Nutritional Value of Mushrooms: What Makes Fungi a Nutritional Powerhouse HealthcareOnTime In a study, researchers found that mushrooms have high amounts of the ergothioneine and glutathione, both important antioxidants, said the senior author. The researchers also found that the amounts the two compounds Mushrooms: A rich source of the antioxidants ergothioneine and glutathione ScienceDirect Mushrooms contain high amounts of antioxidants that combat aging and promote health