Written by Patrick Massey, M.D., Ph.D. There are more than 300 research papers in Western medical literature detailing the effects of mushroom extracts on cancer.
In the near future, important discoveries in the treatment of cancer may come from one of nature’s most unassuming members: the mushroom.
For centuries, herbalists and healers have attributed robust healing properties to mushrooms. Although some mushrooms are poisonous, many are considered strong medicine by practitioners of culturally based medical systems such as Oriental medicine. Indeed, some mushrooms are traditionally used to treat cancer.
Modern science has been researching the medical properties of mushrooms for more than 30 years. However, only in the past 10 years have the effects of mushroom extracts on various cancers been more clearly defined.
Mushrooms make a variety of big, sugar molecules called polysaccharides. Polysaccharides are simple sugars like glucose and mannose joined end to end, like a paper clip necklace. These molecules are part of cell walls and membranes and play a role in cell-to-cell communication.
We have known for years that specific polysaccharides are powerful stimulators of the immune system. One of the ways our immune system protects us from bacteria, viruses and cancer cells is by recognizing foreign polysaccharides.
Many mushrooms produce a number of polysaccharides that stimulate the immune system. Some of these polysaccharides specifically stimulate those immune cells that are directly involved in recognizing and killing cancer cells. These cells are called “natural killer” or NK cells. Interestingly, those mushrooms used in culturally based medical for the treatment of cancer seem to produce a lot of polysaccharides that specifically activate NK cells.
Mushrooms exhibit other interesting and potentially beneficial properties. In the test tube (in vitro), some mushroom extracts directly kill cancer cells but are harmless to normal cells. There is some data to suggest that the polysaccharides from mushrooms may also help to protect bone marrow from the effects of chemotherapy as well as enhance its cancer-killing effects.
Many of the mushrooms that exhibit immune-system enhancing properties are edible, such as maitake, shiitake and gandoderma. For mushrooms that are not edible, the polysaccharides must be extracted.
Toxicities are very low and the medical research from around the world suggests significant effectiveness. In the Western medical literature, there are more than 300 research papers detailing the effects of mushroom extracts on cancer. It is no accident that the most commonly used chemotherapy agent worldwide comes from a mushroom.
Despite the enthusiasm and positive research, most of the information on mushrooms and cancer come from smaller clinical trials and extrapolation of data from studies on cancer cells in vitro. Larger clinical trials need to be done in order to determine the best types of mushrooms and dosages.
Although I recommend mushrooms for many of my cancer patients, I also caution people to be careful of advertising claims made by manufacturers and distributors. I recommend consulting a physician with formal training in complementary and alternative medicine. Physicians with this expertise can often be found through local hospitals, medical centers and at the Arizona Center for Integrative Medicine website.
Posted November 19, 2008.
