Feng L., Cheah I.K.-M., Ng M., Li J., Chan S.M., Lim S.L. et al. Investigating the efficacy of ergothioneine to delay cognitive decline in mild cognitively impaired subjects: A pilot study. 2024 (NCT03641404; Europe PMC med/39544014).
Rationale
Ergothioneine is a sulfur-containing amino acid that humans obtain almost exclusively from mushrooms; blood levels decline with age and are reduced in neurodegenerative conditions. A Singapore team asked whether long-term ergothioneine supplementation affects biomarkers and cognitive measures in older adults with mild cognitive impairment (MCI).
Methods
A randomized double-blind placebo-controlled pilot study (NCT03641404): 19 participants with MCI took pure L-ergothioneine 25 mg three times weekly or placebo for one year — an unusually long horizon for the field. Blood ergothioneine, oxidative-stress markers and cognitive assessments were tracked.
Results
Supplementation raised plasma ergothioneine levels; no safety signals emerged over the year. Cognitive outcomes in this small pilot are hypothesis-generating rather than definitive — the abstract reports biomarker and safety data more clearly than cognitive endpoints.
Conclusions
The work supports ergothioneine's safety and bioavailability over a year of intake in MCI patients and supplies pilot data for a full-scale trial. It does not establish clinical efficacy — the sample is too small.
Worth noting
Ergothioneine is the "mushroom antioxidant" whose mechanistic case is unusually strong (a dedicated human transporter, OCTN1) — yet clinical proof of cognitive benefit remains ahead. The pilot design (n=19) cannot resolve clinical endpoints; its value is safety plus feasibility for the larger trials now running.