Much literature has been published showing the causal relationship of reactive oxygen/nitrogen species in human disease conditions, and there has been an explosion in the understanding of oxidative stress, the protective role of antioxidants and molecular events involved in the regulation of transcription, editing, and translation of key events leading to disease processes. Strategies need to be developed for prevention of diseases by allowing scientists and clinicians to obtain information on emerging advances. The molecular mechanisms involved in several diseases including Alzheimer's disease, atherosclerosis, diabetes, arthritis, and Parkinson's disease, as well as disorders of the eye, skin, cardiac, and pulmonary systems are discussed in this volume, along with scientific evidence supporting the value of dietary supplementation with antioxidants in the prevention of cellular damage leading to chronic disease. Special in vivo techniques are also discussed at length, along with the role of molecular studies in human risk assessment.