Chaga is a natural medicine that is unlike other medicinal mushrooms. That’s because Chaga isn’t actually a mushroom at all. Chaga is a “sterile conk” or canker. It grows on the side of trees, primarily Birch, and is induced by a fungus called Inonotus obliquus. This makes it unique in comparison to other medicinal fungi as it contains bioactive compounds from both the fungus and its tree host.
Chaga has been used traditionally in Russia, Siberia, Canada, Alaska, and many Circumboreal cultures. It is traditionally used for many different purposes, including digestive issues, cancer, viral infections, and skin problems. Today it has become popularized for its high antioxidant content, immuno-modulatory effects, and the treatment/prevention of cancer. Studies also suggest it could help with diabetes and other chronic health conditions. While there are some very promising effects attributed to Chaga, a lack of human clinical trials still places uncertainty on the efficacy and proper usage of Chaga.
Natural History Of Chaga
The ecology of Chaga is a tale of two antagonists, a tree host and a parasitic fungus. Together they form a “phyto fungal” canker composed of both plant and fungal tissues. Cankers, just for reference, are tumor-like growths that you can see on the sides of many trees. They are most often induced by bacterial or fungal pathogens and are diverse.
Chaga is produced by a fungus called Inonotus obliquus which an overwhelming majority of the time parasitizes Birch. Although rare, Chaga has been reported from Alder, Beech, and Maple amongst others. It is estimated that Chaga only grows on less than 0.1% of Birch trees.
Chaga is pretty easy to identify, especially when growing on Birch. Identifications can get tricky when we add other tree species into the equation, which can be quite challenging for amateurs to identify. They are spherical and have an outside that is black charcoal and crusted texture. They can grow from the size of a fist to the size of your head, and even bigger. The inside of the canker is fibrous, woody, and with a distinct yellow coloring. They may occur high up in the canopy.
It’s interesting to note that there are approximately 100 species in the genus Inonotus. Some of these form “sterile conks” or cankers, but the majority form a-typical polypore fruiting bodies.
Inonotus obliquus is considered a parasite and causes white rot on the heartwood of the trees. It infects its host via spores that enter wounds on the bark. Evidence suggests spores are likely dispersed by insects. The most common hosts are birch trees between 30 and 50 years of age.
Once infected, the tree and the fungus produce an intertwined plant/fungal biomass that slowly grows on the tree. These cankers can grow for more than 30 years and the fungus can eventually result in the death of the host. It is assumed there must be intricate phytochemical “warfare” occurring within these cankers, with trees producing defense compounds and Inonotus defending itself from them.
The “sterile conk” that we know as Chaga is often wrongly regarded as being a solid mass of mycelium termed sclerotium. While there is still a lot of research needed to properly identify the characteristics of these growths, research shows these cankers are a composite of sclerotial mycellium and plant tissues. Emerging research suggests that the mycelial biomass within the cankers could be as low as 10% or lower.
While the Chaga canker is not a mushroom, it doesn’t mean the Inonotus obliquus doesn’t produce mushrooms. They produce mushrooms once in their life cycle at the end of their host’s life.
These begin growing beneath the bark, forming a crust-like pored structure that can be up to 4 meters in length along the trunk. Once mature the bark often withers away exposing the inconspicuous fruiting bodies. These are also relatively short-lived as they are devoured by insects, who are assumed to be responsible for the dispersal of the spores. Seeing the actual fruiting bodies is rare and infrequently documented.
The distribution of Chaga is largely limited to northern latitudes. In North America, Chaga reaches its southern distribution in the southern Appalachian mountains. Its range extends north following the mountain range and then becomes widespread in the Northeast USA and Canada. It is also found in the Canadian Rockies, British Columbia, and Alaska. Other than in Alaska, Chaga is not found in the western United States.
Chaga is widespread in central and northern Europe. Its distribution is largely concentrated around the Baltic countries and Russia. Chaga has been reported from the UK, Netherlands, Germany, Denmark, Poland, Finland, Sweden, Estonia, Russia, Austria, and neighboring countries. Chaga is considered rare in western and southern Europe.
Chaga has been reported in China, Korea, Japan, and even Thailand. Analysis of the Thai Chaga has shown it contains a distinct chemical profile.
Sustainability of Chaga
Chaga is relatively scarce in nature and there are pertinent issues with its overharvesting. This is because when Chaga is harvested, foragers remove a vegetative structure that could take well over 5-10 years to grow. They are not like mushrooms which form ephemeral reproductive structures that are harvested.
