The Healing Power of Mushrooms

Shiitakes, matsutakes, maitakes, and other friendly fungi could fight cancer, cholesterol, and HIV Dawn in Telluride, Colorado, is chilly, even in the dog days of August. But the cold doesn't matter. I'm up to go mushroom hunting, and my excitement is more than the morning can cool. It's my first time heading into the woods to gather wild mushrooms, especially ones I plan to eat. But I'm not here to set off on a vision quest or become a kidney transplant candidate. It's the 18th annual Telluride Mushroom Festival, and guiding my initiation into the world of mycology are a couple hundred biologists, nature photographers, and amateur mushroom fans from around the country. They've come for the weekend to see old friends, swap mushroom news, and enjoy Rocky Mountain earth flavors packaged in the bright orange folds of chanterelles and the musky aroma of matsutakes. The festival is more than foraging through mountain meadows for fungal delights. It hosts a series of workshops on the interplay between mushrooms and human beings. One of the most popular is on medicinal mushrooms, the bridge between natural healing and gourmet cooking. “The line between gourmet and medicinal mushrooms has blurred,” says Paul Stamets, author of several books on mushroom cultivation and one of the pillars of the festival. “All gourmet mushrooms have medicinal benefits.” In Asian cuisine, mushrooms are prized as much for their medicinal benefits as for their taste or texture. This contrasts with the American or Western approach to food; only recently has science confirmed that eating vegetables indeed prevents disease. The fact is that many wild mushrooms from around the world, including North America, contain potent compounds for treating cancer, diabetes, high cholesterol, high blood pressure, and even HIV. Likewise, the biological niche occupied by mushrooms puts them in competition with bacteria, resulting in strong antibiotic defenses that have yet to be fully understood. According to Stamets, pharmaceutical companies have largely ignored these compounds, perceiving mushrooms as foods, and have left the research to scientists in Asia and Europe. The result is a paucity of American studies but an abundance of reports from scientific communities overseas. The potency of these chemicals cannot be ignored. In the November 1996 issue of Nutritional Review, Dr. Raymond Chang of Memorial Sloan-Kettering Cancer Center in New York wrote: “It is estimated that approximately 50 percent of the annual 5 million metric tons of cultivated edible mushrooms contain functional nutraceutical or medicinal properties.” Perhaps the most studied mushroom is the maitake, or hen of the woods, which resembles a ball of deep shag carpeting. Compounds in maitake called beta-glucans were shown in a 1989 Japanese study to stimulate immune systems in animals to kill cancer cells, stop tumor growth, and accelerate production of natural killer cells. When cancer cells were grown in vitro, the maitake beta-glucans didn't work, but rather were most effective as a catalyst for getting the immune system into high gear. Another 1989 study found that maitake mushrooms, fed to hypertensive rats for eight weeks, reduced high blood pressure. A 1994 study reported success feeding powdered maitake mushrooms to diabetic mice to reduce their blood glucose levels. In 1993, Japanese researchers reported that beta-glucan extracted from maitakes inhibited HIV and restrained breast cancer; they suggested that maitake extracts be used with other AIDS drugs. Broad-capped shiitake mushrooms, another variety familiar to chefs and medical researchers alike, were first recognized as a potential weapon against HIV in Japan in the mid-'80s but did not gain recognition here for almost 10 years. One compound, lentinan, a kind of beta-glucan extracted from shiitakes, has been used by Japanese oncologists for over 20 years to stem the growth of malignant tumors. This same compound got star billing at the Sixth International Conference on AIDS in 1990, when published reports showed lentinan's ability to increase immune system cells. Since then, lentinan has been approved in Japan as a cancer treatment and is being studied in the United States for HIV treatment. Reishi mushrooms, known as Ganoderma lucidum or varnished wood conch, are best reserved for making tea, according to the experts, but are no less potent a medicine than the other two. They're often used in a traditional Chinese medicinal preparation called ling zhi—also the name researchers gave to a protein extracted from the mushroom in a 1995 study documenting its ability to keep the immune system from attacking transplanted tissues. Another 1995 study demonstrated how Ganoderma extracts protected the liver and actively scavenged for free radicals. In 1997 the International Journal of Cancer published a study on the anti-tumor and immune-modulating effects of Ganoderma lucidum. As with the maitake research, extracts of the mushroom stimulated the system to produce a host of defenses and induced apoptosis, or “cell suicide,” among cancer cells. These three mushrooms represent just a sampling of the wide variety of medicinal mushrooms out there. Oyster mushrooms, matsutake, wood ear—varieties you’ll see in upscale grocery stores and on restaurant menus—are also in labs proving their potential for healing. But this is all old hat for the mycophiles—mushroom lovers—at the Telluride Mushroom Festival. They know mushrooms are powerful gifts of nature and are busy picking them by the bushel to send to the festival kitchen, which produces a spectacular array of dishes: roasted matsutakes, hedgehog mushroom stew, penne with shrimp russulas, and, of course, the talk of the festival, Rita’s Famous Chanterelle Strudel. At festival’s end, chatter about medicinals and immunomodulation subsides in favor of a glass of wine and a sampling of the mushroom spread and crostini. “There are a lot more people this year,” says one veteran reveler. “I guess more people are getting turned on to mushrooms.” From Shambhala Sun (Jan. 1999). Subscriptions: $24/yr. (6 issues) from 1345 Spruce St., Boulder, CO 80302-4886.