β‐sitosterol for the treatment of benign prostatic hyperplasia:

Objectives To conduct a systematic review of the evidence for the efficacy of β ‐ sitosterolin men with symptomatic benign prostatic hyperplasia (BPH). Methods Studies were identified through Medline ™ (1966–98), EMBASE ™  , Phytodok, the Cochrane Library, bibliographies of identified trials and review articles, and contact with study authors and pharmaceutical companies. Randomized trials were included if: men had symptomatic BPH; plant extract preparations contained β ‐ sitosterols; a control group received placebo or a pharmacological therapy; and treatment duration was ≥30 days. Study characteristics, demographic information, enrolment criteria and outcomes were extracted. Results Four trials comprising a total of 519 men met the inclusion criteria. All were double‐blind and lasted 4–26 weeks. Three studies used nonglucosidic β ‐ sitosterols and one used a preparation that contained only β‐sitosterol‐β‐d‐glucoside. Compared with placebo, β ‐ sitosterolimproved urinary symptom scores and flow measures. For the two studies reporting the International Prostate Symptom Score (IPSS), the weighted mean difference (WMD) against placebo was −4.9 IPSS points (95% confidence interval, CI,−6.3 to−3.5). The WMD for peak urinary flow rate was 3.91 mL/s (95% CI 0.91 to 6.90, four studies) and for residual volume the WMD was −28.62 mL (95% CI−41.42 to−15.83, four studies). β ‐ sitosteroldid not reduce prostate size. The trial using pure β‐sitosterol‐β‐d‐glucoside (WA184) showed no improvement in urinary flow measures. Withdrawal rates for men assigned to β ‐ sitosterol and placebo were 7.8% and 8.0% (not significant), respectively. Conclusion β‐sitosterolimproves urological symptoms and flow measures. However, the existing studies are limited by short treatment duration and lack of standardized β ‐ sitosterol preparations. Their long‐term effectiveness, safety and ability to prevent the complications of BPH are unknown.