"Laboratory and animal studies show that compounds in chaga can kill cancer cells selectively and stimulate the immune system."(2) A petri dish study in 2010 showed that it specifically slowed down growth of "lung, breast, and cervical cancer cells". Chaga and some other mushrooms contain triterpenes, compounds that cause cancer cells to self-destruct without harming healthy cells like more standard cancer treatments(1). "Chaga may also reduce fatigue and inflammation, and increase mental sharpness."(2) Its antioxidants abound enough to where it may lower blood pressure and LDL cholesterol. A 2006 study in rats showed the ability to lower blood sugar(1).
Note: Chaga does have quite a bit of oxalates and so tons shouldn't be consumed. Diabetics and those on blood thinners or with kidney issues may need to watch or forgo consumption of chaga.(2)
References:
1. Villines, Zawn. "Nine potential health benefits of chaga mushrooms." Medical News Today. Healthline Media UK Ltd, a Red Ventures Company. 22 Jul. 2017. Web. 16 Apr. 2021. https://www.medicalnewstoday.com/articles/318527.
2. "Chaga Mushroom." Memorial Sloan Kettering Cancer Center. Memorial Sloan Kettering Cancer Center. 3 Feb. 2021. Web. 16 Apr. 2021. https://www.mskcc.org/cancer-care/integrative-medicine/herbs/chaga-mushroom.