Chaga

Description

Chaga (Inonotus obliquus) is a parasitic fungus of the family Hymenochaetaceae with a circumboreal distribution across Russia, Scandinavia, the Baltic region, Asia and North America. Rather than a typical mushroom cap it forms hard, black, cracked sterile masses (sclerotia) up to 40 cm wide on living birch trees (rarely alder, beech or oak); their dark colour comes from a high melanin content, while the interior is cinnamon-brown. These black conks have been used since the 15th–16th century in Russian and Siberian folk medicine, traditionally as a decoction (tea) for gastrointestinal complaints and, in folk tradition, against cancer. The fungus became widely known in the West through Alexander Solzhenitsyn's novel "Cancer Ward". Chaga contains over 200 bioactive substances including polysaccharides (beta-glucans), triterpenes such as betulin and betulinic acid, inotodiol, polyphenols and melanin; robust clinical efficacy in humans has not yet been demonstrated by trials.