Elderberry for Common Cold
Elderberry does not appear to prevent colds, and while a few small trials hint it might shorten symptoms in people already sick, the evidence is weak, inconsistent, and clouded by industry funding. There is no reliable proof it works.
Why this grade7-layer evidence engine
The grade is weak because the entire literature is just a handful of small, conflicting trials. The most-cited positive result, a 312-person air-traveller RCT (PMID 27023596), found no reduction in how often people caught colds; its only benefit, shorter and milder colds, came from just 29 sick participants and was funded by a Sambucol manufacturer. A meta-analysis pooling four weak trials in 180 people (PMID 30670267) reported a large effect on symptom duration but blended cold and influenza outcomes.
Crucially, the best independent test undercuts the positive signal. A non-industry-funded emergency-room RCT (PMID 32929634) found elderberry no better than placebo, and a 2021 NIH-funded systematic review (PMID 33827515) concluded it likely does not prevent colds and that any duration benefit is uncertain. All benefits rest on self-reported symptom scores, not lab-confirmed infection.
Authoritative bodies are split to skeptical. The Cleveland Clinic sees no reason to take it, while Mayo Clinic notes only that some research suggests a roughly two-day shortening and says more research is needed. The FDA treats elderberry as a food flavoring, not a cold treatment, and the WHO notes there are no controlled clinical data. Raw or unripe elderberry is also unsafe unless properly heat-processed.
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 = 0.412
- 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 1 個 hard + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status