Shiitake

Related Terms

Active hexose correlated compound (AHCC), Agaricus edodes, basidiomycete, beta-glucan, black forest mushroom, C-fraction, C-lipid-fraction, Chinese black mushroom, Coprinopsis ciner, Cortinellus shiitake, D-fraction, d-glucopyranose, D-lipid-fraction, delicious mushroom, eritadenine, F-249, flower mushroom, forest mushroom, fragrant mushroom, hagu (Chinese), hed hom (Thai), heteroglycan fraction, hua gu (Chinese), huagu (Chinese), JLS-18, JLS-S001, king of mushrooms, L. edodes (Berk.) Pegler, LC-1, LEM, lemtemin, lenthionine, lentiane, lentin, Lentinan?, Lentinan enodes, lentinan (LNT), lentinula, Lentinula edodes, Lentinus edodes,Lentinus edodes mycelium, Lentinus edodes mycelium (LEM) extract, linoleic acid, LNT, Marasmiaceae (family), mentemin, monarch of mushrooms, mushroom, mycelia, mycelium, pasania fungus, Phanerochaete chrysosporium, polyphenols, Polyporaceae (family), polysaccharide L-II, pyogo (Korean), shii mushroom, shiitake medical mushroom, shiitake mushroom extract (SME), shiitake mushroom mycelial extract, shiitake mycelium, shitake, snake butter, Tricholomopsis edodes, winter mushroom, xianggu (Chinese), xylanase enzymes.

Background

Shiitake mushrooms were originally cultivated on natural oak logs and only grown in Japan but are now available in the United States. These mushrooms are large, black-brown, and have an earthy rich flavor. This fungus is consumed in foods such as stir-fries, soups, and as a meat substitute.
Shiitake contains proteins, fats, carbohydrates, soluble fiber, vitamins (A, B, B12, C, D, niacin), and minerals. Commercial preparations often use the powdered mycelium of the mushroom before the cap and stem grow. This preparation is called Lentinus edodes mycelium extract (LEM). LEM is rich in polysaccharides and lignans.
Shiitake has been taken by mouth for boosting the immune system, decreasing cholesterol levels, and for anti-aging. Lentinan, derived from shiitake (Lentinus edodes), has been injected as an adjunct treatment for cancer and HIV infection, although currently high quality human scientific evidence is lacking for many proposed indications. Purified lentinan is considered a drug in Japan.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


Laboratory, animal, and human studies of lentinan have shown positive results in cancer patients when used in addition to chemotherapy drugs. Further well-designed clinical trials on all types of cancer are required to confirm these results. Shiitake mushroom extract (SME) used alone did not show benefit in prostate cancer patients in one study. Please check with a medical oncologist and pharmacist before taking any therapies.

 C


Laboratory, animal, and human studies of lentinan have shown positive results in cancer patients when used in addition to chemotherapy drugs. Further well-designed clinical trials on all types of cancer are required to confirm these results. Shiitake mushroom extract (SME) used alone did not show benefit in prostate cancer patients in one study. Please check with a medical oncologist and pharmacist before taking any therapies.

 C


Based on preliminary study, lentinan could modulate the immune function and reduce the recurrence rate of genital warts. Further well-designed studies are needed to confirm these results. Currently, more proven therapies are recommended.

 C


Based on preliminary study, lentinan could modulate the immune function and reduce the recurrence rate of genital warts. Further well-designed studies are needed to confirm these results. Currently, more proven therapies are recommended.

 C


Based on preliminary studies, lentinan may increase CD4 counts and may qualify in future multi-drug studies in HIV patients. Further well-designed studies are needed to confirm these results. Side effects have been reported and more proven therapies are recommended at this time.

 C


Based on preliminary studies, lentinan may increase CD4 counts and may qualify in future multi-drug studies in HIV patients. Further well-designed studies are needed to confirm these results. Side effects have been reported and more proven therapies are recommended at this time.

 C


Currently, there is limited human evidence supporting the role of lentinan and shiitake as an immunomodulator. Additional study is needed in this area.

 C


Currently, there is limited human evidence supporting the role of lentinan and shiitake as an immunomodulator. Additional study is needed in this area.

