The term mushroom describes a variety of fleshy fungi of the class Basidiomycota. The culinary use of edible mushrooms dates back at least to early Roman times, and their healthy use can be traced back for centuries in China.
Though commonly thought to be of little nutritional value because they are mostly made of water, many types of edible mushrooms are now known to be sources of fiber, protein, vitamins and minerals. Perhaps more importantly, many edible mushrooms contain natural compounds with health-promoting properties.
Some mushrooms are used for physiological homeostasis – that means restoring our bodies' balance (for example, the balance of minerals, enzymes, hormones, water, electrolytes or immune cells) and natural resistance to disease: Shiitake (Lentinula edodes) and maitake (Grifola frondosa) are two popular mushrooms that contain beta-glucan (a type of polysaccharide). Both have been used in traditional Chinese and Japanese herbology for immune support. Reishi (Ganoderma lucidum) is known as the “elixir of life” in China. It contains polysaccharides, alkaloids and triterpene acids, which are thought to be responsible for its invigorating effects.