Molecular hydrogen: a preventive and therapeutic medical gas for various diseases

Since the 2007 discovery that molecular hydrogen (H(2)) has selective antioxidant properties, multiple studies have shown that H(2) has beneficial effects in diverse animal models and human disease. This review discusses H(2) biological effects and potential mechanisms of action in various diseases, including metabolic syndrome, organ injury, and cancer; describes effective H(2) delivery approaches; and summarizes recent progress toward H(2) applications in human medicine. We also discuss remaining questions in H(2) therapy, and conclude with an appeal for a greater role for H(2) in the prevention and treatment of human ailments that are currently major global health burdens. This review makes a case for supporting hydrogen medicine in human disease prevention and therapy.