Maitake mushrooms, considered gourmet food in this country, have been used for thousands of years as medicines in Asian cultures, especially in Japan. Recent research has discovered this ancient natural medicine can be very beneficial in protecting against and fighting many types of cancer including breast cancer. Maitake mushrooms boosts and stimulates the immune system. The immune system is our primary defense against most diseases. These mushrooms have also been found to stop tumor cells from growing, causes tumors to shrink, and prevents them from spreading to other areas of the body.

In a clinical study, breast cancer patients (stage 2 to stage 4) were given whole maitake powder or something called the "D fraction" of maitake mushrooms. The D fraction of the mushrooms contains polysaccharides or a type of sugar that is thought to be responsible for most of the mushroom's medicinal effects. Tumors shrank and symptoms improved in 68.8% of the patients.

Maitake mushrooms are also beneficial for patients taking chemotherapy. Chemotherapy weakens the immune system. Maitake mushrooms will counteract this effect by helping to keep the immune system strong.