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

Summary & key facts

Researchers ran a small, carefully controlled trial to see if eating the edible mushroom Yamabushitake (Hericium erinaceus) could help people with mild thinking problems. Thirty Japanese adults aged 50 to 80 with mild cognitive impairment were split into two groups of 15. One group took about 3 grams of mushroom powder each day for 16 weeks, the other took a placebo. The mushroom group did better on a standard thinking-and-memory test at 8, 12 and 16 weeks, but the benefit fell within a month after they stopped. Blood tests showed no obvious harm in this study. The findings are promising but come from a small, short study and need confirmation in bigger, longer trials.

Key facts:

• Thirty people aged 50 to 80 with mild cognitive impairment took part. They were split into two groups of 15.
• The treatment group took about 3 grams of Yamabushitake mushroom powder per day for 16 weeks. The other group took a placebo.
• On a standard test that measures thinking and memory, the mushroom group scored higher than the placebo group at weeks 8, 12 and 16.
• The improvement in test scores grew while people kept taking the mushroom, but scores fell significantly within four weeks after they stopped.
• Routine lab tests during the study did not show adverse effects from taking the mushroom.
• Because the trial was small and done only in Japanese adults over 50, the results suggest a possible benefit but need replication in larger and longer studies.

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

Substances

Other

Conditions & symptoms

Difficulty focusing