Your question is well timed. I just learned of the exciting results of a seven-year study funded by the National Institutes of Health of the use of turkey tail mushroom (Trametes versicolor) to boost immunity in women who had been treated for breast cancer. (The mushroom's name comes from its unique shape and colors, which make it resemble a wild turkey's tail.) Researchers at the University of Minnesota and Bastyr University conducted the study in women with stages I-III breast cancer who had completed radiation therapy or chemotherapy. Results showed that immune function was enhanced in the women who took daily doses of turkey tail in pill form. (The actual product used in the study was Host Defense Turkey Tail mushroom from Fungi Perfecti.) The researchers reported that the improved immune response was dose dependent and that none of the subjects suffered any adverse effects. The findings were reported in November, 2010, at the International Conference of the Society of Integrative Oncology in New York.
We don't know exactly how the turkey tail mushroom product used in this trial worked to boost immunity. Paul Stamets, director of research and founder of Fungi Perfecti, said that one theory holds that the mushroom improves the ability of the immune system's natural killer cells to attack cancer cells. The next phase of this ongoing study will be to evaluate the effects of this improved immunity on patient survival.
The findings so far are very good news, just what physicians who treat cancer have been looking for - a non-toxic therapy to boost immune function, which is typically depressed by chemotherapy and radiation therapy. I have long recommended medicinal mushrooms to strengthen the body's defenses in persons with cancer.
Three other mushroom species, maitake, reishi and Agaricus blazei, are known for their immune-enhancing and anti-cancer effects. Maitake (Grifola frondosa) is an edible mushroom known in the United States as "hen of the woods" because it resembles the fluffed tail feathers of a nesting hen. In addition to its anti-cancer, anti-viral and immune-enhancing properties, maitake may also reduce blood pressure and blood sugar. Reishi (Ganoderma lucidum), too bitter and woody to eat as food, is widely available in tea bags, capsules and as liquid extracts. Animal studies have shown that reishi improves immune function and inhibits the growth of some malignant tumors; it is also a natural anti-inflammatory agent. Agaricus blazei contains beta glucans, a group of polysaccharides (complex sugars) believed to be the compounds responsible for its immune-boosting effects. Research has also shown that Agaricus blazei has anti-tumor and anti-viral activity, as well as moderating effects on blood sugar and cholesterol.
Andrew Weil, M.D.