Shiitake Mushroom 

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The use of dietary supplements by patients with cancer has increased significantly over the past 2 decades despite insufficient evidence of safety and effectiveness. Finding reliable sources of information about dietary supplements can be daunting. Patients typically rely on family, friends, and the Internet, often receiving misleading information.

The ASCO Post’s Integrative Oncology series is intended to facilitate the availability of evidence-based information on integrative and complementary therapies commonly used by patients with cancer. We chose shiitake mushroom for this issue because its extracts are used increasingly by patients with cancer.

Compiled by Barrie R. Cassileth, PhD, and Jyothi Gubili, MS, Memorial Sloan-Kettering Cancer Center. The About Herbs website is managed by K. Simon Yeung, PharmD, MBA, Lac, Memorial Sloan-Kettering Cancer Center.

Scientific name: Lentinula edodes
Common names: Forest mushroom, lentinula, pasania fungus, black mushroom, hua gu


Shiitake, an edible mushroom indigenous to East Asia, is cultivated worldwide for its health benefits. Both the fresh and dried forms of the mushroom are a staple in East Asian cooking. Shiitake is considered a medicinal mushroom based on its use in traditional medicine. It is also valued as an anticancer agent.

Lentinan, a polysaccharide isolated from shiitake, has been well studied and is thought responsible for the mushroom’s beneficial effects. An injectable form of lentinan is used for cancer treatment in some countries but has not been evaluated in large clinical trials.

Shiitake is available in most supermarkets, in many restaurants and in Asian grocery stores.

The Science

Lentinan demonstrated anticancer effects in colon cancer cells in vitro,1 which may be due to suppression of cytochrome P450 1A enzymes that metabolize procarcinogens to their active form.2 Lentin, the protein component of shiitake, showed antifungal and antiproliferative properties and suppressed the activity of human immunodeficiency virus–1 reverse transcriptase.3

Studies of shiitake extracts indicate antiproliferative,4 immunostimulatory,4 hepatoprotective,5 antimutagenic,6 and anticaries7 effects in vitro and in mice. But a clinical trial failed to show efficacy of an oral shiitake extract in the treatment of prostate cancer.8

Nevertheless, small studies conducted in Japan using an oral formulation of superfine dispersed lentinan showed improved quality of life and survival in patients with hepatocellular carcinoma9 as well as gastric,10 colorectal,11 and pancreatic12 cancers. Larger trials are warranted.

Adverse Effects

Case Reports: Chronic hypersensitivity pneumonitis was observed in a patient with lung cancer following exposure to shiitake spores.13 Prolonged consumption of shiitake mushrooms resulted in dermatitis,14 photosensitivity,15 eosinophilia, and gastrointestinal upset.16 Food allergy, manifested as esophageal symptoms, was reported following consumption of shiitake mushroom.17 ■


1. Ng ML, Yap AT: Inhibition of human colon carcinoma development by lentinan from shiitake mushrooms (Lentinus edodes). J Altern Complement Med 8:581-589, 2002.

2. Okamoto T, Kodoi R, Nonaka Y, et al: Lentinan from shiitake mushroom (Lentinus edodes) suppresses expression of cytochrome P450 1A subfamily in the mouse liver. Biofactors 21:407-409, 2004.

3. Ngai PH, Ng TB: 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 Sci 73:3363-3374, 2003.

4. Israilides C, Kletsas D, Arapoglou D, et al: In vitro cytostatic and immunomodulatory properties of the medicinal mushroom Lentinula edodes. Phytomedicine 15:512-519, 2008.

5. Akamatsu S, Watanabe A, Tamesada M, et al: Hepatoprotective effect of extracts from Lentinus edodes mycelia on dimethylnitrosamine-induced liver injury. Biol Pharm Bull 27:1957-1960, 2004.

6. de Lima PL, Delmanto RD, Sugui MM, et al: Letinula edodes (Berk.) Pegler (Shiitake) modulates genotoxic and mutagenic effects induced by alkylating agents in vivo. Mutat Res 496:23-32, 2001.

7. Shouji N, Takada K, Fukushima K, et al: Anticaries effect of a component from shiitake (an edible mushroom). Caries Res 34:94-98, 2000.

8. deVere White RW, Hackman RM, et al: Effects of a mushroom mycelium extract on the treatment of prostate cancer. Urology 60:640-644, 2002.

9. Isoda N, Eguchi Y, Nukaya H, et al: Clinical efficacy of superfine dispersed lentinan (beta-1,3-glucan) in patients with hepatocellular carcinoma. Hepatogastroenterology 56:437-41, 2009.

10. Oba K, Kobayashi M, Matsui T, et al: Individual patient based meta-analysis of lentinan for unresectable/recurrent gastric cancer. Anticancer Res 29:2739-2745, 2009.

11. Hazama S, Watanabe S, Ohashi M, et al: Efficacy of orally administered superfine dispersed lentinan (beta-1,3-glucan) for the treatment of advanced colorectal cancer. Anticancer Res 29:2611-2617, 2009.

12. Shimizu K, Watanabe S, Watanabe S, et al: Efficacy of oral administered superfine dispersed lentinan for advanced pancreatic cancer. Hepatogastroenterology 56:240-244, 2009.

13. Suzuki K, Tanaka H, Sugawara H, et al: Chronic hypersensitivity pneumonitis induced by Shiitake mushroom spores associated with lung cancer. Intern Med 40:1132-1135, 2001.

14. Garg S, Cockayne SE: Shiitake dermatitis diagnosed after 16 years! Arch Dermatol 144:1241-1242, 2008.

15. Hanada K, Hashimoto I: Flagellate mushroom (Shiitake) dermatitis and photosensitivity. Dermatology 197:255-257, 1998.

16. Levy AM, Kita H, Phillips SF, et al: Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms. J Allergy Clin Immunol 101:613-620, 1998.

17. Goikoetxea MJ, Fernández-Benítez M, Sanz ML: Food allergy to Shiitake (Lentinus edodes) manifested as oesophageal symptoms in a patient with probable eosinophilic oesophagitis. Allergol Immunopathol (Madr) 37:333-334, 2009.