Shiitake
Shiitake (Lentinula edodes) is one of the most widely grown mushrooms in the world, eaten as food and sold as extracts. Half a cup cooked gives about 650 µg of copper, 72% of the US Daily Value; the claims about immunity rest on small studies.
No set daily amount
650 µg of copper in half a cup of cooked shiitake pieces
72% of the US Daily Value for copper
- In food Fresh or dried a common cooking mushroom
- In supplements Extracts, AHCC mostly from mycelium
- Studied compound Lentinan a beta-glucan
- Main risk Skin rash from raw or undercooked caps
Copper figure from the NIH Office of Dietary Supplements. The food library has no shiitake entry yet, so no per 100 g ranking.
Shiitake as Food and as a Supplement
Unlike most mushrooms sold as extracts, shiitake is an everyday food, so most people get it from cooking.
- Fresh shiitakehalf a cup of cooked pieces has about 650 µg of copper; the stems are tough and usually removed
- Dried shiitakesoaked before use, with a stronger savory taste; the soaking water is used as broth
- Supplementsshiitake powder, extracts of its mycelium, and AHCC, a product made from cultured mushroom mycelium that includes shiitake; contents vary by brand
What Is Shiitake?
Shiitake grows naturally on fallen hardwood in East Asia, and the name comes from shii, a Japanese tree it grows on, and take, mushroom. Today it is farmed on logs or blocks of sawdust. The caps are brown and umbrella-shaped with white gills.
Shiitake Nutrition: Copper and Vitamin D
As a food, shiitake is low in calories and gives fiber and B vitamins, and its standout nutrient is copper: half a cup of cooked pieces has about 650 µg, close to three quarters of the US Daily Value of 900 µg. In the NIH table of copper foods it sits next to potatoes and cashews.
Like other mushrooms, shiitake makes vitamin D2 when ultraviolet light hits it, the way skin makes vitamin D in sunlight. Mushrooms grown in the dark have little. The NIH lists UV-treated mushrooms among the few plant sources of vitamin D.
Lentinan and Shiitake Immune Studies
Lentinan is a beta-glucan, a long chain of glucose, purified from shiitake. In Japan it has been given by injection into a vein alongside chemotherapy, mainly for stomach cancer, and some trials found longer survival when it was added. Eating shiitake is not the same as an injection of purified lentinan, so those results say nothing about shiitake as food.
For food, the best human data is a 4-week trial in 52 healthy young adults who ate cooked shiitake every day. Some immune cell counts and antibody levels in saliva changed, but the study did not measure whether people caught fewer infections.
Shiitake Dermatitis
Shiitake dermatitis is an itchy rash of long red streaks, as if the skin had been whipped, that appears a day or two after eating raw or undercooked shiitake. It is linked to lentinan, which heat breaks down, and it fades over days to weeks. Cooking shiitake through prevents it. Some people who handle shiitake at work also develop allergies to its spores.
Sources are listed at the end of this page. Not medical advice.
Tracking Shiitake in Caltide
- Logged as foodLog the shiitake you cook as mushrooms and Caltide adds its calories, copper, and other nutrients to your day in the Nutrition tab.
- Extracts not totaled yetCaltide does not add up lentinan or other shiitake compounds from supplements yet.
Shiitake Sources and References
The figures and claims on this page are checked against these sources.
- NIH Office of Dietary Supplements: Copper, Health Professional Fact Sheet
- NIH Office of Dietary Supplements: Vitamin D, Health Professional Fact Sheet
- Dai et al. (2015): Consuming Lentinula edodes (Shiitake) mushrooms daily improves human immunity, a randomized dietary intervention in healthy young adults
- NIH National Cancer Institute: Medicinal Mushrooms (PDQ), Health Professional Version
- USDA FoodData Central
Questions About Shiitake
As a food, yes: it is low in calories and a good source of copper, with about 650 µg in half a cup of cooked pieces, 72% of the US Daily Value. Claims beyond that, such as for immunity, rest on small studies.
Only a little unless it has been exposed to ultraviolet light. Mushrooms exposed to sunlight or UV lamps make vitamin D2, and the NIH lists UV-treated mushrooms among the few plant sources of vitamin D.
An itchy rash of long, whip-like red streaks that can appear a day or two after eating raw or undercooked shiitake. It is linked to lentinan, clears up over days to weeks, and is avoided by cooking the mushrooms well.
Lentinan is a beta-glucan, a long sugar chain, from shiitake. In Japan a purified form is given by injection alongside chemotherapy for some cancers; eating shiitake is not the same treatment.
It is not shown. In a 4-week trial in 52 healthy young adults, eating shiitake daily changed some immune cell measures, but the study did not test whether people got sick less often.
Yes. They include shiitake powder, extracts of its mycelium, and AHCC, a product made from cultured mushroom mycelium that includes shiitake. Their contents vary, and human evidence for them is limited.
Mushrooms you log as food count toward your calories, copper, and other nutrients. Caltide does not total lentinan or other shiitake compounds.
Track anywhere. On any device.
Your calorie counter and food diary in your pocket, free and without ads, with Tide one tap away.
- Log by photo, barcode or voice, right where you eat
- Steps and workouts from Apple Health and Health Connect
- The same log on your phone and in your browser, always in sync