Elderberry for Immune Function
Elderberry has not been shown to "boost immunity" or prevent infection; the most it may do is modestly shorten the duration of a cold or flu once you are already sick, and even that benefit is uncertain. It is not a reliable way to strengthen immune function.
Why this grade7-layer evidence engine
No trial has measured a direct immune-function endpoint. Every clinical study tests a symptom surrogate instead. A 2019 meta-analysis of four small RCTs (n=180; PMID 30670267) reported a large reduction in upper-respiratory symptoms, but its funding was undisclosed, so industry conflict of interest cannot be ruled out. A 2021 systematic review of five RCTs (PMID 33827515) found elderberry may shorten cold and flu duration yet does not reduce the chance of catching a cold, and rated the overall evidence as uncertain.
A 2022 systematic review in healthy people (PMID 36364865) found only one eligible elderberry trial: cold duration was about two days shorter (4.75 vs 6.88 days), but the difference in how often people got sick was not statistically significant. The only mechanistic support, increased dendritic-cell maturation and IL-6/TNF-alpha/IFN-gamma (PMID 35409309), comes from a laboratory study and was never linked to any clinical immune outcome.
Regulators and clinicians reinforce the cautious grade. The FDA lists elderberry only as a flavoring/color agent with no authorized immune claim, and the WHO notes there are no controlled clinical data. Mayo Clinic warns elderberry could overstimulate the immune system, a real concern for people with autoimmune disease or on immune-affecting drugs. Small, surrogate-based and inconsistent data, plus no regulatory backing, place this at weak Tier C.
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 = 0.456
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (0 positive vs 1 negative)，由 raw_score 決定
- 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