Maitake Mushrooms Show an Early Signal for Cognitive Health

Key Takeaways

• The randomized, double-blind, placebo-controlled trial included 47 healthy Japanese adults age 60 and older.

• Participants ate bread containing one of two maitake mushroom strains or similar bread without maitake for 18 weeks.

• Only the group given the Y10M maitake strain improved on the Japanese version of the Montreal Cognitive Assessment compared with the placebo group; the other maitake strain did not.

• No participants stopped the study because of adverse effects.

• The findings are preliminary: the trial was small, short, limited to one population, and tested particular mushroom strains rather than maitake mushrooms in general.

Maitake mushrooms have long been studied for compounds that may affect immune and metabolic processes. This study asked a narrower question: could regular intake of maitake-containing bread influence cognitive performance in healthy older adults?

After 18 weeks, researchers saw a benefit on a cognitive screening measure in participants who received bread containing the Y10M strain. But participants who received bread containing a different strain, C5304, did not show the same advantage.

An Interesting Clue, With Limits

The Y10M group also showed greater activity of natural killer cells, a type of immune cell, and those changes were associated with cognitive-test scores.

But an association cannot show that immune changes caused the cognitive difference. Larger, independent studies would need to repeat the finding, test a wider range of people, and determine whether any effect is meaningful for day-to-day memory or long-term brain health.

There is another reason for restraint: two authors were affiliated with the company connected to the mushroom intervention. That does not dismiss the study, but it makes independent confirmation especially important. For now, maitake can remain a flavorful food within a varied eating pattern—not a proven cognitive supplement.

References:

Jogi EM, Kato MC, Masuda Y, Konishi M, Kuwabara N, Sato S, Nakagawa S, Yamasaki K, Aoki R, Ohno M, Ohata S, Kato S, Hashimoto M. Maitake Mushroom (Grifola frondosa) Enhances Cognitive Function in Healthy Older Japanese: A Randomized, Double-Blind, Placebo-Controlled Trial. J Nutr Sci Vitaminol (Tokyo). 2026;72(2):163-175. doi: 10.3177/jnsv.72.163. PMID: 42055721.