Maitake mushroom (Grifola frondosa)

Tier 3 — weak evidence · Immunity · Blood sugar · Cancer adjunct

Contains the unique D-fraction beta-glucan that activates natural killer cells and macrophages. Small clinical trials show improved immune markers in cancer patients alongside chemotherapy and significant blood sugar reduction in type 2 diabetes. Used in Japanese integrative oncology. May enhance effects of blood thinners and diabetes medications — monitor if on these drugs.

Dose: 35–70 mg/day D-fraction extract or 3–7 g/day whole mushroom powder