Harmful Effects of Antioxidant Therapy

Abstract

Oxidative stress has an integral role in the pathophysiology of most human diseases. With a rapidly aging population, increased attention and study have been directed toward the use of antioxidant therapy. The appeal is that these agents are considered “natural” substances and are associated with a healthy diet. The hypothesis has been that decreasing oxidative stress may prevent disease processes such as cancer or coronary heart disease. Since much of the general population are relatively healthy patients, it is critically important that these supplements are free of toxicity and side effects. While initial studies of antioxidant supplementation suggested a beneficial role in disease prevention, more recent clinical trials and a meta-analysis have questioned the benefit of these therapies. Several studies have suggested that excess supplementation may in fact be harmful. Recent attention has also focused on the use of antioxidants for the treatment of male infertility. The focus of this chapter is the potentially harmful effects of antioxidant therapy.