Omega-3 / Fish Oil for Arthritis
Omega-3 (fish oil) earns preliminary-evidence support for arthritis: multiple meta-analyses show it modestly eases joint pain and morning stiffness, particularly in rheumatoid arthritis, but it is an add-on to standard care, not a cure, and objective inflammation markers often do not improve.
Why this grade7-layer evidence engine
The grade reflects consistent but moderate evidence. A 2025 systematic review of 41 RCTs (PMID 41267881) found omega-3 significantly reduced pain in rheumatoid arthritis (SMD -0.42; overall pooled SMD -0.55), and a 2024 meta-analysis (PMID 38922552) showed fewer tender joints (SMD -0.59). A 12-week double-blind RCT (PMID 26925896) cut morning stiffness from 128 to 40 minutes and let 72% of patients reduce painkillers.
Two factors hold it at preliminary rather than strong. In PMID 38922552 the objective inflammation markers ESR, CRP and DAS28 did not change significantly, so the benefit is mainly symptomatic. Osteoarthritis evidence is weaker: the OA meta-analysis (PMID 37226250) found only a small pain reduction (SMD -0.29), and the rheumatoid-arthritis pooling carried high heterogeneity.
Regulators (FDA, EFSA, NHS, WHO) confirm omega-3 is safe at typical doses but speak to heart and dietary roles, not arthritis. Clinics split: the Arthritis Foundation and Mayo are supportive, while Harvard and Cleveland Clinic call supplement evidence limited and the effect mild. High doses raise bleeding risk with blood thinners.
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 = 0.618
- 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 + 2 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status