Shiitake mushrooms and their extracts
Shiitake mushrooms are native to East Asia but are grown worldwide for their supposed health benefits. They are valued in some cultures as an anti cancer agent. The fresh and dried forms of the mushroom are commonly used in East Asian cooking. Extracts from the mushroom, and sometimes the whole dried mushroom, are used in herbal remedies.
One shiitake extract called lentinan is a beta glucan. This is a type of complex sugar compound. Beta glucan is believed to stimulate the immune system and trigger certain cells and proteins in the body to attack cancer cells. In laboratory studies, it seems to slow the growth of some cancer cells.
In mice, lentinan has been shown to stop bowel cancer cells growing. In laboratory tests, the protein part of lentinan (lentin) can stop some fungal cells growing. It can also stop leukaemia cells dividing.
Some Japanese researchers give lentinan along with chemotherapy to treat patients with lung, nose, throat, and stomach cancers. A recent clinical trial didn’t show that it helped to treat prostate cancer. Some doctors in Japan use another shiitake extract called eritadenine.