This can not only greatly diminish the resource in heavily exploited areas, but it could negatively affect the lifecycle and future abundance. While Birch forests may seem abundant in some parts of the world, there is a growing demand for Chaga. The fact that thousands of Chaga products are listed on Amazon alone gives a legitimate reason for concern.
For this reason, it is best to find a provider of Chaga who knows the origins of their product and can ensure a sustainable harvest. We should also keep in mind that overexploitation of this resource could reduce its accessibility to those with medical conditions who want to incorporate it into their treatments. Many experts discourage and frown upon the use of Chaga if not used as part of a conscious holistic treatment for a medical condition.
Cultivation Of Chaga
True Chaga has not yet been cultivated on a commercial scale. Chaga products claiming to be cultivated are typically Inonotus obliquus mycelium grown on grain which does not have the same bioactivity as the wild canker. Experts generally agree that these myceliated products are not as effective.
The inoculation of host trees has been shown to be possible and successful. Since Chaga only occurs on less than 0.1% of Birch trees this technique has great potential and could be incorporated into sustainable forest management plans. This is an emerging practice that will still require time and research before it becomes commercially available.
Traditional Uses Of Chaga
It’s believed that Chaga has been used for well over 1000 years by traditional cultures in Europe and North America. The first account of Chaga being used in medicine dates back to the Persian physician and scientist Avicenna from the 11th century. While this record is repeatedly cited, it lacks verification. In the 12th century, there is a historical tale claiming that Duke Vladimir Monomakh of Russia cured a cancerous lip tumor using Chaga.
Indeed Chaga has been used in Russia since the 16th century for the treatment of various types of cancer. In Siberia, it’s also been used historically to treat tuberculosis, gastritis, stomach ulcers, and liver problems. The Khanty peoples of Siberia would ignite Chaga and once it was a fiery ember, they’d extinguish it in hot water. This water was then used for feminine hygiene post-birth.
Since the 20th century Chaga has been consumed as a cheaper alternative to tea for economically disadvantaged rural communities in eastern Europe. By 1955 the USSR Ministry of Health recognized the therapeutic properties of Chaga and it was included in the Soviet Pharmacopeia. Chaga also has a history of consumption in China, Korea, and Japan, although it’s not as prevalent as other medicinal fungi.
In North America, it is known that Chaga was traditionally used by the First Nations of Canada and the United States. Here it was used by the Cree people of Alberta, the Wet’suwet’en of British Columbia, the Tenaina of Alaska, and many other native communities. Its uses greatly varied, from the treatment of viral infections and pains to the use as incense, tinder, and even for ceremonial purposes.
Medicinal Uses Of Chaga
Modern chemical analysis shows Chaga contains many different constituents known to have health benefits. These compounds include beta-glucans, polyphenols, and triterpenoids just to name a few. The main mechanisms of action in Chaga are presumed to be due to its high antioxidant content, immunomodulating properties, and it’s anti-inflammatory effects. Chaga is shown to have the potential for improving cancer treatments, regulating blood sugar levels, improving gut health, improving heart health, protecting the brain, and more.
It is also important to emphasize the use of Chaga as part of a conscious health routine that incorporates diet, exercise, and other lifestyle choices. Using Chaga in addition to these good habits will be most effective for the treatment or prevention of disease.
Clinical Trials For Chaga Are Needed
While there has been a good amount of research conducted on Chaga, there is a need for human clinical trials to fully understand its health effects. Most scientific studies have been conducted “in vitro” on cultured cell models or in animals like mice. Other medicinal properties are inference based on the chemical analysis and composition of Chaga.
While these tests give us a really good baseline, their results do not always accurately represent the medicinal effects on the human body. And yes, traditional uses are also very good evidence for its effectiveness but clinical trials would allow us to know for what conditions Chaga is most effective and how it should be properly administered (dose, frequency, timespan, etc.).
Safety Of Chaga
While Chaga is considered safe there are some health concerns related to the daily consumption of Chaga. First of all, Chaga is known to be a blood thinner. This could cause complications with medications, particularly for individuals already taking blood thinners. This could also be an issue for individuals undergoing surgery.
Another health concern is the high levels of oxalates in Chaga. These compounds are found in many foods like chocolate, almonds, and spinach, and have been shown to cause or aggravate the disease. Before you worry, evidence suggests that Oxalate related illnesses often occur in individuals with preexisting health conditions. In particular, gastrointestinal diseases and microbial imbalances may be related to oxalate-induced illness. For healthy individuals, many oxalate-rich foods are a nutritional addition to your diet.
