Authoritative summary Evidence context Summary of multiple laboratory and human studies
NCI medicinal mushroom evidence summary
NCI reviews human and laboratory research on several medicinal mushrooms. The clearest human evidence discussed is for PSK, a specific Turkey Tail-derived product used with standard cancer treatment in Japan. This is not evidence that ordinary retail mushroom supplements treat cancer.
- What was studied
- Multiple mushroom products, including the specific Turkey Tail extract PSK and various Reishi preparations
- Setting
- Mixed treatment settings
- Why it ranks here
- This is an authoritative evidence map, not a single clinical experiment or a treatment endorsement.
Limits and cautions
- The summary covers different mushroom species and preparations that are not interchangeable.
- Many findings concern immune markers or laboratory models rather than survival or quality of life.
- A summary cannot replace review of the individual trial methods and risk of bias.
The FDA has not approved medicinal mushrooms as a treatment for cancer or another medical condition in the United States.
Randomized trial Early signal 48 healthy Japanese adults aged 60 to 85 were randomized; 47 completed (placebo 14, Y10M 16, C5304 17)
Two Maitake strains produced different cognitive results in a small randomized trial
Forty-eight healthy older adults were randomized and 47 completed an 18-week trial. Y10M differed from placebo on adjusted post-intervention MoCA-J score (p=0.045) and MoCA-J change (p=0.040); C5304 did not. Neither strain differed from placebo on MMSE or HDS-R. No participant discontinued because of an adverse effect. This small, manufacturer-funded study does not establish dementia prevention or a general Maitake effect.
- What was studied
- Bread containing 50 g per day of fresh Maitake strain Y10M or C5304, compared with Maitake-free placebo bread, for 18 weeks
- Setting
- Studied alone
- Why it ranks here
- Randomization and active strain comparison strengthen the design, while the small groups, multiple cognitive outcomes, and a result seen for only one strain make replication essential.
Limits and cautions
- The three completion groups were small (14, 16, and 17), efficacy used a per-protocol analysis, and multiple cognitive, immune, and laboratory outcomes leave a meaningful risk of chance findings.
- The favorable cognitive result was strain-specific: C5304 did not differ from placebo on MoCA-J.
- Reported mean MoCA-J scores fell in the placebo group (26.9 to 25.9) while rising in the Y10M group (26.2 to 27.3), so the between-group difference reflects both changes, not improvement in the Y10M group alone. The paper's p-values come from baseline-adjusted ANCOVA models.
- Participants were healthy older Japanese adults; the trial did not enroll people with dementia or show prevention of cognitive decline.
- YUKIGUNI FACTORY funded the study, manufactured the Maitake test foods, and employed two authors; the paper states that the sponsor did not influence data collection or analysis.
- The study population was geographically restricted, diets were not controlled, genetic and other lifestyle factors were not analyzed, immune assessment was limited to natural-killer cells, and the authors could not explain the strain difference.
Maitake products are not FDA-approved to prevent or treat cognitive impairment, dementia, or another medical condition.