Parts Used & Where Grown
Wild shiitake mushrooms are native to Japan, China, and other Asian countries and typically grow on fallen broadleaf trees. Shiitake is now widely cultivated throughout the world, including the United States. The fruiting body is used medicinally.
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Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
This supplement has been used in connection with the following health conditions:
Refer to label instructions
One study found that shiitake formulations containing Lentinus edodes mycelium may help decrease blood markers of liver inflammation
An uncontrolled trial found that Reference shiitake formulations containing Lentinus edodes mycelium (LEM— the powdered mycelium of the mushroom before the cap and stem grow) may help decrease blood markers of liver inflammation.2 One marker of hepatitis B infection in the blood (HBeAg) disappeared in 14% of the patients in this trial. Given the preliminary nature of the research, more information is needed to determine if LEM is effective for hepatitis.
HIV and AIDS Support
Refer to label instructions
Shiitake is medicinal mushroom immune-modulating effects that may be beneficial for people with HIV infection.
Immune-modulating plants that could theoretically be beneficial for people with HIV infection include Reference Asian ginseng, Reference eleuthero, and the medicinal mushrooms Reference shiitake and Reference reishi. One preliminary study found that steamed then dried Asian ginseng (also known as red ginseng) had beneficial effects in people infected with HIV, and increased the effectiveness of the anti-HIV drug, AZT.3 This supports the idea that immuno-modulating herbs could benefit people with HIV infection, though more research is needed.
Refer to label instructions
Shiitake supports the immune system and protects against microbes.
Herbs that support a person’s Reference immune system in the fight against microbes include the following: Reference American ginseng, Reference andrographis, Reference Asian ginseng, Reference astragalus, coriolus, Reference eleuthero, Reference ligustrum, Reference maitake, Reference picrorhiza, Reference reishi, Reference schisandra, and Reference shiitake.
Refer to label instructions
Lentinan, a carbohydrate in shiitake mushrooms, has been found to have beneficial effects on cancer patients’ immune systems, including improved longevity and survival rates.
Several trials studying cancer patients have investigated the effects of lentinan, a carbohydrate found in Reference shiitake (Lentinus edodes) mushrooms.4 , 5 , 6 , 7 Injection of lentinan repeatedly has been found to have beneficial effects on the Reference immune systems of cancer patients.8 , 9 Two trials reported that lentinan injections prolonged life in people with a variety of advanced cancers.10 , 11 Another trial found that intravenous lentinan increased five-year survival rates in prostate cancer patients compared with those not given lentinan.12 It is unknown whether consumption of shiitake mushrooms or lentinan supplements would have the same effects reported in studies using injectable lentinan.
Traditional Use (May Not Be Supported by Scientific Studies)
Shiitake has been revered in Japan and China as both a food and medicinal herb for thousands of years. Wu Ri, a physician from the Chinese Ming Dynasty era (A.D. 1368–1644), wrote extensively about this mushroom, noting its ability to increase energy, cure Reference colds, and eliminate worms.1
How It Works
How It Works
Shiitake contains proteins, fats, carbohydrates, soluble Reference fiber, vitamins, and minerals. In addition, shiitake’s key ingredient—found in the fruiting body—is a polysaccharide called lentinan. Commercial preparations employ 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.
One preliminary trial suggested that oral shiitake may be useful for people with Reference hepatitis B.13 A highly purified, intravenous form of lentinan is used in Japan and has been reported to increase survival in people with recurrent stomach cancer, particularly when used in combination with chemotherapy.14 Similar findings have been found in one small clinical trial with people suffering from pancreatic cancer.15 Case reports from Japan suggest that intravenous lentinan may be helpful in treating people with Reference HIV infection.16 However, large-scale clinical trials to confirm this action have not yet been performed.
Oral supplementation of lentinan from shiitake has been shown to significantly reduce the recurrence rate of genital warts (condyloma acuminata). A preliminary trial involving a group of men and women with genital warts found that those who took 12.5 mg of lentinan twice a day for two months after laser surgery had significantly fewer recurrences (10.53% recurrence rate) compared to those who only had the laser surgery (47.06% recurrence rate).17
How to Use It
The traditional intake of the whole, dried shiitake mushroom is 6–16 grams per day.18 The mushroom is typically eaten in soups or taken as a decoction (i.e., boiled for 10–20 minutes, cooled, strained, and drunk). Recommended intake of LEM is 1–3 grams two to three times per day. Purified lentinan is considered a drug in Japan and is not currently available as an herbal supplement in North America.