This being said, Chaga should be used with caution. Particularly for individuals with osteoporosis, malnutrition, chronic digestive issues, and an existing history of liver/kidney problems. Some experts also caution against the use of Chaga for patients with diabetes, autoimmune diseases, or those who have recently taken antibiotics. It is best to talk to your doctor before using Chaga regularly, especially if you have preexisting health conditions.
Chaga contains a high quantity of triterpenoids similar to other polypores such as Reishi. These compounds have been shown to have many health benefits, particularly for immune function. In Chaga, these are primarily inotodiol, trametolenic acid, and betulinic acid. Inotodiol is the most important and has been shown to improve immune function and be an antioxidant.
Betulinic acid and its precursor betulin are present in Chaga but actually produced by the Birch tree. These compounds are potent antioxidants that help with gastrointestinal issues, and benefit the immune system.
These are another class of Triterpenoids commonly found in fungi that exhibit interesting bioactivity. Ergosterol is a sterol found of particular significance as it has been found to support immune health and have antitumor properties. It is also a precursor to Vitamin D. Lanosterol is also found in Chaga and is a precursor molecule from which many steroids are derived.
- Phenols and Antioxidant Properties Of Chaga
Chaga is highly acclaimed for its antioxidant properties and is often cited as having more than 1000x the antioxidants of blueberries. While various studies show that Chaga is indeed high in antioxidants, recent advancements suggest these numbers do not reflect the true antioxidative potential of these fungi. This high antioxidant count is largely due to phenols present within the fungi.
Melanin, a polyphenol-rich compound, is found in significant quantities in Chaga. It forms this pigment on the exterior of the canker, likely to protect it in the long summer days of northern latitudes. Melanin has been shown to have high antioxidant properties and be generally beneficial for your health.
Chaga also contains beta-glucans like many of the other popular medicinal mushrooms. These are known to have antitumor properties and help improve immune function. As you might expect, Chaga contains significantly fewer beta-glucans compared to other “mushrooms” as it’s largely made of woody plant materials.
Chaga May Improve Immune Function
- Chaga extracts were shown to have immunomodulatory effects on bone marrow cells that were chemically immunosuppressed in mice. As early as 8 days after treatment, various immune cells returned to levels of non-immunosuppressed mice. (Kim, 2005)
- Chaga was shown to help improve liver lymphocyte immune function in male rats with liver damage. (Chi-Sun, 2010)
- Water-soluble polysaccharides from Chaga were shown to significantly enhance the immune response of tumor-bearing mice. (Fan, 2012)
- Chaga extracts were shown to have strong antiviral effects on herpes simplex virus infection. (Pan, 2013)
- Terpenoids from Chaga may interfere with SARS-CoV-2 Spike Protein recognition of host cells. (Basai, 2021)
- Aqueous extracts of Chaga were shown to have antiviral effects against HIV. (Virusologii, 2015)
- Aqueous extracts of Chaga were shown to have preventative and therapeutic effects against hepatitis C. (Shubnev, 2011)
Chaga has Anti-Cancer Potential
- In-vitro studies on various cancer cell lines show Chaga extract has an anticancer effect resulting in a decrease in tumor cell proliferation and mobility. It was shown to have no toxic effects on normal cells. (Marta, 2011)
- Ergosterol peroxide from Chaga had anti-cancer activities on colon cancer cells. This was shown to be by the downregulation of the β-catenin pathway. (Kang, 2015)
- Chaga extracts were shown to suppress the growth of tumors in mice models. In a tumor-bearing mice model, 60% tumor reduction was observed. (Arata, 2016)
- Water extracts from Chaga plus green tea were shown to inhibit human cancer cells in-vitro. (Cha, 2006)
Chaga May Help With Diabetes
- Chaga extracts in alloxan-induced diabetic mice showed a significant decrease in blood glucose levels. These levels decreased up to 20% after 7 days and up to 36% after 21t days of consuming Chaga extracts. (Xu, 2010)
- Studies on genetically diabetic mice showed that Chaga extracts helped with many health symptoms associated with diabetes. (Hee-ok, 2007)
- Fermented Chaga exhibited a hypoglycemic and antioxidative effect in mice with type 1 diabetes. (Young, 2005)
- Fermented Chaga mushrooms may exert hypoglycemic effects on genetically manipulated diabetic rats. After 8 weeks of treatment, there was an increased blood insulin concentration. (Young, 2006)
Chaga May Improve Brain Health
