Saitsu Y., Nishide A., Kikushima K., Shimizu K., Ohnuki K. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomedical Research (Tokyo). 2019;40(4):125–131.
Rationale
Following positive preclinical data on hericenones and erinacines and the earlier Mori 2009 trial in MCI patients, the question remained whether the mushroom does anything for people without diagnosed impairment. This work tested 12 weeks of fruiting-body capsules in healthy middle-aged and older adults.
Methods
A randomized double-blind placebo-controlled parallel-group trial: 31 healthy volunteers aged 50–80 received 4 capsules/day containing H. erinaceus fruiting body (≈3.2 g/day) or placebo for 12 weeks, with cognitive testing at baseline, 8 and 12 weeks.
Results
Of three cognitive tests administered, only the MMSE showed significant improvement in the H. erinaceus group versus placebo; Benton visual retention and the S-PA test did not reach significance.
Conclusions
Twelve weeks of H. erinaceus improved a global cognitive screen (MMSE) versus placebo in healthy adults 50+ — consistent with the hypothesis of a preventive effect on age-related cognitive decline, but the narrow pattern of significance limits the conclusion.
Worth noting
The honest reading: one of three tests moved. MMSE is a coarse screening instrument, not a sensitive memory measure; the more specific tests (Benton visual retention, S-PA) did not confirm a broad effect. n=31 across two arms detects only substantial effects. Taken together with Mori 2009 (MCI population), the consistent direction is encouraging, but each individual study is small.