Q-At the age of 48, I am beginning to have symptoms of prostate enlargement, such as difficulty urinating. I have seen a number of expensive herbal and vitamin supplements, such as zinc, evening primrose oil and saw palmetto, which claim to help this condition. But before spending a fortune on these supplements, can you confirm whether any of these are really effective? RG, Cusop, Herefordshire......
A-Current estimates tell us that prostate enlargement or benign prostatic hyperplasia (BPH) affects over 50 per cent of men in their lifetime. Its frequency rate increases with advanced age from approximately 5-10 per cent at age 30 to over 90 per cent in men over 85 years of age (Prostate, 1996; 6 [Suppl]: 67-73).
The prostate lies just below the base of the bladder and surrounds the urethra. When it becomes enlarged, it blocks the flow of urine, causing a range of problems, including pain, frequent urination, nighttime awakenings and other urinary difficulties. If left untreated, BPH can eventually lead to kidney damage, so effective treatment is important.
Conventional drugs such as finasteride (Proscar) have a poor record in treating BPH. Indeed, a review of the studies of all drugs on offer including alpha blockers and cholesterol lowering agents found "no convincing evidence" that the currently available medical treatment for BPH is any more effective than a placebo (Urol Res, 1997; 252: 107-14).
In contrast, alternative medicine offers a number of treatments with good evidence of success. However, there are a few provisos. According to Michael Murray, author of Natural Alternatives to Over the Counter and Prescription Drugs (Quill, 1994), the chances of success with any alternative treatment for BPH appears to be determined by the degree of obstruction, indicated by the residual urine levels.
For levels less than 50 mL, the results are usually excellent. For levels of 50-100 mL, the results are usually good but, with levels of 100-150 mL, it will be harder to produce significant improvement in the customary four to six weeks of treatment. If your residual urine level is more than 150 mL, botanical medicines are not likely to produce significant results.
Relief from BPH is also more likely if the supplement you take has the correct amount of the active ingredient. Many products on the market contain suboptimal doses of the herbs and nutrients that have proven useful.
Perhaps the most well tested and successful herbal is saw palmetto (Sere-noa repens or Sabal serrulata) berry extract. This has been used for more than 75 years to treat BPH (Rozhl Chir, 1993; 72: 75-9) and several studies attest to its effectiveness (Intern Urol Nephrol, 1996; 28: 767-72; Curr Ther Res, 1994; 55: 776-85).
There have been studies comparing a proprietary form of saw palmetto (Permixon) with finasteride. In one randomised international study of more than 1000 patients, both treatments relieved BPH in two thirds of cases, but Permixon produced far fewer problems in sexual function, decreased libido and impotence (Prostate, 1996; 29: 231-40). What's more, while finasteride typically takes up to a year to produce significant benefit, saw palmetto produces better results in a much shorter period of time. Most patients achieve some relief of symptoms within the first 30 days of treatment.
To benefit from saw palmetto, it is essential that the supplement you take is standardised to contain 85-95 per cent fatty acids and sterols, and be used at the recommended dosage of 160 mg twice daily.
Extracts of the bark of Pygeum africa num, an African evergreen, have also proved effective. In one German study, the herb proved twice as effective as placebo, improving urinary symptoms in two thirds of men (Wien Klin Wochenschr, 1990; 102: 667-73).
Although effective, P. africanum is not as potent as saw palmetto and can produce unpleasant gastrointestinal symptoms (Br J Clin Pharmacol, 1984; 18: 461-2; Med Praxis, 1983; 4: 143-8).
Beta sitosterol is the main active ingredient in the bark of P. africanum, and studies have confirmed its effectiveness in the treatment of BPH (J Ann Urol, 1984; 18: 193-5; Progr Med, 1986; 42: 165-9; Min Urol Nefrol, 1987; 39: 45-50). In a German study of 200 men with BPH, researchers found that 60 mg/day of beta sitosterol was effective (Lancet, 1995; 345: 1529-32). After three months, the men taking beta sitosterol extract showed statistically significant improvement in urine flow velocity; those taking the placebo did not. Another interesting finding was that beta sitosterol lowered blood cholesterol. High cholesterol is thought to be an important factor in stimulating prostate growth.
The optimal dose of P. africanum is 50-100 mg twice daily of an extract containing 14 per cent beta sitosterol and 0.5 per cent N-docosanol (another active ingredient).
Another effective treatment is stinging nettles (Urtica dioica). Several studies have shown definite decreases in frequency of urination and in residual urine levels with this herb (Clin Ther, 1993; 15: 1101-20; Planta Med, 2000; 66: 44-7; Planta Med, 1997; 63: 307-10). In one of these studies, nighttime urination frequency decreased by half (ZFA [Stuttgart], 1979; 55: 1947-50).
An increased concentration of the male hormone dihydrotestosterone (DHT) is thought to be one cause of BPH. DHT is responsible for the over production of prostate cells which, in turn, enlarge the prostate. Nettles are believed to affect the way DHT binds to hormone receptors in the prostate and may be one reason why it helps the treatment of BHP (Fortschr Med, 1983; 101: 713-6).
Standardised extract of flower pollen (optimally, two 500-mg tablets daily) have demonstrated their effectiveness in treating BPH for over 35 years in Sweden (look for the proprietary product Cernilton, produced by A.B. Cernelle in Sweden).
According to WDDTY panellist Harald Gaier, pollen is the plant equivalent of the male fertilising element, and its beneficial effect is probably due to plant hormones. Five successful studies have been reported (Br J Urol, 1990; 66: 398-404).
Combinations of herbs are sometimes the most effective approach. Nettles may be successfully combined with P. africanum, and have also proven useful combined with saw palmetto. In a double blind study comparing this herbal combination with finasteride, similar improvements were produced by the drug and the herbs although, again, the herbs produced far fewer side effects than the drug, particularly with regard to diminished ejaculation, erectile dysfunction and headache (Urol Ausg A, 1997; 36: 327-33).
There is also evidence that men with BPH benefit from nutritional supplements. Nutritionists believe that prostate problems can stem from low levels of zinc and the essential fatty acids omega-3 and omega-6, as well as amino acid deficiencies.
Zinc levels are higher in the prostate than anywhere else in the male body because high levels are required to metabolise male hormones. When the prostate is enlarged, zinc doesn't bind as well to the prostate cells. For BPH, 30-45 mg of zinc daily is considered a therapeutic dose.
A combination of the amino acids l-glutamic acid, l-alanine and glycine (two 360-mg capsules three times daily for two weeks and one capsule daily thereafter) has also been shown to shrink the prostate and improve symptoms (Am J Geriatr, 1962; 10: 426-30; Hinyokika Kiyo, 1970; 16: 231-6). The effect is enhanced when combined with P. africanum (Arch Esp Urol, 1988; 41: 495-9).
EFAs are the nutritional precursors of prostaglandins that, in turn, inhibit testosterone from binding to the prostate (Prostate, 1983; 4: 247-51). Supplementing with 1000 mg of evening primrose oil daily is one way to boost levels of EFAs. Another is to take pumpkinseed oil, a powerful antioxidant (Pharmacol Res, 2000; 41: 555-63; Pharmacol Res, 1997; 35: 403- 8), which is sometimes included in prostate remedies.
Whether or not supplements are the most effective way to reduce problems that have already appeared is unclear. However, doctors such as WDDTY panellist Leo Galland believe that supplementation is vital to prevent prostate enlargement from occurring in the first place.