Although traditional Chinese medicine has long recognized the health benefits of edible mushrooms, it wasn’t until the late 20th century that western medicine began devoting resources to explore the science. Immune function has been one of the most promising areas of mushroom research thus far. A number of mushroom species have proven immune-boosting effects, both in vitro and in vivo.
Medicinal mushrooms work in a variety of ways. In many cases, the effective compounds are identified and isolated for study. Researchers often create extracts or derive fractions of specific compounds in order to concentrate the active compounds for maximum benefit. An in vivo study showed that compounds from shiitake mushroom (Lentinus edodes) and Turkey Tail (Trametes versicolor) stimulate interleukin beta in the liver and the spleen.1 In vitro experiments have identified a lignin from shiitake with antiviral and immune-boosting effects. It stimulates natural killer cell, macrophage, and T-cell activity.2 Turkey Tail mushroom stimulates the production of immunoglobulin M (a type of antibody) in in vitro experiments.3
In studies on mice, some parts of the reishi mushroom (Ganoderma lucidum) stimulate greater production of lymphocytes, white blood cells that are part of the immune system.4 Another edible mushroom, agaricus, boosts immune function in people with overall poor health. It helps to stimulate T-cell production and natural killer cell activity.5 Agarikon (Fomitopsis officinalis) is another immune-enhancing mushroom. Chinese researchers have demonstrated that it boosts humoral immunity (which involves antibodies), cellular immunity, and non-specific immunity.6
The body of research on edible mushrooms as anti-cancer agents is large and growing. One mushroom, Turkey Tail (Trametes versicolor), contains a polysaccharide, PSK, with proven anti-cancer effects. It helps inhibit the spread of cancer by acting on the enzymes associated with metastasis. It can also block the effects of certain carcinogens in the body.7
A compound found in maitake mushroom called MD-fraction has been proven effective in clinical trials against liver, breast, and lung cancers.8 In another clinical study, maitake mushroom was shown to inhibit metastasis and increase the activity of natural killer cells.9
Other mushroom species also show anti-cancer activity. Beta glucan from Agaricus blazei boosts natural killer cell activity in the spleens of mice and increases interleukins 12 and 18 and IFN-gamma (cytokines that stimulate immune activity).10 Patients suffering from gynecological cancers who were given an extract from Agaricus blazei had much greater natural killer cell activity compared to a control group; the patients also had fewer side effects from chemotherapy.11
Cordyceps is yet another mushroom that boosts natural killer cell activity, according to in vitro and in vivo studies.12 Reishi mushroom (Ganoderma lucidum) also boosts natural killer cell activity in cancer patients, and stimulates production of interferon and interleukin 2 and 6.13
Shiitake mushroom (Lentinus edodes) has similar anti-cancer effects. One of its active compounds, lentinan, reduced malignant tumors in mice by 94% and boosted levels of interleukin 1a and 2, interferon gamma, and tumor necrosis factor alpha.14 Another study showed that shiitake stimulated macrophage and natural killer cell activity in mice exposed to a potent carcinogen; 53% of the mice remained cancer free while none of the control mice remained cancer free.15 Poria cocos mushroom has been shown to have anti-cancer properties both in vitro and in vivo.16,17,18
Edible mushrooms also show promise for the treatment of human immunodeficiency virus (HIV). Betulinic acid from chaga mushroom (Inonotus obliquus) has shown to be of therapeutic value for people suffering from HIV.19 A polysaccharide found in Turkey Tail mushroom (Trametes versicolor) inhibits reverse transcriptase and protease, two enzymes required for virus replication.20,21 Turkey Tail also blocks a protein (GP12) on the HIV virus that gains entry into cells from harming receptors on CD4 immune cells.22 Like Turkey Tail, shiitake (Lentinus edodes) mushroom also inhibits HIV reverse transcriptase.23 In an in vitro study a fraction derived from shiitake, designated EP3, also suppressed replication of the HIV virus.24
1 Morinaga, H., et al. An in vivo study of hepatic and splenic interleukin-1-beta mRNA expression following oral PSK or LEM administration. Cancer Science. 1994. 85 (12), 1298-1303.
2 Yamamoto, Y., et al. Immunopotentiating activity of the water-soluble lignin rich fraction prepared from LEM—the extract of the solid culture medium of Lentinus edodes mycelia. Bioscience, Biotechnology, and Biochemistry. 1997. 61 (11), 1909-1912.
3 Maruyama, S., et al. Protein-bound polysaccharide-K (PSK) directly enhanced IgM production in the human B cell line BALL-1.
4 Yue, G.G., et al. Comparative studies on the immunomodulatory and antitumor activities of the different parts of fruiting body of Ganoderma lucidum and Ganoderma spores. Phytotherapy Research. 2008. 22 (10), 1282-1291.
