Breast cancer. Those two words strike fear into the heart of just about any woman—and with good reason. According to the American Cancer Society, nearly 290,000 new cases of breast cancer will be diagnosed in the US in 2011. Such statistics can leave us feeling that it is only a matter of time before breast cancer affects us or someone we love.

So when I attended the recent Integrative Healthcare Symposium in New York City and met Cynthia Bye, ND, a naturopathic doctor based in Vancouver, Washington, I was intrigued to hear that she often prescribes mushroom extracts for patients who want to be proactive in improving their immune function and reducing their cancer risk. And in fact, a growing body of research suggests that certain mushrooms are powerful weapons in the fight against breast cancer and other cancers. For instance, various mushrooms…

  • Contain chemicals (including conjugated linoleic acid) that act as aromatase inhibitors. Aromatase is an enzyme in fat tissue that converts testosterone to estrogen. Since estrogen fuels many breast tumors, certain mushrooms combat breast cancer by suppressing aromatase activity.
  • Increase apoptosis, the natural programmed death of old, worn-out cells. This acts as a check against the cells becoming cancerous (since cancer cells proliferate instead of undergoing apoptosis).
  • Stimulate the immune response through the action of beta glucans, substances that support the production and/or function of various disease-fighting cells, including white blood cells, T-cells and natural killer cells.

Simply eating more mushrooms may be good for you—but for maximum therapeutic effects, consider mushroom extracts. Reason: The beta glucans are in the mushrooms’ cell walls, which you cannot digest. To get the beta glucans, Dr. Bye said, you need mushroom supplements prepared through a process called hot water extraction.

Dr. Bye recommended using mushroom extracts only under the guidance of a naturopathic doctor who is trained in their use, to assure that you receive a formulation specifically tailored to your needs. Mushrooms come in many different varieties—coriolus, crimini, maitake, portobello, reishi, shiitake, white button, etc.—and each has its own distinct health benefits. The extracts best suited to helping a healthy person stay healthy are not the same as those that might be prescribed for a person with compromised immunity… or for a woman at high risk for cancer… or for a woman with a history of breast cancer who wants to reduce the risk for recurrence. Referrals: American Association of Naturopathic Physicians (866-538-2267,