Mushrooms may not seem like a big health deal—most people think of them simply as earthy additions to meals and salads. What most people don’t realize: Dozens of varieties of mushrooms are medicinal. Rich in unique carbohydrates (polysaccharides) called beta glucans, they can energize the body’s disease-fighting immune cells.

Here’s what you need to know about three effective medicinal mushrooms…

Note: Mushroom supplements generally are safe, but because they activate the immune system, they should not be taken by organ-transplant recipients on ­immunosuppressive drugs. Also, look for a hot-water (or hot-water/ethanol) extract. This may be stated on the supplement label—if not, check the company’s website. I typically recommend that ­patients take one mushroom supplement at a time, rather than two or three.

MAITAKE

I consider the maitake mushroom (Grifola frondosa)—native to northern Japan and called the “King of Mushrooms” throughout Asia—to be one of the most powerful allies in the battle against cancer. It can be used for immune enhancement in addition to conventional cancer treatment.

Compelling research: Chinese doctors studied more than 300 people with bladder cancer after they had surgery for the disease, tracking the effectiveness of five standard and natural therapies, including supplements of a maitake mushroom extract. After an average of seven years, those taking maitake had the lowest rate of cancer recurrence (35%). And in a study of 36 cancer patients published in Alternative Medicine Review, maitake supplements improved symptoms and decreased the size of tumors in 69% of breast cancer patients, 63% of lung cancer patients and 58% of liver cancer patients. The supplements also boosted the cancer-killing power of chemotherapy by up to 40%—doses ranged between 50 milligrams (mg) to 150 mg daily (some patients received chemotherapy and some did not).

Decades of research from Japan show that one “fraction” or extract of ­maitake—the D-fraction—is most effective in boosting the immune system and fighting cancer. Specifically, D-fraction boosts the number and power of natural killer cells, immune cells that can “recognize” and kill cancer cells and viruses.

Best product and dose: For my patients with cancer, I often prescribe the over-the-counter product MaitakeGold 404, used in many studies on cancer. I prescribe a daily dose of 0.5 mg to 1 mg per kilogram (2.2 pounds) of body weight. For everyday immune-strengthening, I often recommend 5 mg to 15 mg daily taken 20 minutes before meals or on an empty stomach.

You can find maitake mushrooms in your supermarket, farmers’ market or gourmet market—and add them to your diet to help prevent cancer. The mature mushroom—also called “Hen of the Woods”—has large, fleshy grayish-brown caps. Cut off the tough white base, then slice and sauté the caps for 10 to 15 minutes with salt, pepper and garlic. They’re great in pasta, risotto, eggs and other dishes. I recommend two to three servings of maitake mushrooms weekly.

TURKEY TAIL

The turkey tail mushroom (Trametes versicolor) grows around the world and has a fan-shaped, brown-and-tan cap that resembles turkey feathers. Used for centuries in folk and traditional medicines in China and Japan, this mushroom can treat lung infections, hepatitis (liver infection) and cancer. Modern medicine has focused on cancer.

Compelling research: More than 400 studies show that turkey tail can fight cancer. Nearly all the studies on people have been with PSK (krestin), a proprietary extract that has been used as a supportive therapy by thousands of cancer patients in Japan. In one study published in Anticancer Research, Stage 1 and 2 lung cancer patients taking the extract had a five-year survival rate of 39%, compared with 16% for patients taking a placebo. Other studies show higher survival rates in people taking PSK for colorectal, esophageal and ­stomach ­cancers.

Best product and dose: For those with cancer, I often recommend 1,000 mg to 1,500 mg, twice daily, taken in the morning and evening on an empty stomach. Look for a product that has 20% beta glucans. As for your diet—turkey tail is not an appetizing mushroom.

REISHI

Reishi (Ganoderma lucidum)—a shiny fan-shaped mushroom with colors ranging from reddish brown to black—has been used for thousands of years by traditional healers in Japan and China. (Chinese healers call this the “Mushroom of Immortality.”) Among mushrooms, it’s your best choice for an everyday tonic to boost the strength of your immune system. And it also strengthens the rest of the body. Proven benefits include…

Reversing fatty liver disease. Fatty liver afflicts an estimated 25% of Americans and can lead to liver disease and liver cancer. In a new study published in Pharmaceutical Biology, the livers of people with fatty liver completely normalized after they took reishi for six months. And their levels of cell-damaging oxidants fell by 42%. The participants made no other changes in diet, exercise or anything else.

Improvement in fibromyalgia. In a recent study by Spanish researchers published in Nutrición Hospitalaria, people with the pain, stiffness and poor fitness typical of fibromyalgia saw improvements in flexibility, strength and endurance after taking reishi for six weeks.

Eliminating oral HPV virus. Oral infection with some strains of human papillomavirus (HPV) can cause throat cancer. In a study of 61 people with cancer-causing oral HPV, published in International Journal of Medicinal Mushrooms, 88% of people who took reishi for two months had complete clearance of the virus.

Easing rheumatoid arthritis pain. In a study of people with rheumatoid arthritis published in Arthritis & Rheumatism, people who took reishi had less inflammation and pain compared with those taking a placebo.

Raising HDL “good” cholesterol in people with diabetes. In a study published in British Journal of Nutrition, people with diabetes who took reishi had an increase in “good” HDL cholesterol.

Preventing altitude sickness. Reishi is a favorite natural remedy of travelers and trekkers to prevent altitude sickness. Start taking the supplement 10 to 14 days before you travel to a higher altitude.

Best product and dose: Look for an extract product containing a minimum of 10% polysaccharides (beta glucans) and 4% triterpene (another active ingredient). Take 800 mg two to three times daily.

Reishi is bitter and woody-tasting and not ideal for culinary use.