Mushrooms have been used for thousands of years both as food and for medicinal purposes. They are often classified as a vegetable or a herb, but they are actually fungi. While there are over 14,000 mushrooms, only about 3,000 are edible, about 700 have known medicinal properties, and fewer than one percent are recognized as poisonous.

The Pharaohs prized mushrooms as a delicacy, and the Greeks believed that mushrooms provided strength for warriors in battle. The Romans regarded mushrooms as a gift from God and served them only on festive occasions, while the Chinese treasured them as a health food.

Today, mushrooms are enjoyed for their flavor and texture. They can impart their own flavor to food or take on the flavor of other ingredients. Their flavor normally intensifies during cooking, and their texture holds up well to usual cooking methods, including stir-frying and sauteing.

It is popular to add mushrooms to soups, salads, and sandwiches, or to use them as an appetizer. They also add an appealing touch to vegetable-based casseroles and stews. In the US, mushroom extracts are increasingly being used in nutraceutical products and sports drinks.

Mushrooms contain about 80 to 90 percent water, and are very low in calories (only 100 cal/oz). They have very little sodium and fat, and 8 to 10 percent of the dry weight is fiber. Hence, they are an ideal food for persons following a weight management program or a diet for hypertensives.

Mushrooms are an excellent source of potassium, a mineral that helps lower elevated blood pressure and reduces the risk of stroke. One medium portabella mushroom has even more potassium than a banana or a glass of orange juice. One serving of mushrooms also provides about 20 to 40 percent of the daily value of copper, a mineral that has cardioprotective properties.

Mushrooms are a rich source of riboflavin, niacin, and selenium. Selenium is an antioxidant that works with vitamin E to protect cells from the damaging effects of free radicals. Male health professionals who consumed twice the recommended daily intake of selenium cut their risk of prostate cancer by 65 percent. In the Baltimore study on Aging, men with the lowest blood selenium levels were 4 to 5 times more likely to have prostate cancer compared to those with the highest selenium levels.