Stimulation of the immune system, +/- cancer and sarcomas (stomach and uterine cancer = controversial), infections, rickets, lower cholesterol, good for the stomach, spleen, lungs, heart, lower blood pressure, expectorant, loss of appetite and weakness, reduces frequent urination, favors the prostate.
Lentinan, a water-soluble polysaccharide (ß-1,3-glucan with ß-1,6 and ß-1,3-glucopyranoside branches) obtained from fungi is approved as a cancer drug in Japan. The activity mode appears to be the activation of killer and helper “T” cells.
Obviously, in addition to the well-known lentinan, numerous anti-cancer drugs are inside Shiitake.
Lentinula edodes contain all 8 essential amino acids in a higher percentage than in milk, eggs, meat, or soy beans. Many vegetarians consume the Shiitake in place of meat, because it is a good source of protein. Shiitake mushrooms have long been noted for their good benefits in traditional Chinese medicine. They were used to cure colds and increase energy. Recently though, studies have proven for the mushrooms to really be as beneficial as they were long perceived to be. They have been shown to have anti-tumor, antibacterial, anti-cholesterol, antiviral, and immune regulating properties. In medicine, it has been used with HIV positive patients. Shiitakes contain a polysaccharide called lentinan which has been shown to help increase T-cell counts and lower lymphocyte counts. The Shiitake has a fairly good record and has only been shown to cause diarrhea and abdominal bloating.
The main flavor compounds, which are also responsible for the rettich-like odor, have been identified as cyclic sulfur compounds: Lenthionine; 1, 2, 4, 5,- and 1, 2, 3, 5-tetrathiane, trithiolane, and the amino acid eritadenine.
The shiitake contains some, pharmacologically interesting active substances, such as: EP3, a glycoprotein that is thought to have immunostimulatory effects. Eritadenine [4-(9-adenyl)-D-erythro-2,3-dihydroxybutyric acid], an amino acid that lowers cholesterol. Shiitake contains 400-700 mg of it per kg dry weight. LEM, a glycoprotein that is believed to have immunostimulatory and antitumor effects. Lentinan, a polysaccharide that is thought to have immunostimulatory and antiviral effects. However, lentinan is suspected of causing shiitake dermatitis. KS-2, a polysaccharide that is thought to have anti-tumor effects against Sarcoma-180 cell lines and Ehrlich carcinoma.
Shiitake also contains vitamins C, B1, B2, B12, D and niacin. Vitamin D concentration is comparatively high at 22-110 µg per 100 g dry weight and can be further increased by sun or UV radiation.
A study of 52 adults suggested that daily consumption of shiitake may have an immune-boosting effect.
In Japan and China, shiitake is found as a medicinal food known as jap. yakuzen – 薬膳, chin. Yàoshàn – 藥膳 / 药膳, like other mushrooms and vegetables a specific use for inflammation, tumors, stomach disorders, headache, dizziness, cirrhosis of the liver and arteriosclerosis. More frequent meals with shiitake are said to alleviate the aforementioned ailments. For this purpose, the mushrooms are boiled, fried or steamed. This is accompanied by boiled rice, sushi or vegetables. The whole thing is seasoned with miso, soy sauce or tomato sauce.