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Shiitake
CautionShiitake · (Lentinula edodes)
Omphalotaceae (Omphalotaceae)
Description
A brown, umbrella-shaped cap with pale scattered scales and a rich, savoury note make shiitake one of the world's most widely cultivated edible mushrooms; fruiting bodies are harvested nearly year-round depending on climate, here mainly from January to April and September to December. Characteristic constituents include the polysaccharide lentinan, further beta-glucans, the sulphur-containing aroma compound lenthionine, eritadenine, and ergosterol as provitamin D2 alongside several B vitamins. Traditionally, shiitake is valued raw as a nourishing food, brewed as tea for digestive complaints, and historically described as supportive for elevated cholesterol as well as an adjunct in cancer therapy. Important: eaten raw or undercooked, the mushroom can trigger the rare, itchy shiitake dermatitis, since the heat-sensitive constituent lentinan only breaks down on thorough cooking; always cook thoroughly. Seek medical advice before use if taking immunosuppressants or anticoagulants, or during pregnancy and breastfeeding.
Dried fruiting-body powder or extracts (also as capsules) are traditionally taken for general strengthening and immune support; the polysaccharide lentinan is regarded as immunomodulating.
A decoction of the dried fruiting bodies is used in East Asian folk medicine for stomach complaints and general invigoration.
Sources: [1]
Shiitake contains eritadenine, an amino acid credited with cholesterol-lowering effects; the mushroom is traditionally eaten to support cardiovascular health.
Lentinan derived from shiitake is approved in China and Japan as an adjunct to chemotherapy; randomized clinical evidence is mixed (positive earlier trials and meta-analyses, but a large phase III trial missed its primary endpoint). Not for self-treatment of cancer.
Eaten raw or undercooked, shiitake can trigger the rare 'shiitake dermatitis' (a whip-like, itchy rash) linked to the polysaccharide lentinan; cook thoroughly. Inhaling larger amounts of spores — an issue for growers, not for the kitchen — has been linked to cases of hypersensitivity pneumonitis. The mushroom contains haemagglutinating lectins that are destroyed by cooking. Allergic reactions are possible. Lentinan may affect immune and clotting-related processes; seek medical advice when taking immunosuppressants or anticoagulants and during pregnancy/breastfeeding.
Unproblematic as a thoroughly cooked edible mushroom in food amounts. Concentrated extracts and lentinan preparations have not been studied in pregnant women and do not belong there.
Customary as a food. There are no data on extracts during breastfeeding.
Harmless as a thoroughly cooked edible mushroom — expressly not raw, because of shiitake dermatitis. Extracts have not been studied in children.
Drug interactions
Immunsuppressiva
The polysaccharide lentinan stimulates the immune system and can counteract a deliberate suppression of it. This concerns extracts, not the mushroom in food.
Gerinnungshemmer und Thrombozytenhemmer
An additive effect on blood clotting is discussed for shiitake extracts. With such medication and regular use of preparations, clear it medically.
Harvested part: fruiting body
- Time of day:
- Harvest when the cap has opened but the edge is still slightly curled under — the flesh is then firm and the flavour strongest. Fully flat caps have already dropped their spores. Twist them off at the base of the stem rather than tearing.
- Drying:
- Dry gills upwards at 45 to 50 degrees. Laying them in the sun gills upwards for an hour or two beforehand markedly increases the vitamin D2 content: the ergosterol they contain is converted by UV-B light. Dried shiitake taste stronger than fresh — use the soaking water too.
- Storage:
- 24 months — Dried, keep airtight, dark and dry. Fresh, they keep about a week in a paper bag in the fridge; in plastic they turn slimy.
- Lentinan (Beta-1,3-Glucan)Polysaccharide
Immunomodulating beta-glucan polysaccharide, the main compound in medicinal research.
- Beta-GlucanePolysaccharide
Cell-wall polysaccharides with immune-activating activity.
- EritadenineOther
Amino-acid derivative credited with cholesterol-lowering activity.
- LenthioninOther
Cyclic sulfur compound responsible for the characteristic aroma.
- Ergosterol (Provitamin D2)Other
Converts to vitamin D2 upon UVB exposure.
- B-Vitamine (B3, B5, B6)Vitamin
Abundant in the fruiting bodies.
- [3]MonographLentinan: progress in inflammatory diseases and tumor diseases (Eur J Med Res, PMC10763102)(accessed: 2026-05-31)
- [4]MonographLentinan prolonged survival in patients with gastric cancer receiving S-1-based chemotherapy (PMC3191325)(accessed: 2026-05-31)
- [5]MonographTherapeutic values and nutraceutical properties of shiitake mushroom (Lentinula edodes): A review(accessed: 2026-05-31)
- [7]MonographShiitake Mushroom — About Herbs, Memorial Sloan Kettering Cancer Center(accessed: 2026-08-22)
- [1]WikipediaShiitake — Wikipedia (Deutsch)(accessed: 2026-05-31)
- [2]WikipediaShiitake — Wikipedia (English)(accessed: 2026-05-31)
- [6]CommonsFile:Lentinula edodes shiitake.JPG — Wikimedia Commons(accessed: 2026-05-31)