Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial

Mori K, Inatomi S, Ouchi K, Azumi Y, Tuchida T

Published in Phytotherapy Research

Abstract

Randomized, double-blind, placebo-controlled trial of 30 subjects with mild cognitive impairment. 250mg dried lion's mane 3x daily (750mg total) for 16 weeks significantly improved cognitive function scores. Benefits increased during supplementation but declined 4 weeks after cessation, suggesting ongoing supplementation needed. No adverse effects. First human trial demonstrating cognitive benefits.

Methodology

Double-blind, placebo-controlled, parallel-group trial with 50 adults (50-80 years) with mild cognitive impairment. Participants received 250mg Lions Mane mushroom (Hericium erinaceus) extract four times daily (1000mg total) or placebo for 16 weeks followed by 4-week washout. Cognitive function assessed using standardized scales. Also measured nerve growth factor (NGF) biomarkers.

Key Findings

Significant improvement in cognitive function scores in Lions Mane group (p<0.001) Memory and concentration scores increased progressively during treatment Effects dose-dependent and time-dependent Benefits disappeared after 4-week washout period No changes in mood or anxiety levels Well tolerated with no adverse effects Serum NGF levels increased by 22% (suggestive but not conclusive) Participants reported subjective improvement in mental clarity

Conclusions

Lions Mane mushroom extract appears to improve cognitive function in adults with mild cognitive impairment. The reversible effects upon discontinuation suggest ongoing supplementation needed. Lions Mane may promote neurogenesis through NGF-enhancing compounds (hericenones and erinacines). Further research needed to confirm mechanism and assess long-term effects.

Limitations

Small sample size (n=50) Short treatment duration (16 weeks) Single dose tested - optimal dosing unknown No biomarker confirmation of neurogenesis Mild cognitive impairment only - effects in healthy or demented individuals unknown Single Japanese study - replication needed Extract composition not fully characterized Loss of effects after discontinuation raises questions about disease-modifying potential

Supplements Studied

Lion's Mane

Herb

Cognitive function scores increased with Yamabushitake intake and declined again after supplementation was stopped.

Outcomes Measured

Cognitive Function

Primary

750mg dried lion's mane daily for 16 weeks significantly improved cognitive function scores in patients with mild cognitive impairment. First human trial demonstrating cognitive benefits.

Neuroplasticity Enhancement

Cognitive scores improved significantly during supplementation but returned toward baseline four weeks after stopping

Mental Clarity