Bee Propolis for Immune Function
Propolis reliably lowers inflammatory markers like IL-6 and TNF-alpha, but there is no solid proof it actually strengthens immune function or prevents infections, so it earns only a weak (C) grade. Treat any "immune support" claim with caution.
Why this grade7-layer evidence engine
Three 2024-2025 meta-analyses of randomized trials (PMID 40421039, n=2,212; PMID 39127756; PMID 39490733, n=1,139) consistently found that propolis supplementation significantly reduces inflammatory cytokines such as IL-6 and TNF-alpha, with CRP also dropping in two of them (it was non-significant overall in PMID 39490733). This is a genuine, consistent biological signal, which is why the grade is not lower than C.
The grade stays at C, however, because every one of those positive results is a surrogate blood-marker, not a real-world immune outcome. No meta-analysis measured infection rates, colds, or vaccine response. The single trial with a hard endpoint (PMID 34311528) was a small, open-label, industry-funded study of Brazilian green propolis in hospitalized COVID-19 patients; it shortened hospital stay by 5-6 days but cannot be generalized to everyday supplements.
Authorities reinforce the caution. The US FDA has issued warning letters treating propolis 'antibacterial, antiviral and antifungal' throat-spray claims as unapproved-drug claims, the EU EFSA rejected propolis immune-health claims because the substance is poorly characterized and no cause-and-effect was established, and Cleveland Clinic, the only major clinic to address it, takes a negative stance. Propolis composition also varies widely by origin, and bee-allergic people risk serious reactions.
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 = 0.51
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 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