The role of your cancer health professional is to create an environment of openness and trust, and to help in making informed decisions about alternative/ complementary therapies. Collaboration will improve the safe integration of all therapies during your experience with cancer. The "Summary" and "Professional Evaluation/ Critique" sections of this Unconventional Therapies manual are cited directly from the medical literature, and are intended to help in the objective evaluation of alternative/ complementary therapies.
Summary
A literature search done in Medline and Cancerlit (1966-1999) did not retrieve any articles giving evidence that these mushroom therapies are effective as a treatment for cancer in humans. There have been no reports of controlled clinical studies testing the effects of these mushrooms as primary therapies as opposed to adjuvant therapies. Preliminary results that show efficacy for some of the treatments in vitro [in an artificial environment] and in mouse models indicate that further research is necessary.
Description/ Source/ Components
"Shiitake (Lentinula edodes) is the number one agricultural export of Japan, world production of this mushroom is second only to the common table mushroom (Agaricus bisporus)." (Jones Feb 1998)
"When the powdered mushroom [shiitake] was broken down into various fractions, the C-(or lipid fraction) and the D-fraction, consisting of soluble polysaccharides including lentinan, were the most active fractions taken orally." (Jones Feb 1998)
Krestin (PSK) is a protein-bound polysaccharide preparation from Coliolus versicolor. (Ebina)
PSK "consists predominantly of glucan and approximately 25% tightly bound protein." (Spencer)
"Reishi or ganoderma mushrooms are usually taken in different formulas. For example, there is Astra 8 which also contains astragalus, ginseng and licorice. Another formula is Power Mushrooms which also contains shiitake and polyporus." (Ontario)
"Since the early 1900's maitake [Grifola frondosa] products have been available throughout North America in the form of dietary supplements (liquid and powder extracts, tablets, etc.) and in the form of the dried mushroom for cooking." (Jones Dec 1998)
Powder from the maitake mushroom is available in pill form. (Ontario)
The intake amount for maitake varies according to the metabolic type and condition of the patient. (Diamond)
"Maitake and mushroom formulas such as Astra 8 and Power Mushrooms are available in most health food stores. Dried and fresh shiitake mushrooms are available at most Asian markets. Krestin is available only from the manufacturer, Kureha Chemical Industry Limited, Tokyo, Japan." (Ontario)
History
"The shiitake mushroom has been used in traditional Chinese medicine to strengthen immune resistance to disease. The Chinese regard shiitake mushrooms as one of the most beneficial botanical medicines. Chinese legends refer to it as a plant that gives eternal youth and longevity." (Marti)
"The medicinal fungus most commonly known as reishi... has long been revered as a nontoxic, longevity-promoting tonic... In Japan, the dried mushroom was hung in the home or its entranceway as a talisman to ward off evil." (Jones Aug 1998)
"The main research on maitake has centered on its antitumor activity and its activity with regard to cholesterol, diabetes, and hypertension. These kinds of studies were previously done on reishi and shiitake mushrooms." (Jones Dec 1998)
Proponent/ Advocate Claims
"Of an estimated 700 species of known edible mushrooms, up to 200 may have medicinal properties." (Jones Feb 1998)
Shiitake:
"Supporters state that shiitake has an anti-cancer effect. They claim shiitake mushrooms contain large amounts of protein, fibre, B vitamins, vitamin D and minerals such as calcium, phosphorous and iron. Lentinan, a compound made from shiitake mushrooms, has been approved in Japan for the treatment of stomach cancer." (Ontario)
"Shiitake mushrooms contain a polysaccharide complex, lentinan, which stimulates the production of T lymphocytes and macrophages, specifically interleukin." (Marti)
"Excluding one or using any one fraction alone resulted in less activity than from the whole mushroom." (Jones Feb 1998)