Interactions with Supplements, Foods, & Other Compounds
Interactions with Medicines
Certain medicines interact with this supplement.
Replenish Depleted Nutrients
Reduce Side Effects
Lentinan is a complex sugar found in shiitake mushrooms (Lentinas edodes) and is recognized as an immune modulator. In an early human trial, 88 HIV-infected people received didanosine (400 mg per day) plus a 2 mg lentinan injection per week.19 Didanosine-lentinan combination therapy improved CD4 immune cell counts for a significantly longer period than didanosine alone. Lentinan is under investigation as an adjunct therapy to be used with didanosine for HIV infection.20 Oral preparations of shiitake are available, but it is not known if they would be an effective treatment with didanosine for HIV infection.The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
Potential Negative Interaction
1. Jones K. Shiitake: The Healing Mushroom. Rochester, VT: Healing Arts Press, 1995.
2. Harada T, Kanetaka T, Suzuki H, Suzuki K. Therapeutic effect of LEM (extract of cultured Lentinus edodes mycelia) against HBeAg-positive chronic hepatitis B. Gastroenterol Int 1988;1(suppl 1):abstract 719.
3. Cho YK, Kim Y, Choi M, et al. The effect of red ginseng and zidovudine on HIV patients. Int Conf AIDS 1994;10:215 [abstract no. PB0289].
4. Miyakoshi H, Aoki T, Mizukoshi M. Acting mechanism of lentinan in human—II. Enhancement of non-specific cell-mediated cytotoxicity as an interferon inducer. Int J Immunopharmacol 1984;6:373–9.
5. Arinaga S, Karimine N, Takamuku K, et al. Enhanced induction of lymphokine activated killer cell after lentinan administration in patients with gastric carcinoma. Int J Immunopharmacol 1992;14:535–9.
6. Matsuoka H, Yano K, Seo Y, et al. Usefulness of lymphocyte subset change as an indicator for predicting survival time and effectiveness of treatment with the immunopotentiator lentinan. Anticancer Res 1995;15:2291–6.
7. Matsuoka H, Seo Y, Wakasugi H, et al. Lentinan potentiates immunity and prolongs the survival time of some patients. Anticancer Res 1997;17:2751–6.
8. Miyakoshi H, Aoki T, Mizukoshi M. Acting mechanism of lentinan in human—II. Enhancement of non-specific cell-mediated cytotoxicity as an interferon inducer. Int J Immunopharmacol 1984;6:373–9.
9. Arinaga S, Karimine N, Takamuku K, et al. Enhanced induction of lymphokine activated killer cell after lentinan administration in patients with gastric carcinoma. Int J Immunopharmacol 1992;14:535–9.
10. Matsuoka H, Yano K, Seo Y, et al. Usefulness of lymphocyte subset change as an indicator for predicting survival time and effectiveness of treatment with the immunopotentiator lentinan. Anticancer Res 1995;15:2291–6.
11. Matsuoka H, Seo Y, Wakasugi H, et al. Lentinan potentiates immunity and prolongs the survival time of some patients. Anticancer Res 1997;17:2751–6.
12. Tari K, Satake I, Nakagomi K, et al. Effect of lentinan for advanced prostate carcinoma. Hinyokika Kiyo (Acta Urol Japon) 1994;40:119–23 [in Japanese].
13. Jones K. Shiitake: A major medicinal mushroom. Alt Compl Ther 1998;4:53–9 [review].
14. Taguchi I. Clinical efficacy of lentinan on patients with stomach cancer: End point results of a four-year follow-up survey. Cancer Detect Prevent Suppl 1987;1:333–49.
15. Matsuoka H, Seo Y, Wakasugi H, et al. Lentinan potentiates immunity and prolongs survival time of some patients. Anticancer Res 1997;17:2751–6.
16. Hobbs C. Medicinal Mushrooms. Santa Cruz, CA: Botanica Press, 1995, 125–8.
17. Guangwen Y, Jianbin Y, Dongqin L, et al. Immunomodulatory and therapeutic effects of lentinan in treating condyloma acuminata. CJIM 1999;5:190–2.
18. Hobbs C. Medicinal Mushrooms. Santa Cruz, CA: Botanica Press, 1995, 125–8.
19. Gordon M, Guralnik M, Kaneko Y, et al. A phase II controlled study of a combination of the immune modulator, lentinan, with didanosine (ddI) in HIV patients with CD4 cells of 200–500/mm3. J Med 1995;26:193–207.
20. Threlkeld DS, ed. News, Keeping Up, December 1994, Lentinan. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Dec 1997, 805.
Last Review: 11-07-2012
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The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2013.