Diabetes is an oxidative stress disorder as a result of both hyperglycemia and increased levels of free fatty acids. Oxidative stress has been implicated in the pathogenesis of diabetes-related complications, and treatment with antioxidants seemed to be a promising therapeutic option. Although animal studies and preliminary human studies were initially encouraging, subsequent human studies have failed to show a clear benefit of antioxidants, whereas some studies have even suggested that they can be potentially harmful. Therefore, treatment with antioxidants cannot be currently recommended as a therapeutic option.