Your Health: Mushrooms offer more than good taste

For folks who savor the flavor and texture of mushrooms, here’s another good reason to enjoy them: certain varieties are known to offer significant health benefits.

Recent research suggests that the Shiitake mushroom, in particular, can help ward off a number of disorders and diseases, ranging from the common cold to cancer.

For thousands of years, the Shiitake has served as both a culinary ingredient and a medicinal agent in Asia. Chinese healers have long used the mushroom as a tonic to prevent premature aging and as a remedy for respiratory tract infections, liver disease and poor circulation.

Over the past two decades, the Shiitake has become an increasingly popular ingredient in American cuisine. The large, umbrella-shaped fungus is valued for its full-bodied flavor, rich color and meaty texture.

Recently, pills and powders containing extracts of the mushroom have been popping up in the United States. A growing body of scientific evidence suggests that specific compounds in the fungi have potent anti-cancer properties.

Mushrooms appear to fight cancer in several ways. For starters, they’re rich in disease-fighting antioxidants. Researchers at Penn State University concluded that in terms of dietary antioxidant content, several mushroom varieties are comparable to green beans, red peppers and broccoli.

Some scientists believe that compounds in mushroom extracts, including lentinan, prevent tumor growth by increasing the disease-fighting activity of the immune system, rather than by killing cancer cells directly. Lentinan stimulates the production of tumor necrosis factor and interleukins, substances that play critical roles in the destruction of tumor cells.

Other ingredients in the Shiitake appear to inhibit the proliferation of new blood vessels that are necessary to support the growth of cancerous tumors.

In Japan, extracts of the mushroom are routinely administered to cancer patients to bolster immunity and to reduce the unwelcome side effects of cancer treatment. The results of several clinical trials revealed that Shiitake extracts can shrink tumor size and prolong life in cancer patients receiving chemotherapy.

In addition to its promising role in cancer treatment and prevention, the Shiitake may also be useful in reducing the risk of cardiovascular disease. In animal and human studies, extracts of the fungus have been shown to effectively lower blood pressure.

At least one compound found in the mushroom helps block the absorption of dietary fats in the body, reducing blood levels of cholesterol and triglycerides. Researchers in Japan recently reported that the mushroom may help prevent atherosclerosis, also known as hardening of the arteries.

Blood vessels of animals treated with Shiitake extract were found to have significant reductions in cholesterol-containing plaques. Compounds in the mushroom also appear to have significant anti-clotting effects, which could offer additional protection against heart attacks.

Preliminary research suggests that the Shiitake may provide a number of benefits in the treatment of common viral infections, including influenza, hepatitis and AIDS. Extracts of the mushroom have been shown to trigger the production of interferon and other natural proteins that prevent viruses from multiplying in the body.

In spite of being a low-calorie food, it’s packed with key vitamins and minerals. As a good source of protein, it serves as a useful meat substitute in vegetarian dishes.

Unlike certain vegetables, cooking appears to improve the Shiitake’s nutritional value. The results of a study published in the scientific journal Food Chemistry demonstrated that heating the mushroom actually enhances its overall antioxidant activity.

Shiitake and dietary supplements containing Shiitake extracts are generally considered to be safe and nontoxic. For some susceptible people, however, consuming the fungi can cause stomach upset and can occasionally lead to allergic reactions involving the skin and the respiratory system.

Individuals suffering from gout or kidney stones should consume the mushrooms in moderation. There’s some evidence that excessive consumption of Shiitake can trigger flare-ups of both conditions.

If you enjoy the flavor and texture of Shiitake, you’ll probably be able to find a good selection at your local supermarket. It’s best to choose fresh, clean mushrooms that are firm and plump and avoid those that are wrinkled, wet or slimy.

If you’re not a fan of the flavor or texture, but you still want all the health benefits that the Shiitake has to offer, you can find extracts of the mushroom in capsules and powders at many health-food stores and herb shops.

Rallie McAllister is a board-certified family physician, speaker and the author of several books, including “Healthy Lunchbox: The Working Mom’s Guide to Keeping You and Your Kids Trim.” Her website is www.rallieonhealth.com.Copyright 2008 Creators Syndicate Inc.