Quercetin for Allergic Rhinitis
Verdict: Published with Warning
Across 7 PubMed studies, the evidence for Quercetin in Allergic Rhinitis grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.63
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
75%
Broadly consistent
Evidence level
E2
Multiple high-quality MAs (≥2 independent, consistent)
▸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 = 0.625
- 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 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (7)L2 · primary research & systematic reviews
Effect of enzymatically modified isoquercitrin, a flavonoid, on symptoms of Japanese cedar pollinosis
Finding: Total ocular score and ocular itching significantly lower in EMIQ group (p < 0.05); nasal symptoms and serum IgE/cytokines (IL-4, IL-5, IL-13) not significantly reduced.
View on PubMed Preventative effect of a flavonoid, enzymatically modified isoquercitrin on ocular symptoms of Japanese cedar pollinosis
Finding: Ocular symptom + medication score and ocular congestion significantly lower weeks 5-6 (p < 0.05); nasal symptoms and IgE not significantly different between groups.
View on PubMed Synergic Efficacy of a Multicomponent Nutraceutical Add-On Therapy in Seasonal Allergic Rhinitis in Children
Finding: Significant improvement in nFeNO and eFeNO vs control (p < 0.001) and reduction in nasal eosinophils (p < 0.001) over 12 weeks; multicomponent formula confounds quercetin attribution.
View on PubMed Effects of repeated oral intake of a quercetin-containing supplement on allergic reaction: a randomized, placebo-controlled, double-blind parallel-group study
Finding: Significantly improved JRQLQ scores vs placebo at 4 weeks across multiple symptom domains; specific p-values and effect sizes not reported in abstract.
View on PubMed A multicomponent food supplement with quercetin Phytosome®, zinc and vitamin C may be favorable in managing children with seasonal allergic rhinitis: a pilot study
Finding: Pilot study; no abstract available on PubMed — insufficient data for detailed extraction.
View on PubMed The Efficacy of Quercetin in Attenuating Oxidative Stress and Clinical Symptoms in Allergic Rhinitis: A Systematic Review
— See PubMed for details
View on PubMed Quercetin exhibits multi-target anti-allergic effects in animal models: a systematic review and meta-analysis of preclinical studies
Finding: Pooled preclinical SMD: IgE = −4.28 (95% CI −6.07 to −2.48); eosinophils = −4.22; IL-4 = −4.80; large effect sizes in animal models but no human clinical evidence pooled.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
FDA has no questions; some uses may require a color additive listing source↗
L4b EU EFSA
Against
L4d TW TFDA / 衛福部
Neutral
洋蔥萃取物原料係由洋蔥(Allium cepa)之鱗莖，經萃取製得。前點製得之洋蔥萃取物原料，其每日食用限量，以槲皮素(quercetin)計為1000毫克。 source↗
L5a NIH Office of Dietary Supplements
Cautious
L5c Cleveland Clinic
Neutral
L5e Specialty Society (condition-mapped)
Not addressed