"Shiitake acted, according to Nanba and Kuroda, 'not only by activation of various effector cells (macrophages, natural killer cells, T cells, etc.)... but also by potentiating the cellular functions and preventing a decrease of immune functions of the tumor-bearing host.' (Nanba)" (Jones Feb 1998)
"Japanese Scientists in 1970 reported that polysaccharide preparations from the shiitake mushroom, commonly available in groceries, markedly inhibited the growth of induced sarcomas in mice, resulting in 'almost complete regression of tumors with no sign of toxicity.'" (Walters)
Krestin:
"PSK [Krestin] was effective against various allogeneic and syngeneic animal tumors and has been given orally to cancer patients. Various suppressed or enhanced immune responses of tumor-bearing animals were restored to normal levels by the administration of PSK in the tumor models tested. The killer T cell activity was augmented in tumor-bearing mice by intraperitoneal or oral administration of PSK." (Tsukagoshi)
"Krestin is a Japanese mushroom extract. Advocates claim that it enhances your immune system functioning by increasing the production of T-cells." (Ontario)
"The prognosis of operable breast cancer patients with vascular invasion was improved by immunochemotherapy using PSK [Krestin]." (Iino)
PSK has shown significant effectiveness as an adjuvant therapy. "In colon cancer as adjuvant therapy, the PSK-treated patients had a 30% 8-year disease free survival as compared with 10% for the control group. When added to radiation therapy as treatment for stage III non-small cell lung cancer, the 5-year survival was 22% compared with the control survival of 5%. (Hayakawa)
...In a randomized study of 158 patients with esophageal cancer treated with radiation, there was a statistically significant improvement in survival in those treated with PSK as well. (Ogoshi)" (Spencer)
Reishi:
"Supporters argue that the reishi mushroom is very effective for stopping tumour growth." (Ontario)
"...reishi may be useful in the form of a supplement during radiotherapy or chemotherapy to reduce various side effects, among them, bone marrow suppression and fatigue. Indeed, the immunorestorative activity of reishi may afford a degree of protection from the side effects of radiotherapy." (Jones Aug 1998)
Maitake:
"Supporters argue that maitake mushrooms have an important anti-tumour effect." (Ontario)
"According to researchers at the National Cancer Center in Japan, complete tumor elimination was experienced in about 80% of cancer-induced animals fed extracts from maitake, shiitake, and reishi mushrooms. Compounds of each of these mushrooms increase the tumor-fighting activity of NK cells [natural killer cells of the immune system] and improve antibody responses, but maitake seems to have the strongest and most consistent effect... Unlike other mushroom extracts, the maitake extract shows strong anticancer activity even when administered orally." (Diamond)
"At the University of Massachusetts at Amherst, in 1998, tests with maitake found significant inhibitory activity in a water extract of the mushroom against human cervical cancer cells and human T4 leukemic cells [in vitro]. Given the potency of the extract, the researchers concluded that further tests of the mushroom beyond their preliminary findings are definitely warranted." (Jones Dec 1998)
"Maitake has shown antitumor activity when the mushroom was orally administered in tumor-bearing mice... Complete tumor regression was found in every mouse." (Jones Dec 1998)
Preliminary non-randomized clinical studies were observed and reported by medical doctors in Japan who have tried Maitake D-fraction and/or crude tablets for their cancer patients. "Though preliminary, the results have indicated that Maitake is effective to breast, lung and liver cancers but much less effective against bone, stomach cancers and acute type leukemia. It should be noted however, that more than 90% of the patients have been ameliorated from chemotherapy side-effects, such as leukopenia, depilation, vomiting, and lost appetite. Also, the severe pain of terminal cancers is claimed to be mitigated. These preliminary data suggest that further controlled study should be conducted." (Nanba 1997)
Professional Evaluation/ Critique
According to a literature search done in Medline and Cancerlit, no study has been published that shows that any of the mushroom therapies have efficacy as a cancer cure for humans.
