Copper is another trace mineral that many think may be helpful in reducing the symptoms of rheumatoid arthritis. Copper is necessary for the activity of an enzyme involved the health of connective tissue; connective tissue provides flexibility in blood vessels, bones and joints.

Crimini, brown button, portabello and shiitake are good sources of iron, which is primarily used as part of hemoglobin, the portion of the red blood cells responsible for transporting and releasing oxygen throughout the body. Hemoglobin synthesis also relies on copper, a nutrient found in mushrooms.

Many mushrooms are good sources of riboflavin, pantothenic acid and niacin, as well as a very good source of thiamin, vitamin B6 and vitamin B12, and folate. Riboflavin (vitamin B2) helps the body to process energy properly. Pantothenic acid helps the body to deal with physical stress and fatigue. Niacin is thought to be helpful in reducing cholesterol levels and in preventing osteoarthritis, and vitamins B12 and B6 are both needed to convert homocysteine, a substance that can directly damage blood vessel walls, into nonthreatening substances. At high levels, homocysteine is associated with a greatly increased risk for heart attack and stroke. An eight-ounce serving (one cup) of crimini, white and brown and oyster mushrooms contains 61% of the daily value for niacin, 10% of the DV for vitamin B12, and 18 % of the DV for vitamin B6.

Mushrooms are also an excellent source of zinc. Zinc is an important component of a healthy immune system A strong immune system depends on adequate zinc levels, so the zinc in mushrooms may also help to prevent illnesses such as recurrent colds and ear infections. An eight-ounce serving of crimini, portabello, button or shiitake mushrooms provide 20% of the daily value for zinc.