Evidence Hub

The Effect of Ergothioneine Supplementation on Cognitive Function, Memory, and Sleep in Older Adults with Subjective Memory Complaints: A Randomized Placebo-Controlled Trial

I. Zajac, N. Kakoschke, B. Kuhn-Sherlock, Linda S. May-Zhang

Nutraceuticals, 2025

147 participants · 13 citations

Abstract

Ergothioneine is a diet-derived antioxidant with emerging evidence of neuroprotective benefits, but no dose-ranging study has evaluated its effects in healthy older adults. In this 16-week randomized, double-blind, placebo-controlled trial, 147 adults aged 55–79 with subjective memory complaints received ergothioneine (10 mg or 25 mg/day ErgoActive®) or placebo. The primary outcome was the change in composite memory (CNS Vital Signs). Secondary outcomes included other cognitive domains, subjective memory and sleep quality, and blood biomarkers. At baseline, participants showed slightly above-average cognitive function (neurocognitive index median = 105), with plasma ergothioneine levels of median = 1154 nM (interquartile range = 889.9). Plasma ergothioneine increased by ~3- and ~6-fold for 10 mg, and ~6- and ~16-fold for 25 mg, at weeks 4 and 16, respectively (p < 0.001). 25 mg ergothioneine showed a within-group improvement in composite memory at week 4 (p < 0.05), although this was not sustained. Reaction time improved in both groups, dependent on time. Other domains showed null or limited effects. Subjective prospective memory and sleep initiation improved dose-dependently, with significant effects at 25 mg (p < 0.05). Liver function improved and a within-group increase in telomere length was noted. In conclusion, ergothioneine supplementation was safe and well tolerated, with evidence suggesting some benefits in this cohort of healthy older adults. Longer trials in…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 147 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free