Garlic for Cholesterol
Despite popular marketing, the best evidence indicates that garlic supplements do not meaningfully lower cholesterol. Several meta-analyses report a small pooled reduction, but the most rigorous single trial and major clinical bodies find no reliable benefit, so garlic should not replace proven cholesterol therapies.
Why this grade7-layer evidence engine
At first glance the pooled data look favorable. Meta-analyses report small reductions in total cholesterol: about 10 mg/dL across 108 trials in a 2026 review (PMID 40580481), 0.64 mmol/L in a 2024 analysis (PMID 39113105), and larger effects in older pooled work (PMID 29718835; PMID 23590705, which found benefit only after more than two months of use). The grade is held down because these analyses mix heterogeneous preparations with inconsistent allicin doses, and many included trials are short and small.
The decisive problem is that the single most rigorous trial contradicts the pooled signal. Gardner's NIH-funded, double-blind, 6-month RCT (PMID 17325296, n=192) tested raw garlic, powdered supplement, and aged extract head-to-head and found none lowered LDL or total cholesterol versus placebo. When the best-controlled study shows nothing, a pooled average built on weaker trials cannot carry a positive verdict.
Clinical and regulatory consensus aligns with that null result. Mayo Clinic states recent research shows no cholesterol-lowering benefit, and Cleveland Clinic, Harvard Health, and the mapped specialty society all advise against garlic for this purpose. The US FDA formally refused to authorize a garlic-cholesterol health claim, and EFSA has not authorized cardiovascular claims; the WHO monograph lists only adjuvant use. Note too that garlic can interact with warfarin and antiplatelet drugs, raising bleeding risk.
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 = 0.385
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (4 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