Mushrooms are a fleshy, edible fungus. While many types of mushrooms are toxic and unsafe to eat, mushrooms found in the grocery store, including crimini, button, shiitake, maitake, lobster, oyster and porcini, are not only edible, but provide a variety of essential nutrients. Cooked mushrooms are low in fat, have zero saturated, trans fats and cholesterol and are low in sodium.
Cooked mushrooms are an excellent source of the mineral selenium. The Office of Dietary Supplements reports that selenium protects the body against tissue-damaging free radicals. The recommended daily allowance, RDA, for selenium is 55 micrograms a day for adults. The USDA’s National Nutrient Database reports that grilled Portobello mushrooms have 26.5 micrograms of selenium per serving, nearly half of the daily RDA for an adult. Four cooked shiitake mushrooms contain 17.9 micrograms of selenium, more than a third of the RDA. A 2010 article in the journal “Nutrition and Metabolism” showed that high blood levels of selenium is associated with a lower occurrence of abnormal blood glucose levels, a condition known as dysglycemia.
Cooked mushrooms are a great source of B vitamins including riboflavin, niacin and B5. The USDA reports that a cup of sliced, grilled Portobello mushrooms contains 23 micrograms of folate, a B vitamin that prevents birth defects and supports enzyme function. Oyster mushrooms contain more than 7 mg of niacin, also known as vitamin B-3, responsible for about 200 enzyme reactions. Cooked oyster mushrooms contain about half of the RDA of niacin.
Science Daily reports that dietary minerals are necessary for every living organism to maintain physical health. One cup of stir-fried shiitake mushrooms contain 290 milligrams of potassium, a mineral that is crucial to heart function, muscle contraction, digestive and muscle function, according to the University of Maryland Medical Center. The RDA for potassium is 4,700 milligrams for adults. A cup of boiled white mushrooms and grilled Portobello mushrooms provide significant amounts of potassium.
A 2007 study published in the “Journal of Agricultural Food Chemistry” by Josefine Enman found that shiitake mushrooms contain the cholesterol-lowering compound eritadenine. A 2005 article published by The Medical News reports that six varieties of mushrooms tested in both raw and cooked forms are rich in dietary fibers that can lower cholesterol and improve heart health. The mushrooms studied include white button, crimini, portabella, maitake, enoki and shiitake.
Cooked mushrooms are low in all forms of unhealthy fats including trans fats and saturated fats, providing, in some cases, less than 1 gram per serving. The American Heart Association reports that trans fats, also known as partially hydrogenated oils, raises bad cholesterol as well as lowers good cholesterol levels. Too much trans fats in your diet could increase your risk of developing heart disease. Saturated fats also raise levels of bad cholesterol.