Astragalus for Immune Function
Astragalus can shift blood immune markers such as the CD4/CD8 ratio in human trials, but these are surrogate measures, and there is no reliable evidence it lowers infections or improves clinical outcomes in healthy people.
Why this grade7-layer evidence engine
Two human meta-analyses lean favorable. A 2023 systematic review (PMID 37952511, n=1094) found lower proinflammatory cytokines and a higher CD3 count and CD4/CD8 ratio (p<0.0001), and a 2025 meta-analysis of 31 RCTs (PMID 40208321, n=2648) found astragalus polysaccharides raised CD3+, CD4+, and the CD4/CD8 ratio (p<0.01), with CD8+ unchanged. An older pilot RCT (PMID 17661330) noted more T-cell activation but reported no p-values.
The grade stays Weak (C) because every result is a surrogate immune marker, not a clinical endpoint such as infection rate or illness duration. Heterogeneity is high, doses and routes were not standardized (some injectable), and the 2025 data come mostly from cancer patients on adjuvant care, so they do not extrapolate cleanly to general immune support in healthy adults.
No major Western authority endorses this use. The FDA lists only tragacanth gum (Astragalus spp.) as a food additive, not an approved immune claim, while EFSA, NHS, WHO, NIH ODS, Mayo Clinic, Cleveland Clinic, and Harvard Health offered no supporting position. A drug-interaction flag with immunosuppressants and heavy affiliate marketing add further reason for caution.
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 = 0.58
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
- tier_strict_requirement_check — | B→C 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status