Maitake Mushrooms Show Promise for Cognitive Health in Older Adults
A recent 18-week clinical trial indicates that regularly eating maitake mushrooms may enhance cognitive function in healthy older adults, especially in memory performance.
This study suggests that these mushrooms could potentially slow down the progression from normal cognitive abilities to mild cognitive impairment, which can lead to dementia.
Interestingly, it appears that the immune system, specifically natural killer cell activity, may play a significant role in the cognitive benefits noticed.
Dementia currently impacts millions globally, and as populations age, the need for accessible dietary options to support cognitive health is becoming increasingly urgent. Maitake mushrooms (Grifola frondosa), long utilized in East Asian cuisine, have shown promising evidence in areas like immune functionality, blood pressure management, and gut health. However, their cognitive effects on healthy individuals have remained largely unexplored until now.
Researchers from Yukiguni Factory, a Japanese food producer, collaborated with experts from Kobe Pharmaceutical University and Shimane Rehabilitation College to conduct a randomised, double-blind, placebo-controlled trial involving 47 healthy Japanese participants aged 60 and older. The findings, published in the Journal of Nutritional Science and Vitaminology in 2026, provide the first controlled evidence linking maitake mushroom consumption to improved cognitive function among older adults.
What the Trial Found
Participants were split into three groups. Two of them ingested bread containing 50 grams of maitake mushroom paste, specifically either the Y10M or C5304 strain developed by Yukiguni Factory. The third group received a placebo bread without mushroom content. Researchers monitored blood levels of ergosterol, a lipid people find primarily in fungi, which increased significantly in the groups eating mushrooms when compared to the placebo group.
The main cognitive outcomes were measured using the Montreal Cognitive Assessment (MoCA). After 18 weeks, those consuming the Y10M strain demonstrated a significant improvement in their MoCA scores compared to the placebo group. Notably, the memory subscale, which is quite challenging, also showed a positive shift in this group. Conversely, the C5304 group, which consumed similar amounts of mushroom but did not see improvement, suggests there might be uncharacterized differences in either the minor components or polysaccharide structures of the strains.
No adverse side effects were reported, and key health markers related to blood chemistry and liver function remained normal throughout the trial.
The Immune Connection
One of the most intriguing discoveries was related to the immune system. Natural killer (NK) cells, which circulate in the bloodstream and help remove abnormal proteins from tissues, were notably more active in the Y10M group after 18 weeks. This increased NK cell activity also correlated positively with higher MoCA scores, hinting at a possible link between cognitive improvement and immune response.
This connection is important as research around fungal compounds is revealing the ways mushroom-derived polysaccharides, including beta-glucans, interact with our immune systems beyond traditional associations. In relation to cognition, NK cells might help clear away amyloid-beta, the protein known to accumulate in Alzheimer’s disease, potentially by enhancing the function of microglial cells in the brain. While the maitake polysaccharides in Y10M bread might stimulate this process, the authors caution that the exact mechanism remains to be confirmed.
Limitations and the Road Ahead
The research team acknowledged some limitations, such as the relatively small sample size, unrestricted diets outside the intervention, and the narrow focus on NK cells within a broader immune context. Future larger studies spanning diverse populations, extended timelines, and deeper mechanistic insights will be essential before any dietary recommendations can be responsibly made.
Nonetheless, this research offers an encouraging preliminary insight: incorporating a commonly consumed mushroom into daily diets could significantly help maintain cognitive health in older adults, with an immune-related mechanism warranting further scientific exploration.