 C
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (over 18 years old)
There is no proven effective medicinal dose for shiitake. Traditionally, 6-16 grams of the whole, dried shiitake mushroom has been ingested daily. It is typically eaten in soups or taken as a decoction (i.e. boiled for 10-20 minutes, cooled, strained, and consumed). A dose of 1-3 grams of Lentinus edodes mycelium (LEM) has been taken two to three times per day. Shiitake-containing capsules have been taken three times daily for six months. A dose of 4 grams of shiitake powder has also been taken daily for 10 weeks.
Injections should only be given by a qualified healthcare provider.
Intranasal application of lentinan has been studied at a dose of 1 milligram per kilogram, used three times at two-day intervals. Safety and effectiveness have not been proven.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
Although not well studied in humans, lentinan and shiitake extracts may interact with antifungals, antivirals, antioxidants, and immunomodulators. Caution is advised.
Lentinan has been used as an adjunct with cancer therapies to prolong survival time and increase quality of life.
Based on preliminary animal study, shiitake may reduce blood levels of free cholesterol, triglycerides, and phospholipids.
In a laboratory study, essential oil from shiitake inhibited platelet aggregation and therefore may increase the risk of bleeding when taken with drugs that also increase bleeding risk like warfarin (Coumadin?) or ibuprofen (Advil?, Aleve?). Lentinan, the polysaccharide derivative of shiitake, may cause mildly abnormal blood cell counts (thrombocytopenia).
Lentinus edodes has been shown to inhibit cyclooxygenase activity in laboratory study and therefore may interact with drugs like Tylenol? or Celebrex?.
Mushroom polysaccharides, especially beta-glucans such as lentinan from Lentinus edodes, may interfere with the way the liver breaks down certain drugs (through the suppression of CYP1As). Consult a qualified healthcare professional, including a pharmacist, to check for interactions.
Taking didanosine (ddI, Videx?), the nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral drug for HIV, with lentinan (the polysaccharide derivative of shiitake) may help to increase CD4 levels in HIV positive patients.
Lentinan may cause increased sun sensitivity that can be worsened by drugs like Retin-A? and tetracycline antibiotics.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

DeVere White RW, Hackman RM, Soares SE, et al. Effects of a mushroom mycelium extract on the treatment of prostate cancer. Urology 2002;60(4):640-644.
Fujiwara K, Sato T, Yonei T, et al. [A case of chronic hypersensitivity pneumonitis induced by shiitake mushroom spores]. Nihon Kokyuki Gakkai Zasshi 2000;38(12):908-913.
Gordon M, Bihari B, Goosby E, et al. A placebo-controlled trial of the immune modulator, lentinan, in HIV-positive patients: a phase I/II trial. J Med 1998;29(5-6):305-330.
Hanada K, Hashimoto I. Flagellate mushroom (Shiitake) dermatitis and photosensitivity. Dermatology 1998;197(3):255-257.
Hitosugi M, Kitamura O, Takatsu A, et al. Autopsy case of duodenal obstruction from impacted mushroom. J Gastroenterol 1998;33(4):562-565.
Jong SC, Birmingham JM. Medicinal and therapeutic value of the shiitake mushroom. Adv Appl Microbiol 1993;39:153-184.
Lippert U, Martin V, Schwertfeger C, et al. Shiitake dermatitis. Br J Dermatol 2003;148(1):178-179.
Matsui S, Nakazawa T, Umegae Y, et al. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Intern Med 1992;31(10):1204-1206.
Moore JE, Convery RP, Millar BC, et al. Hypersensitivity pneumonitis associated with mushroom worker's lung: an update on the clinical significance of the importation of exotic mushroom varieties. Int Arch Allergy Immunol 2005;136(1):98-102.
Ng ML, Yap AT. Inhibition of human colon carcinoma development by lentinan from shiitake mushrooms (Lentinus edodes). J Altern Complement Med 2002;8(5):581-589.
Nimura H, Mitsumori N, Takahashi N, et al. [S-1 combined with lentinan in patients with unresectable or recurrent gastric cancer] Gan To Kagaku Ryoho. 2006 Jun;33 Suppl 1:106-9.
Sastre J, Ibanez MD, Lopez M, et al. Respiratory and immunological reactions among Shiitake (Lentinus edodes) mushroom workers. Clin Exp Allergy 1990;20(1):13-19.
Shimada S, Komamura K, Kumagai H, et al. Inhibitory activity of shiitake flavor against platelet aggregation. Biofactors 2004;22(1-4):177-179.
Tarvainen K, Salonen JP, Kanerva L, et al. Allergy and toxicodermia from shiitake mushrooms. J Am Acad Dermatol 1991;24(1):64-66.
Yang P, Liang M, Zhang Y, Shen B. Clinical application of a combination therapy of lentinan, multi-electrode RFA and TACE in HCC. Adv Ther 2008 Aug;25(8):787-94.