In this new series of books, the importance of oxidative stress in diseases associated with organ systems of the body will be highlighted by exploring the scientific evidence and the medical applications of this knowledge. The series will also highlight the major natural antioxidant enzymes and antioxidant substances such as vitamins E, A, and C, flavonoids, polyphenols, carotenoids, lipoic acid, and other nutrients present in food and beverages. Oxidative stress is an underlying factor in health and disease. More and more evidence indicates that a proper balance between oxidants and antioxidants is involved in maintaining health and longevity and that altering this balance in favor of oxidants may result in pathological responses causing functional disorders and disease. This series is intended for researchers in the basic biomedical sciences and clinicians. The potential for healthy aging and disease prevention necessitates gaining further knowledge about how oxidants and antioxidants affect biological systems. Rapid progress in the application of antioxidant substances and other micronutrients warranted a revision and update of Handbook of Antioxidants, highlighting new fundamental studies on food-derived antioxidants and biomarkers, vitamins E and C, coenzyme Q, carotenoids, flavonoids and other polyphenols, antioxidants in beverages and herbal products, the thiol antioxidants glutathione and lipoic acid, melatonin, selenium, and nitric oxide. Handbook of Antioxidants: Second Edition, Revised and Expanded, is an authoritative volume regarding the chemical, biological, and clinical aspects of antioxidant molecules. The individual chapters provide an in-depth account of the current knowledge of vitamins or other naturally occurring antioxidant compounds and discuss critically the new aspects of antioxidant therapy. We are delighted to have been involved with this project and are grateful to the authors in this volume for their outstanding contributions.