“He could not imagine any greater joy than to go away into the woods for months on end, to break off this chaga, crumble it, boil it up on a campfire, drink it and get well like an animal. To walk through the forest for months, to know no other care than to get better! Just as a dog goes to search for some mysterious grass that will save him…”
—Nobel laureate Alexander Solzhenitsyn, Cancer Ward (1968)
The chaga mushroom (Inonotus obliquus) has a long tradition in folk medicine. Legends of chaga use go back thousands of years, and some people claim that 5300-year-old Ötzi the Iceman may have carried chaga in his pouch . In the 12th century, the Grand Prince of Kievan Rus, Tsar Vladimir Monomakh, is said to have used chaga to cure lip cancer [2, 3].
The first verifiable mention of chaga appeared during the 16th century, when Russian and northern European medical texts described chaga as a treatment for ailments including cancer, tuberculosis, gastritis, and ulcers . Since then, chaga has been consistently documented as a powerful and effective treatment for everything from fatigue to cancer.
What does the research say?
Although there was some interest in researching chaga in Russia in the mid-20th century, most of the research we have is preclinical, meaning that it wasn’t done in humans.
There are a few human studies we can look at to determine whether chaga is actually beneficial, but most of the empirical data on chaga is preclinical (i.e. not in humans) at this point. The reason for this is because scientists first need to prove that it’s safe and effective in animals and in in vitro human cell cultures before testing it on volunteers. Notably, nearly all currently available data strongly support centuries-old claims that chaga offers substantial health benefits.
The little research we have on the clinical utility of chaga in humans comes from Russia. Studies done in 1959 and 1961 showed that 3-4 weeks of chaga administration to stage III-IV cancer patients reduced cancer pain so much that patients were able to stop taking narcotic pain medications .
In 1973, a study was done to test the effects of orally administered chaga on psoriasis that co-occurred with gastrointestinal issues (ulcers, colitis, frequently upset stomach). It took 8-12 weeks before people started noticing changes, but by 6 months of use, even extensive psoriasis with massive plaques were mostly or completely cured. People with chronic GI troubles reported the most benefit, and everyone who participated in the study reported increased vitality .
Lots of research on the mechanisms and effects of chaga are currently underway. Some recent studies have demonstrated that chaga has powerful therapeutic effects:
- Cancer: Lots of research is being done to learn how chaga slows cancer progression . In animal models, chaga has been shown to suppress several types of cancer, including lung [5, 6], breast , colorectal , and melanoma .
- Kidney disease: A study in mice with kidney disease found that chaga reduced fibrosis and inflammation while increasing overall kidney health .
- Liver injury/disease: Animal studies have shown that chaga reduces inflammation and oxidative damage in liver cells [11, 12].
- Cardiovascular complications: Age-related degeneration of heart tissue increases risk for heart failure. When chaga is given to old mice, heart cells became healthier and overall cardiovascular function improved .
- Allergies: Histamine is a potent allergen that causes inflammation and allergic responses. Mice who were given chaga had fewer allergy symptoms after histamine exposure .
- Inflammatory bowel disease (IBD): Chaga improved IBD symptoms in mice .
- Inflammation/free radicals: Human cells that were treated with a chaga extract had reduced damage from dangerous free radicals (oxidants), supporting the use of chaga as an antioxidant .
- Diabetes: Diabetic mice that were treated with chaga had significant metabolic improvements and healthier blood sugar levels .
- Fatigue: One study showed that chaga administration reduced fatigue in swimming mice .
- Anti-viral: Studies in human and animal cells have shown that chaga can suppress infections caused by hepatitis C  and herpes .
How does chaga work?
Scientists have isolated several “bioactive” compounds from chaga mushrooms. Bioactive compounds are obtained from your diet, and they have positive effects on health and wellbeing.
Some of the bioactive compounds that have been identified in chaga are:
- Polyphenols: Polyphenols are potent antioxidants that protect cells our brains and bodies from damage caused by unstable molecules . Chaga mushrooms produce at least six different types of polyphenol .
- Inotodiol: This beneficial steroid reduces inflammation and suppresses cancer progression .
- 3,4-dihydroxybenzalacetone (DBL): DBL reduces DNA damage caused by normal aging and improves cardiovascular health .
- Betulin and betulinic acid: These compounds have several therapeutic benefits, including anti-inflammation, anti-cancer, improved arthritis, and liver protection, among others .
- Ergosterol: Ergosterol is steroid that’s unique to fungi. It’s an important precursor of vitamin D2 and inhibits some types of cancer .
- Polysaccharides: Several polysaccharides that improve immunity and limit the spread of cancer have been found in chaga mushrooms [9, 23].
Is chaga safe?
Studies on chaga have demonstrated that it is safe and generally well tolerated. However, as with any drug or supplement, it is important to take chaga as directed. It’s also important to get chaga from a reputable source to ensure that it’s high quality and free from environmental pollutants that growing mushrooms might be exposed to .
There are two types of medication that shouldn’t be combined with chaga: blood-thinning medications and diabetes medications . Chaga enhances the effects of these drugs, leading to overly “thin” blood that doesn’t clot, and dangerously low blood pressure, respectively.
Chaga mushrooms have been safely used to improve health and treat disease for centuries, and scientists are starting to understand exactly how they work. Plenty of data shows that chaga has powerful anti-inflammatory and antioxidant properties, slows cancer progression, improves liver and kidney function, and may even prevent some viral infections.