5 Liu, Y., et al. Immunomodulating activity of Agaricus brasiliensis KA21 in mice and in human volunteers. Evidence-Based Complementary and Alternative Medicine. 2008. 5 (2), 205-219.
6 Wuliya, P., et al. The immune-potentiating effect of fomes officinalis polysaccharides. Journal of Xinjiang Medical University. 2003-06.
7 Fisher, M., and Yang, L.X. Anticancer effects and mechanisms of polysaccharide-K (PSK): implications of cancer immunotherapy. Anticancer Research. 2002. 22 (3), 1737-1754.
8 Kodama, N., et al. Can maitake MD-fraction aid cancer patients? Alternative Medicine Review. 2002. 7 (3), 236-239.
9 Kodama, N., et al. Effect of maitake (Grifola frondosa) D-fraction on the activation of NK cells in cancer patients.
10 Niu, Y.C., et al. Immunostimulatory activities of a low molecular weight antitumoral polysaccharide isolated from Agaricus blazei Murill (LMPAB) in Sarcroma 180 ascitic tumor-bearing mice. Die Pharmazie. 2009. 64 (7), 472-476.
11 Ahn, W.S., et al. Natural killer cell activity and quality of life were improved by consumption of a mushroom extract, Agaricus blazei Murill Kyowa, in gynecological cancer patients undergoing chemotherapy. International Journal of Gynecological Cancer. 2004. 14 (4), 589-594.
12 Xu, R.H., et al. Effects of Cordyceps sinensis on natural killer cell activity and colony formation of B16 melanoma. Chinese Medical Journal (English edition). 1992. 105 (2), 97-101.
13 Gao, Y., et al. Effects of Ganopoly (a Ganoderma lucidum polysaccharide extract) on the immune functions in advanced-stage cancer patients. Immunological Investigations. 2003. 32 (3), 210-215.
14 Yap, A.T., and Ng, M.L. The medicinal benefits of lentinan (beta-1, 3-D glucan) from Lentinus edodes (berk.) Singer (shiitake mushroom) through oral administration. International Journal of Medicinal Mushrooms. 2005. 7 (1-2), 175-192.
15 Kurashige, S., et al. Effects of Lentinus edodes, Grifola frondosa and Pleurotus ostreatus administration on cancer outbreak, and activities of macrophages and lymphocytes in mice treated with a carcinogen, N-butyl-Nbutanolnitrosoamine. Immunopharmacology and Immunotoxicology. 1997. 19 (2), 175-183.
16 Akihisa, T., et al. Tripterpene acids from Poria cocos and their anti-tumor-promoting effects. Journal of Natural Products. 2007. 70 (6), 948-953.
17 Jin, Y., et al. Antitumor activities of hetropolysaccharides of Poria cocos mycelia from different strains and culture media. Carbohydrate Research. 2003. 338 (14), 1517-1521.
18 Akihisa, T., et al. Anti-tumor-promoting effects of 25-methoxyporicoic acid A and other triterpene acids from Poria cocos. Journal of Natural Products. 2009. 72 (10), 1786-1792.
19 Cichewicz, R.H., and Kouzi, S.A. Chemistry, biological activity, and chemotherapeutic potential of betulinic acid for the prevention and treatment of cancer and HIV infection. Medicinal Research Reviews. 2004. 24 (1), 90-114.
20 Hirose, K., et al. A biological response modifier, PSK, inhibits reverse transcriptase in vitro. Biochemical and Biophysical Research Communications. 1987. 149 (2), 562-567.
21 Ng, T.B., et al. Polysaccharopeptide from the Turkey Tail fungus Trametes versicolor (L.:Fr.) Pilat inhibits human immunodeficiency virus type 1 reverse transcriptase and protease. International Journal of Medicinal Mushrooms. 2006. 8 (1), 39-43.
22 Collins, R.A., and Ng, T.B. Polysaccharopeptide from Coriolus versicolor has potential for use against human immunodeficiency virus type 1 infection. Life Sciences. 1997. 60 (25), 383-387.
23 Ngai, P.H., and Ng, T.B. Lentin, a novel and potent antifungal protein from shitake mushroom with inhibitory effects on activity of human immunodeficiency virus-1 reverse transcriptase and proliferation of leukemia cells. Life Sciences. 2003. 73 (26), 3363-3374.
24 Suzuki, H., et al. Structural characterization of the immunoactive and antiviral water-solubilized lignin in an extract of the culture medium of Lentinus edodes mycelia (LEM). Agricultural and Biological Chemistry. 1990. 54 (2), 479-497.