there's human trials

cognitive improvement
https://www.ls-corporation.co.jp/wp-content/uploads/2022/10/ergothioneine_congitive.pdf

and over 1 year, with people aged > 60
https://www.medrxiv.org/content/10.1101/2024.07.08.24310085v1.full.pdf

f92ec67d-100b-4fa5-a512-86ba1002478b-image.png
at 6 months, and still gaining at 12 months

. Following ET intake, an increase in Z-scores was observed in RAVLT assessments (immediate and delayed recalls), which evaluates learning ability and memory (Figure 4a&b). In contrast, no significant increase was observed in Z-scores across all NCA components, in the subjects given the placebo.
Block design scores, which assess visual-motor coordination and problem-solving skills, declined over time in both ET and placebo groups (Figure 4g). Although not measured at baseline, Z-scores of SDMT (written format) in the ET group showed a trend to increase from visit 7 to visit 14 (Figure 4i)

(at 4 weeks visit 1 ergo group also had a better lymphocyte-neutrophil ratio)
dec0b3e9-1154-4776-acb4-5b5f54bd831c-image.png