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

Summary & key facts

In a small, double-blind, placebo-controlled trial of Japanese adults aged 50–80 with mild cognitive impairment, 30 people were randomly assigned to take Yamabushitake (an edible mushroom) or placebo for 16 weeks. The mushroom group took four 250 mg tablets three times a day and showed higher scores on a cognitive test at weeks 8, 12, and 16; the scores fell after stopping the tablets. Lab tests found no adverse effects, and the authors say the results suggest Yamabushitake may help mild cognitive impairment, but the study was small and the benefit decreased after stopping.

Key facts:

• The study was a double-blind, parallel-group, placebo-controlled randomized trial.
• Thirty subjects were randomized into two equal groups of 15 after a 2-week preliminary exam.
• Participants were Japanese men and women aged 50 to 80 with a diagnosis of mild cognitive impairment.
• The Yamabushitake group took four 250 mg tablets containing 96% Yamabushitake dry powder, three times a day, for 16 weeks.
• Cognitive function was measured using a scale based on the Revised Hasegawa Dementia Scale (HDS-R).
• At weeks 8, 12, and 16, the Yamabushitake group showed significantly higher cognitive scores than the placebo group.
• Scores in the Yamabushitake group increased with longer intake but fell significantly by the fourth week after stopping the 16-week treatment.
• Laboratory tests reported in the study showed no adverse effects from Yamabushitake.

Abstract

A double-blind, parallel-group, placebo-controlled trial was performed on 50- to 80-year-old Japanese men and women diagnosed with mild cognitive impairment in order to examine the efficacy of oral administration of Yamabushitake (Hericium erinaceus), an edible mushroom, for improving cognitive impairment, using a cognitive function scale based on the Revised Hasegawa Dementia Scale (HDS-R). After 2 weeks of preliminary examination, 30 subjects were randomized into two 15-person groups, one of which was given Yamabushitake and the other given a placebo. The subjects of the Yamabushitake group took four 250 mg tablets containing 96% of Yamabushitake dry powder three times a day for 16 weeks. After termination of the intake, the subjects were observed for the next 4 weeks. At weeks 8, 12 and 16 of the trial, the Yamabushitake group showed significantly increased scores on the cognitive function scale compared with the placebo group. The Yamabushitake group's scores increased with the duration of intake, but at week 4 after the termination of the 16 weeks intake, the scores decreased significantly. Laboratory tests showed no adverse effect of Yamabushitake. The results obtained in this study suggest that Yamabushitake is effective in improving mild cognitive impairment.

Topics

Fungal Biology and Applications Ginkgo biloba and Cashew Applications Medicinal Plants and Bioactive Compounds

Categories

Health Sciences Medicine Pharmacology

Tags

Adverse effect Alternative medicine Clinical trial Cognition Cognitive impairment Double blind Hericium erinaceus Internal medicine Medicine Pathology Placebo Placebo group Psychiatry Randomized controlled trial