Saw palmetto extract
Saw palmetto extract is an extract of the fruit of Serenoa repens. It is rich in fatty acids and phytosterols. It has been used in traditional, eclectic, and alternative medicine to treat a variety of conditions, most notably benign prostatic hyperplasia (BPH). Review of clinical trials, including those conducted by the National Center for Complementary and Alternative Medicine, found the extract to be no more effective than placebo for BPH.
Saw palmetto is used in several forms of traditional herbal medicine. American Indians used the fruit for food and to treat a variety of urinary and reproductive system problems. The Mayans drank it as a tonic, and the Seminoles used the berries as an expectorant and antiseptic.
Crude saw palmetto extract was used by European/American medical practitioners for at least 200 years for various conditions, including asthenia (weakness), recovery from major illness, and urogenital problems. The 
King's American Dispensatory (1898) says of the extract:
It is also an expectorant, and controls irritation of mucous tissues. It has proved useful in irritative cough, chronic bronchial coughs, whooping-cough, laryngitis, acute and chronic, acute 
Saw palmetto extract is the most popular herbal treatment for benign prostatic hyperplasia, a common condition in older men. Early research indicated that the extract is well-tolerated and suggested "mild to moderate improvement in urinary symptoms and flow measures." Later trials of higher methodological quality indicated no difference from placebo. Questions of adequate blinding and delivery of any active ingredients remain. The latest Cochrane Database review (2009) concludes that "Serenoa repens was not more effective than placebo for treatment of urinary symptoms consistent with BPH."
A 2011 study published in JAMA (The Journal of the American Medical Association) reported on a double-blind study that eleven North American clinics conducted on 369 men. The study found that saw palmetto fruit extract failed to reduce urinary tract symptoms more than placebo. Men in the experimental group experienced a 2.20 point drop in their American Urological Assn. Symptom Index (AUASI) score. However, men in the placebo group saw a 2.99 point drop. The Los Angeles Times reports, “42.6% of the men in the extract group saw their AUASI scores fall by at least three points; 44.2% of the men in the placebo group saw the same degree of benefit.” The study was funded by several offices within the NIH, including the National Center for Complementary and Alternative Medicine.”
Inhibition of both forms of 5-alpha-reductase with no reduction in cellular capacity to secrete prostate-specific antigen is indicated. Other proposals for mechanisms of action include interfering with dihydrotestosterone binding to the androgen receptor, relaxing smooth muscle tissue similarly to alpha antagonist drugs, and acting as a phytoestrogen.
Limited in vitro and animal model studies have investigated potential for use in the treatment of cancer. However, according to the American Cancer Society, "available scientific studies do not support claims that saw palmetto can prevent or treat prostate cancer in humans".
Few side effects or allergic reactions are associated with saw palmetto extract use. The most common are gastrointestinal, some of which may be reduced by taking the extract with food. Use may increase the risk of bleeding or affect sex hormones, and concurrent use of other drugs with similar action should be avoided.
Beta-sitosterol, a chemical present in saw palmetto extract, is chemically similar to cholesterol. High levels of sitosterol concentrations in blood have correlated with increased severity of heart disease in men who previously suffered heart attacks.
Precautions and contraindications
The use of saw palmetto extract is not recommended in children under 12 years old because it may affect the metabolism of androgen and estrogen hormones. In a case report, an 11 year old girl experienced hot flashes after using saw palmetto extract. The symptom went away after she stopped taking the extract.
Pregnancy and lactation
Saw palmetto extract should not be used during pregnancy. The effects of saw palmetto extract on androgen and estrogen metabolism can potentially impair fetal genital development. Saw palmetto extract should also be avoided during breastfeeding due to a lack of available information.
Saw palmetto extract can significantly slow down blood clotting, leading to increased bleeding time before and after surgery. In a case report, a patient taking saw palmetto had increased bleeding time during surgery. The bleeding time returned to normal after he stopped taking the herb. It is recommended that the use of saw palmetto extract be stopped at least two weeks before a scheduled surgery.
Saw palmetto extract may decrease the effectiveness of estrogen products by reducing estrogen levels in the body via its antiestrogenic effects. It can interfere with the use of birth control pills that contain estrogen as an active ingredient. As a result, it is recommended that an additional form of birth control, such as a condom, be used to prevent pregnancy in patients taking birth control pills with saw palmetto extract. In addition, saw palmetto extract can also interfere with hormone replacement therapy by reducing the effectiveness of estrogen pills. Therefore, the combination of saw palmetto extract with estrogen products should be used with caution.
When used in combination with an anticoagulant or antiplatelet drug, saw palmetto extract can increase the risk of bleeding by enhancing the anticoagulation or antiplatelet effects. Some examples of anticoagulant and antiplatelet drugs include aspirin, clopidogrel, nonsteroidal anti-inflammatory drugs (NSAIDs) and warfarin. Therefore, the combination of saw palmetto extract with anticoagulant or antiplatelet drugs should be used with caution.
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- Felter's complete text
- King's American Dispensatory 1898
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- Saw Palmetto for Prostate Disorders-American Academy of Family Physicians
- Complementary and Alternative Therapies For Cancer Patients Saw Palmetto-University of California at San Diego Medical Center
- Medline Suppletments-Saw Palmetto from National Institutes of Health