The Chinese have used the shitake mushroom for medicinal purposes for over 6,000 years; consequently, it has become the Asian symbol for longevity, according to The George Mateljan Foundation’s website The World’s Healthiest Foods. This particular type of edible fungus is the second most commonly cultivated mushroom in the world. With its rich sources of selenium, iron, dietary fiber, protein and vitamin C, research has shown significant benefits in adding shiitake mushrooms to your diet.