Maitake demonstrated anticancer effects in laboratory studies. Research is underway to test its anticancer effects in humans.
Maitake is a mushroom that traditionally has been used in Japan and China as part of the diet and to treat diabetes and hypertension. Like other medicinal mushrooms, maitake contains a complex sugar called beta-glucan. In laboratory and human studies, maitake extract was able to stimulate various cells and factors in the immune system. Studies in animals show that it slows the growth of certain tumors and lowers blood sugar levels. More studies are being conducted to determine if maitake has the same effects in humans.
To prevent and treat cancer
Laboratory studies and small uncontrolled studies in humans show that maitake extracts slow the growth of tumors and stimulate certain immune cells.
To manage diabetes
Maitake reduces blood glucose levels in rats.
To lower high cholesterol
No scientific evidence supports this use.
To lower high blood pressure
There are no studies to support this claim.
As an immune stimulant
Maitake stimulates the activity of certain immune cells in laboratory studies and in mice. It has also been shown to stimulate immune function in a small group of cancer patients.
To lose weight
This claim is not backed by research.
Do Not Take If
You are taking blood sugar-lowering medications: Maitake can increase their effects.
You are taking warfarin: Maitake may interact with warfarin resulting in an elevated international normalized ratio (INR).
An increased number of white blood cells which may indicate an allergic reaction.
Maitake is an edible mushroom consumed widely in Asia as food and used in traditional medicine to treat diabetes and hypertension. Its extracts are commercially available as dietary supplements marketed to “enhance immune function” and to treat HIV and cancer. Beta 1,6-glucan, a protein bound polysaccharide, has been identified as the active constituent. Maitake extracts exhibited hypoglycemic effects in a few studies (9)(12). Preliminary data also suggest that maitake may be useful in inducing ovulation in patients with polycystic ovary syndrome (22).
In other studies, maitake demonstrated antitumor effects (16), enhanced bone marrow colony formation, reduced doxorubicin toxicity (11), and inhibited tumor metastasis in vitro (13). In a study done in mice, an orally administered extract promoted maturation of hematopoietic cells to functionally active myeloid cells and enhanced peripheral blood leukocyte recovery following chemotoxic bone marrow injury (17). A novel polysaccharide, MZF, was shown to induce dendritic cell maturation and enhanced antitumor response (20). Maitake also enhanced interferon activity against bladder cancer cells (18) and alleviated inflammation associated with inflammatory bowel disease (19).
In a small non-controlled study, tumor regression or significant improvements in symptoms were observed in half of the subjects who took Maitake extract (5). In a trial of postmenopausal breast cancer patients, oral administration of a maitake extract was shown to have immunomodulatory effects (14); and to enhance neutrophil and monocyte function in patients with myelodysplastic syndrome (25). More studies are underway to establish maitake’s anticancer potential.
Maitake mushroom is an edible fungus. The whole mushroom can be fried or boiled.
Mechanism of Action
Maitake is thought to exert its effects through its ability to activate various effector cells, such as macrophages, natural killer cells, and T cells, as well as interleukin-1 and superoxide anions (2)(3)(4)(13). Studies also suggest possible hypoglycemic activity (9). The antidiabetic effect of alpha-glucan may be due to its effects on insulin receptors by increasing insulin sensitivity and ameliorating insulin resistance of peripheral target tissues (12).
Maitake extract enhanced the growth and differentiation of mouse bone marrow cells treated with doxorubicin, a chemotherapeutic agent (11). In addition, maitake extract may modulate antigen presentation as evidenced by protection of mice against tumor implantation following transfer of dendritic cells from tumor-bearing mice that were treated with maitake extract (15).
In other studies, maitake D fraction demonstrated antitumor activity by upregulating expression of a proapoptotic gene, BAK-1 (23); and prevented breast carcinogenesis, blocked tumor invasiveness, reduced angiogenesis, and increased overall survival in a murine model (26). In addition, maitake polysaccharides were found to induce apoptosis GFPs induced via the mitochondrial-dependent apoptotic pathway in human breast cancer cells (27); the beta glucan GFPBW1 also showed antitumor effects that are thought in part due to activation of macrophages via the Dectin-1/Syk/NF-κB signaling pathway (24); and an orally administered maitake alpha-glucan was found to activate dendritic cells and macrophages in Peyer’s patches, resulting in induction of systemic antitumor T-cell response (28).
Maitake also exerted antidepressant effects in mice, involving activation of the α-Amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors, which are important mediators for the treatment of depression (29).
Maitake may not be appropriate for those taking hypoglycemic medications because it can have synergistic effects (9).