Causes of reductive stress in male reproduction

As there is concern for oxidative stress and its effects on male fertility, antioxidant supplementation has been used as a means of combating oxidative stress in the modern-day lifestyle. Antioxidant supplementation, however, is currently unregulated and has the potential to cause or perpetuate tissue injury. Shifting the equilibrium of chemical reactions within the human body away from oxidation and toward the other extreme is also not without its risks. While additional studies are needed, there is an emerging understanding of the clinical manifestations of reductive stress. An abundance of reducing agents can result in loss of necessary oxidation mechanisms, promotion of additional tissue injury, and a paradoxical increase in reactive oxygen species. This chapter discusses the antioxidant paradox, identifies enzymatic and nonenzymatic reducing agents within the male reproductive system, and reviews the clinical implications of reductive stress.