The Properties of Mushrooms

Mushrooms, fungi that grow from microscopic spores, have been an important part of the human diet since ancient Egypt, but they didn't become popular in the United States until the 1800s. Nearly 40,000 types of mushrooms exist, including well-known grocery varieties such as the button, crimini, portobello and shiitake. Since wild varieties can be toxic, you should buy mushrooms from retailers. Store mushrooms in paper bags and keep in the refrigerator to prevent spoiling; use them within five days of purchase.

Physical Properties

• Most mushrooms have two basic components: Stipes, or stalks, make up the mushroom's body, and the pileus, or cap, is the mushroom's spore-releasing fruit body. The stipe and pileus are both made of hyphae, the tightly woven fibers that give mushrooms their dense, meaty texture. Mushrooms have no roots or seeds, and they're absorbent like sponges, drinking up water or other liquids surrounding them.

Nutrient Properties

• Mushrooms are a low-calorie food, with just 100 calories per oz. They're relatively high in fiber and iron, with 1/2 cup providing almost 10 percent of the federally recommended daily allowance for both nutrients. Mushrooms are a source of the B vitamins riboflavin and niacin and the antioxidant selenium, and they contain polysaccharides, healthful sugar compounds that protect against cardiovascular disease. Mushrooms also contain the minerals copper and potassium; in fact, an average portobello mushroom contains more potassium than a banana.

Health Properties

• Because of their nutrient profile, many mushrooms have medicinal properties. The U.S. Department of Agriculture found, in 2010, that button mushrooms, which make up 90 percent of the mushrooms eaten in America, boost the activity of key immune cells, increasing antiviral proteins and compounds that repair damaged tissue. Additional research from the USDA reveals that mushrooms' minerals help the body make red blood cells, maintain heart rhythm and promote muscle and nerve function. Mushrooms retain most of their nutrients during cooking.

Psychoactive Properties

• Many wild mushrooms contain psilocybin or psylocin, hallucinogenic compounds that can cause heightened perception, euphoria, nausea, anxiety and paranoia. In people with a history of mental illness, hallucinogenic mushrooms can cause panic attacks or other acute psychological problems. Mushrooms' negative side effects are stronger in patients taking antidepressants.