- Significant cognitive enhancement was observed in mice with scopolamine-induced cognitive dysfunction. This is likely related to high antioxidant properties and inhibition of an anti-oxidant enzyme. (Giridharan, 2011)
- Chaga was shown to have neuroprotective effects from beta-amyloid-induced neurotoxicity in brain cells and aging rats. (Xin, 2021)
- Polysaccharides from Chaga may protect against Alzheimer’s disease by regulating Nrf2 signaling, exerting antioxidative effects, and antiapoptotic effects. (Han, 2019)
Chaga May Improve Gut Health
- Chaga mycelium cultivated on brown rice was shown to reduce inflammation due to colitis in mice. (Debnath, 2012)
- Aqueous extracts of Chaga showed anti-inflammatory effects in dextran sulfate sodium indeed colitis in mice. (Mishra, 2012)
- Chaga extracts were shown to have antiulcer effects in rats with ethanol-induced gastric mucosal ulceration. (Xin, 2019)
- Polysaccharide from Chaga was shown to help regulate gut microbiota of chronic pancreatitis in mice. (Hu, 2017)
How To Consume Chaga
There are many ways to consume Chaga, some of which may be more conducive to your lifestyle and health. It is important to consider that clinical trials are still needed to effectively understand the extraction processes, their effectiveness, and proper dosages. Recommended dosages are largely inferences from traditional usage and the intuition/clinical experience of experts.
Fresh or Dry Chaga Decoction
The most traditional way to consume Chaga is to extract it in hot water for at least 3 to 4 hours. This should be done in a pot on low heat with temperatures just below boiling. Some choose to do this process for longer. Pulverizing Chaga will greatly reduce the required cooking time by at least half. After a preliminary decoction, many use the filtered remains to conduct a second extraction and continue doing so until there is an insignificant color change in the liquid.
Dose: About 2-3 grams
Dried powders are typically made by pulverizing pure Chaga, although some may be from myceliated grain. As previously mentioned, myceliated grain may not be as effective as the canker itself.
- Activated powders have been processed in a way that all make the medicinal compounds bioavailable. This means it can be placed directly into a smoothie, coffee, or other foods/beverages.
- If your powder does not state that it was activated then you must decoct it in hot water or you could incorporate it while cooking into a brothy food item.
Dose: About 2-3 grams.
Extracts are concentrated forms of the medicinal constituents that have been separated from the raw biomass. These are much more potent and completely bioavailable. Full-spectrum extractions remove all water-soluble and non-water soluble components.
- Tinctures are liquid extracts that most often contain a water extraction and alcohol extraction mixed into one. Dose: About 1-2 dropper fulls but consult with the product packaging or producer directly.
- Powdered Extracts are the medicinal constituents in their most potent form. This is often the most effective way to consume Chaga. They are also convenient when added to other supplement blends or food items. Dose: Around 500-1000mg but you should consult the packaging or producer directly.
- For the most potent Chaga extracts, check out 2 of our articles on the best Chaga supplements in the US and Canada, and the best Chaga mushrooms in Australia
Capsules typically contain powdered extracts. They are convenient as the doses are premeasured so there’s no guesswork involved. Also, they can be easily incorporated into existing routines. Dose: 1 to 2 pills a day or as indicated by the producer.
Incorporating Chaga Into A Health Routine
While Chaga has many promising health benefits, it is most beneficial when incorporated into a conscious health routine. This means a proper diet, exercise, and healthy lifestyle choices. It’s also important to consider that the beneficial health effects of Chaga may only occur after consuming it for several weeks.
Its questionable sustainability, potential health risks, and lack of clinical trials may also make you reconsider taking Chaga regularly. While there is room for Chaga in certain medical contexts, other herbs or medications may also be more effective.
Even still, many people choose to consume Chaga and report many health benefits from it. Thus if this is a medication you believe in or find potential in, you may want to consider consciously incorporating it into your routine. Careful monitoring and observation of your health will be the best way to tell if Chaga is right for you.
- Environmental Science and Mycology Researcher, Author, Contributor
- Humboldt State University Bachelor of Science (B.S.), Environmental Science with focus on Ecological Restoration.
- Former President of the Mycology Club at Humboldt State University
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