Ergothioneine for Cognitive Function
Low blood ergothioneine is consistently linked to worse cognition and dementia, but the evidence that taking ergothioneine actually protects or improves cognition rests on a single 19-person pilot trial. It is too early to recommend it for brain health.
Why this grade7-layer evidence engine
The grade is C (weak evidence) because nearly all human data are observational, not interventional. A cross-sectional study of 496 people found dementia patients had the lowest plasma ergothioneine (p<0.001), tracking with hippocampal atrophy, cortical thinning and white-matter lesions (PMID 34673145). A Singapore cohort showed whole-blood levels fall after age 60, with mild-cognitive-impairment elders measuring significantly lower than cognitively normal peers (PMID 27444382). Two reviews echo that lower levels accompany faster cognitive decline (PMID 35090053; PMID 38018890).
The catch is that association is not causation. These designs cannot rule out reverse causation, dementia or its dietary changes may lower ergothioneine, or confounding, where low levels simply mark poor diet (few mushrooms) or worse general health. The only interventional data come from a tiny double-blind pilot RCT in 19 MCI adults taking 25 mg three times weekly for a year, which hinted at better learning and stable neurofilament light, but n=19 is far too small to prove benefit (PMID 39544014).
Authorities reinforce the caution. The FDA recognizes synthetic L-ergothioneine only as GRAS for food safety, with no approved cognitive or disease claim, and EFSA's 2016 opinion likewise addressed only novel-food safety. NHS, WHO, NIH ODS and major clinics (Mayo, Cleveland, Harvard) do not address it for cognition. It appears safe, but its clinical cognitive benefit is unestablished.
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 = 0.575
- 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 級條件未達 (需 E1-E6；實際 E7)
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status