A study done by Haranaka and associates tested the capacity for tumour necrosis factor (TNF) production and the antitumor activity of traditional Chinese mushrooms. They found that neither zhu-ling-tang nor krestin showed any antitumor activity. Both mushrooms produced very low TNF activity. The TNF capacity for production broadly parallels the survival rate of the mice transplanted with tumours. (Haranaka)
"Suto and colleagues found no survival benefit to PSK in hepatocellular carcinoma patients after treatment with various standard therapies. (Suto)" (Spencer)
Toxicity/ Risks
Shiitake:
"Allergic type skin reactions are common with mushrooms, especially raw ones... There have been reports of toxicoderma, a skin disease... Critics argue that prolonged and intense exposure to shiitake spores can be dangerous. Workers exposed to high levels of such spores have been known to develop an occupational disease known as Mushroom Worker's Lung. However, the relevance of such findings to the ingestion of mushrooms is uncertain." (Ontario)
Flagellate skin lesions occur in some patients after eating the mushroom Lentinus edodes [shiitake]. (Hanada)
"It has been associated with severe dermatitis. One publication described 51 such complications." (Ernst)
The shiitake mushroom contains agaritine, a hydrazine that has been shown carcinogenic in animals. (Shils)
Reishi:
"In some people first taking reishi powder extract, temporary symptoms may appear in the form of sleepiness, rashes, bloating, thirstiness, frequent urination, loose stool and abnormal sweating." (Jones Aug 1998)
Maitake:
"Little or no information regarding Maitake toxicity is available. Most studies report no side effects. Because potential toxicity exists from mistaken mushroom identity, use caution when obtaining this particular natural product." (Anonymous 1998)
Costs
Maitake and mushroom formulas containing reishi are available for approximately $30. Dried and fresh shiitake usually costs between $0.50 to $3.50 per ounce. (Ontario, 1994)
References
Anonymous. Maitake. Facts and Comparisons Review of Natural Products 1998 June.
Diamond WJ, et al. An alternative medicine definitive guide to cancer. Tiburon, California: Future Medicine Publishing, Inc., 1997:113,483,833.
Ebina T. Antitumor effect of various basidiomycetes preparations (Meeting abstract). Cancer Conference 12th Asia Pacific, p.59. Singapore, Oct 17-20.
Ernst E. Harmless herbs? A review of the recent literature. Am J Med 1998;104:170-178.
Hanada K, Hashimoto I. Flagellate mushroom (shiitake) dermatitis and photosensitivity. Dermatology 1998;197:255-7.
Haranaka K, et al. Antitumor activities and tumor necrosis factor producibility of traditional Chinese medicines and crude drugs. Cancer Immunology, Immunotherapy 1985;20:1-5.
Hayakawa K, et al. Effect of krestin (PSK) as adjuvant treatment on the prognosis after radical radiotherapy in a patient with non-small cell lung cancer. Anticancer Res 1993;13:1815.
Iino Y, et al. Eight-year results of adjuvant immunochemotherapies vs chemotherapy in the treatment of operable breast cancer (Meeting Abstract). 18th International Congress of chemotherapy. Stockholm, Sweden, p.162. June 27-July 2, 1993.
Jones K. Shiitake: a major medicinal mushroom. Alternative and Complementary Therapies 1998 Feb.: 53-59.
Jones K. Maitake: a potential medicinal food. Alternative and Complementary Therapies 1998 Dec:420-429.
Jones K. Maitake: a potential medicinal food. Alternative and Complementary Therapies 1998 Aug.:256-266.
Marti JE. Alternative health medicine encyclopedia: the authoritative guide to holistic and nontraditional health practices. Toronto: Gale Research Inc., 1995:91,269.
Nanba H, et al. Antitumor mechanisms of orally administered shiitake fruit bodies. Chem Pharm Bull 1987;35:2459-2464.
Nanba H. Therapeutic value of Maitake D-fraction for various cancer patients (Meeting abstract). Adjuvant Nutrition in Cancer Treatment Symposium, Tampa, Florida, September 27, 1997.
Ogoshi K, et al. Immunotherapy for esophageal cancer: a randomized trial in combination with radiotherapy and radiochemotherapy. Am J Clin Oncol 1995;18:216.
Ontario Breast Cancer Information Exchange Project. Guide to unconventional cancer therapies. 1st ed. Toronto: Ontario Breast Cancer Information Exchange Project, 1994:166-169.
Shils ME, et al. Modern nutrition in health and disease, 9th ed. Baltimore: Williams & Wilkins, 1999: 1257.
Spencer JW, Jacobs JJ. Complementary/alternative medicine: an evidence based approach. Toronto: Mosley, 1999:143-4.
Suto T, et al. Clinical study of biological response modifiers as maintenance therapy for hepatocellular carcinoma. Cancer Chemother Pharmacol 1994; 33 (suppl):S145.
Tsukagoshi S, et al. Krestin (PSK). Cancer treatment reviews 1984:11:131-155.
Walters R. Options: The alternative cancer therapy book. Garden City Park, New York: Avery Publishing Group Inc., 1993:171.
Revised February 2000