Even though chaga has a long history of improving health and wellbeing, scientific investigation on the effects of chaga is in its early stages. It’s important to note that most of the empirical data we have so far comes from in vitro (e.g. human cells in a petri dish) and animal studies, so there is a lot of work yet to be done. However, animals have similar cellular and molecular pathways to ours, and data from animal studies are consistent with anecdotal reports from people who have used chaga.
- Kopp, J. Chaga's Mysterious History. 2018 [cited 2020 March 20]; Available from: https://birchboys.com/blogs/about-our-chaga/a-short-history-of-chaga.
- Shikov, A.N., et al., Medicinal plants of the Russian Pharmacopoeia; their history and applications. J Ethnopharmacol, 2014. 154(3): p. 481-536.
- Curran, K. What are Chaga mushrooms? 2020 [cited 2020 March 21]; Available from: http://www.ethnoherbalist.com/chaga-extract-mushroom-tea-benefits/.
- Arata, S., et al., Continuous intake of the Chaga mushroom (Inonotus obliquus) aqueous extract suppresses cancer progression and maintains body temperature in mice. Heliyon, 2016. 2(5): p. e00111.
- Géry, A., et al., Chaga (Inonotus obliquus), a Future Potential Medicinal Fungus in Oncology? A Chemical Study and a Comparison of the Cytotoxicity Against Human Lung Adenocarcinoma Cells (A549) and Human Bronchial Epithelial Cells (BEAS-2B). Integr Cancer Ther, 2018. 17(3): p. 832-843.
- Jiang, S., et al., Inonotus obliquus polysaccharides induces apoptosis of lung cancer cells and alters energy metabolism via the LKB1/AMPK axis. Int J Biol Macromol, 2019.
- Zhang, X., C. Bao, and J. Zhang, Inotodiol suppresses proliferation of breast cancer in rat model of type 2 diabetes mellitus via downregulation of β-catenin signaling. Biomed Pharmacother, 2018. 99: p. 142-150.
- Kang, J.H., et al., Ergosterol peroxide from Chaga mushroom (Inonotus obliquus) exhibits anti-cancer activity by down-regulation of the β-catenin pathway in colorectal cancer. J Ethnopharmacol, 2015. 173: p. 303-12.
- Lee, K.R., et al., Polysaccharide isolated from the liquid culture broth of Inonotus obliquus suppresses invasion of B16-F10 melanoma cells via AKT/NF-κB signaling pathway. Mol Med Rep, 2016. 14(5): p. 4429-4435.
- Chou, Y.J., et al., Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP) on HFD/STZ-Induced Nephropathy in Mice. Int J Mol Sci, 2016. 17(9).
- Hong, K.B., et al., Hepatoprotective Activity of Water Extracts from Chaga Medicinal Mushroom, Inonotus obliquus (Higher Basidiomycetes) Against Tert-Butyl Hydroperoxide-Induced Oxidative Liver Injury in Primary Cultured Rat Hepatocytes. Int J Med Mushrooms, 2015. 17(11): p. 1069-76.
- Xu, L., et al., The polysaccharide from Inonotus obliquus protects mice from Toxoplasma gondii-induced liver injury. Int J Biol Macromol, 2019. 125: p. 1-8.
- Giridharan, V.V., et al., 3,4-Dihydroxybenzalacetone (DBL) Prevents Aging-Induced Myocardial Changes in Senescence-Accelerated Mouse-Prone 8 (SAMP8) Mice. Cells, 2020. 9(3).
- Javed, S., et al., Inonotus obliquus attenuates histamine-induced microvascular inflammation. PLoS One, 2019. 14(8): p. e0220776.
- Mishra, S.K., et al., Orally administered aqueous extract of Inonotus obliquus ameliorates acute inflammation in dextran sulfate sodium (DSS)-induced colitis in mice. J Ethnopharmacol, 2012. 143(2): p. 524-32.
- Gao, X., et al., Antioxidant, α-amylase and α-glucosidase activity of various solvent fractions of I. obliquus and the preventive role of active fraction against H2 O2 induced damage in hepatic L02 cells as fungisome. J Food Sci, 2020.
- Wang, J., et al., Antidiabetic activities of polysaccharides separated from Inonotus obliquus via the modulation of oxidative stress in mice with streptozotocin-induced diabetes. PLoS One, 2017. 12(6): p. e0180476.
- Yue, Z., et al., Effect of Inonotus Obliquus Polysaccharides on physical fatigue in mice. J Tradit Chin Med, 2015. 35(4): p. 468-72.
- Shibnev, V.A., et al., Antiviral activity of Inonotus obliquus fungus extract towards infection caused by hepatitis C virus in cell cultures. Bull Exp Biol Med, 2011. 151(5): p. 612-4.
- Pan, H.H., et al., Aqueous extract from a Chaga medicinal mushroom, Inonotus obliquus (higher Basidiomycetes), prevents herpes simplex virus entry through inhibition of viral-induced membrane fusion. Int J Med Mushrooms, 2013. 15(1): p. 29-38.
- Grosso, G., Effects of Polyphenol-Rich Foods on Human Health. Nutrients, 2018. 10(8): p. 1089.
- Lee, I.K., et al., New antioxidant polyphenols from the medicinal mushroom Inonotus obliquus. Bioorg Med Chem Lett, 2007. 17(24): p. 6678-81.
- Chen, Y., et al., Purification, characterization and biological activity of a novel polysaccharide from Inonotus obliquus. Int J Biol Macromol, 2015. 79: p. 587-94.
- NeurogalMD. Chaga Mushroom Evidence Review: Are the Benefits of Chaga Real? 2019 [cited 2020 March 21]; Available from: https://neurogal.com/neuro-blog/2019/2/11/chaga-mushroom-evidence-review-are-the-benefits-of-chaga-real.