Studies in animals have found antitumor, cholesterol-lowering, and virus-inhibiting effects in compounds in shiitake mushrooms. However, clinical studies are needed to determine whether these properties can help people with cancer and other diseases. It is reasonable to include shiitake mushrooms as part of a balanced diet.
Shiitake mushrooms are promoted to fight the development and progression of cancer and AIDS by boosting the body's immune system. These mushrooms are also said to help prevent heart disease by lowering cholesterol levels and to help treat infections such as hepatitis by producing interferon, a group of natural proteins that stops viruses from multiplying. Promoters claim that eating both the cap and stem of the mushroom may be helpful, but they do not say how much must be eaten to have an effect. They say the strength and effects of the mushroom depend on how it is prepared and consumed.
Promoters claim that shiitake mushrooms contain several compounds with health benefits. A compound called lentinan is believed to stop or slow tumor growth. Another component, activated hexose-containing compound (also known as 1,3-beta glucan), is also said to reduce tumor activity and lessen the side effects of cancer treatment. The mushrooms also contain the compound eritadenine, which is thought to lower cholesterol by blocking the way cholesterol is absorbed into the bloodstream. These claims are currently being studied.
The fresh or dried whole mushroom is widely available in grocery stores.