Phytosterols for Benign Prostatic Hyperplasia
Beta-sitosterol (the prostate-relevant phytosterol) modestly improves urinary symptoms and flow in men with benign prostatic hyperplasia, but the trial base is small, dated, and limited, so it rates only as weak evidence and should be viewed as an unproven adjunct rather than a substitute for standard medical care.
Why this grade7-layer evidence engine
The signal is consistent but thin. A 2000 Cochrane review (PMID 10796740) pooled four placebo-controlled double-blind trials in 519 men and found beta-sitosterol improved symptom scores (IPSS roughly 4.9 points), peak urine flow (+3.9 mL/s) and residual urine volume, with dropout rates matching placebo. The two largest trials agree: Berges 1995 (PMID 7540705, n=200) and the German BPH-Phyto study by Klippel 1997 (PMID 9313662, n=177, IPSS improvement 5.4 points, P<0.01), and an 18-month follow-up cohort (PMID 10792163) suggested the benefit holds with continued use.
Three weaknesses cap the grade at C. No trial shrank the prostate, so the effect is purely symptomatic; the studies are old (1995-2000), short (mostly 26 weeks or less), and dominated by heterogeneous German Harzol preparations with undisclosed funding, leaving long-term safety and industry-bias questions open. The benefit is also smaller than that of alpha-blockers or 5-alpha-reductase inhibitors.
Regulators and specialists do not back this use. The FDA and EFSA authorize phytosterols only for cholesterol-lowering, and UK NICE advises against them even for heart disease; the WHO/JECFA statement is a safety intake limit, not an efficacy endorsement. The American Urological Association classes plant therapies as not recommended for BPH given insufficient evidence, and Cleveland Clinic, Harvard and Mayo offer no supportive endorsement, which is why it ships published with a warning.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.523
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status