Mushrooms are valuable health food - low in calories, high in vegetable proteins, chitin, iron, zinc, fiber, essential amino acids, vitamins and minerals. Most mushrooms provide a wealth of protein, fiber, B vitamins, and vitamin C, as well as calcium and other minerals. And at least three species have demonstrated phenomenal healing potential: maitake, shiitake, and reishi. These medicinal mushrooms have been shown to boost heart health, lower the risk of cancer, promote immune function, ward off viruses, bacteria, and fung, reduce inflammation, combat allergie, help balance blood sugar levels, and support the body's detoxification mechanisms. Recent studies have shown shiitake and reishi mushrooms are potential cancer-fighters. Reishi extracts have been shown to stop the growth of cancerous tumors and also produce an antihistamine action which can help to control allergies. Shiitake mushrooms contain a compound called lentinan, which is being used as a cancer treatment in Japan. They are also a good source of riboflavin and niacin and have no fat or cholesterol. A mushroom broth can help nourish and revive anyone suffering from colds and flu. Place 2 cups of sliced mushrooms in a pan and cover with water. Add 1/2 a small onion, chopped. Simmer 1 hour, or until mushrooms have shrunk and water is a rich brown color. Add salt and pepper to taste. Serve or refrigerate for reheating and serving later.