells involved in the etiology of BPH.

Despite evidence of estrogenic activity, liposterolic extracts also significantly stimulate antiestrogenic effects; it blocked nuclear estrogen receptors in prostatic tissue samples of patients with BPH. After a 90-day treatment period, researchers analyzed the function of androgen, estrogen, and progesterone receptor tissues in 35 study participants. The group given saw palmetto extract had lower cellular and nuclear estrogen and progesterone receptor values than the placebo group. Cellular androgen levels remained the same, but nuclear androgen levels declined. Estrogen may promote BPH due to inhibition of hydroxylation and elimination of DHT. Some investigators feel that estrogen's role in BPH is more significant than that of DHT.

To reduce symptoms associated with stages I and II BPH: 160 mg liposterolic extract, standardized to contain 85% to 95% fatty acids and sterols, or equivalent, bid.

• Tincture (1:4): 2 to 4 ml tid
• Fluid extract of dried berry pulp (1:1): 1 to 2 ml tid
• Capsules: 1,000 mg tid
• Tea: 2 tsp. dried berry with 24 oz. water, simmer slowly until liquid is reduced by half, take 4 oz. tid. The tea tastes vile but is effective.

Adverse effects are very rare and include mild stomach upset. The American Herbal Products Association gives saw palmetto a class 1 safety rating, indicating that it is safe with appropriate use.

Before self-medicating with saw palmetto, patients should get a firm diagnosis of BPH. Although saw palmetto relieves symptoms, it does not shrink the prostate; therefore, the condition should be closely monitored by a health care provider.

Saw palmetto has hormonal effects and should not be used during pregnancy or lactation until specific studies prove otherwise.

No clinically significant interactions between saw palmetto and conventional medications are known to have been reported in the literature to date, including the German Commission E monograph (Blumenthal 1998). Because the mechanism of action for saw palmetto is similar to that for finasteride, it has been recommended that this herb not be used in combination with finasteride or other antiandrogenic drugs (Chavez and Chavez 1998).

Dietary supplement in the U.S., saw palmetto is approved for use in the treatment of stage I and II BPH by Germany's Commission E, and is on the General Sales List (GSL) in England.

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