Chaga mushroom Inonotus obliquus belonging to the family Hymenochaetaceae of Basidiomycetes. This fungus infects hardwood trees, mostly those from the genus Betula (birches), and to a lesser extent, those from the genera Quercus (oaks), Populus (poplars), Alnus (alders), Fagus (ashes), and Acer (maples). Currently, this fungal species has only been described in the northern hemisphere. Chaga can be found in Canada, in the north of the United States of America, in Kazakhstan, in Siberia, in Ukraine, in Japan, in South Korea, in China, as well as in Europe (mostly in the northern and eastern parts of the continent).
The Chaga mushroom Inonotus obliquus consists of two main parts:
- the fruiting body (brown part), which is found mainly inside
- the sclerotium (black part), which is found mainly outside
The conk (3 – 35 cm) that is used medicinally comprises wood from the birch tree and the mycelium from the invasive fungus. The Chaga mushroom survives seasonal environmental stresses, including freezing temperatures, UV irradiation, and the invasion of pathogens and, as such, has evolved with complex, integrated defences.
2 components derived from birch are frequently described in Chaga: betulin (or betulinol) and betulinic acid. The compounds betulin and betulinic acid were tested in vitro on different models of cancer cells (cutaneous, ovarian, and pulmonary) demonstrating their antiproliferative potential.
The extracts of I. obliquus have been used in China, Korea, Japan, Russia, and the Baltics for their favorable effects on lipid metabolism and cardiac function, as well as for anti-bacterial, anti-inflammatory, anti-oxidant, and anti-tumor activities. I. obliquus extracts were found to inhibit hepatitis C virus and human immunodeficiency virus and demonstrated strong anti-oxidant and immunostimulatory activities in vitro. Several studies investigated the anti-tumor activity of the I. obliquus aqueous extract and found that it suppressed the proliferation and induced apoptosis of various carcinoma cell lines.
However, despite increasing evidence of anticancer activity exhibited by the I. obliquus extract and its individual components, the underlying mechanisms are still unclear and the effects of I. obliquus on cancer prevention are not understood. There is no human clinical proof that Chaga mushrooms can prevent or treat cancer at this time. So far there are pre-clinical but no clinical studies supporting the role of Chaga mushrooms as an anti-inflammatory agent. Chaga mushrooms are the “King” when it comes to antioxidants as compared to other mushrooms, but this is entirely limited to laboratory studies. Therefore, there are needed more researches to prove Chaga mushrooms have health benefits.
Commercially available Chaga mushroom products contain (per 100 g):
- Energy: 167 kcal
- Protein: 0
- Lipid: 0
- Carbohydrate: 33 g
- Vitamin C: 8,333 mg.