Benign prostatic hypertrophy, or BPH, is one of the most common disorders in men over age 60. It affects more than 50 percent of men over age 60 and 90 percent of those in their 70s and 80s, according to the National Institute of Diabetes and Digestive and Kidney Disorders. Symptoms include frequent nocturnal urination, a weak stream while urinating, urgency or dribbling. Prescription medications such as finasteride and herbal supplements such as saw palmetto and stinging nettle are used to treat BPH.
Saw palmetto, finasteride and stinging nettle all have different actions on the prostate. Finasteride, sold only by prescription, blocks the action of 5-alpha-reductase, an enzyme that changes testosterone, the dominant male hormone, to dihydrotestosterone, also called DHT. Saw palmetto blocks the conversion of testosterone to DHT by inhibiting 5-alpha-reductase activity. Saw palmetto also has inhibitory effects on male hormone receptors.
Stinging Nettle Effects
Stinging nettle appears to have different actions; sex hormone binding globulin, or SHBG; aromatase; epidermal growth factor; and prostate steroid membrane receptors may all play a part in reducing BPH symptoms, which does not appear to have 5-alpha-reductase properties, according to a University of Freiburg report published in the August 2007 issue of “Phytomedicine.” Stinging nettle does not reduce the size of the prostate, like the other two drugs, but instead appears to decrease symptoms, possibly by affecting sex hormones or by acting directly on prostate cells. A combination of saw palmetto and stinging nettle is often used as an alternative treatment for BPH.
Finasteride decreases prostate size by 20 to 30 percent in 6 to 24 months, according to Drugs.com. Clinical trials have shown mixed results for the benefit of saw palmetto when treating benign prostatic hyperplasia. According to the German article published by researchers from the University of Freiburg who conducted a review of literature, more confirmatory studies on the effects of stinging nettle are needed to prove its effectiveness
A study conducted by the Urological Sciences Research Foundation in California compared the actions of finasteride and saw palmetto on prostate tissue. The results, reported in the May 2001 of “Urology,” found that both reduced DHT levels, indicating similar actions. The placebo drug had no effect.