Reishi for Immune Function
Reishi (Ganoderma lucidum) has only weak, low-quality human evidence for immune function. A few small trials nudge laboratory immune markers, but no study shows it actually reduces infections or improves any real-world health outcome.
Why this grade7-layer evidence engine
This claim earns a C (Weak Evidence) grade because the entire human case rests on just three moderate-quality studies, all measuring surrogate lab markers rather than whether anyone actually got sick less often. Two double-blind RCTs of reishi beta-glucan, one in healthy adults (PMID 36766186) and one in children (PMID 30317947), reported higher CD3/CD4/CD8 T-cell counts, NK activity and IgA versus placebo, but neither disclosed doses or sample sizes, and neither tracked infection rates or clinical endpoints.
The only synthesis evidence, a Cochrane systematic review (PMID 27045603, n=373), studied cancer patients rather than healthy people, so it cannot be generalized to everyday immune support. It found only modest marker shifts (CD3 up 3.91 percent, CD4 up 3.05 percent, CD8 up 2.02 percent) and explicitly judged the evidence insufficient for first-line use, with unsatisfactory methodological quality.
Regulators and clinics reinforce the caution. The US FDA has no questions only about one specific beta-glucan ingredient, not reishi's health effects, and the EU's EFSA has left botanical claims like reishi's on hold, neither authorized nor rejected. The NIH/NCI notes there are no studies of G. lucidum with measured cancer outcomes, and Mayo Clinic, Cleveland Clinic, Harvard Health, the UK NHS, WHO and the CDC offer no endorsement for immune use.
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 = 0.605
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- 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