Abstract and Introduction
Objective: To review the importance of antioxidant nutrients in the maintenance of health and the prevention and treatment of disease, with a focus on data pertaining to vitamin C, vitamin E, selenium, and carotenoids. A secondary objective was to discuss the new Dietary Reference Intakes released by the Institute of Medicine (IOM) for these nutrients.
Data Sources: IOM reports on the use of antioxidant vitamins were reviewed for nutrient recommendations. In addition, a MEDLINE search was performed to identify recent research and review articles on the topic, which were analyzed to identify key research findings in the area.
Data Synthesis: The review discusses the biologic processes of oxidation reactions and antioxidants in biologic systems, provides an overview of information on selected antioxidant nutrients, and explores their role in the prevention and treatment of cancer, cardiovascular disease, ocular disorders, and respiratory disorders.
Conclusion: There appear to be significant health benefits from dietary antioxidants, as can be found in fruits and vegetables. Some prospective assessment of the effect of supplemental antioxidants also suggests benefit, especially for vitamin E; however, there are conflicting results in this area. Overall, it appears that antioxidant nutrients, especially those from food sources, have important roles in preventing pathogenic processes related to cancer, cardiovascular disease, macular degeneration, cataracts, and asthma, and may enhance immune function.
It is estimated that 40% of the U.S. population takes vitamin supplements, and recently much public and scientific interest has been directed toward antioxidants in particular.
Antioxidant nutrients are believed to play a role in the prevention and treatment of a variety of chronic diseases, ranging from asthma to cardiovascular disease (CVD) and cancer. The proposed mechanism by which antioxidants protect cells from oxidative stress is by scavenging free radicals and halting lipid peroxidation chain reactions, which can cause DNA damage.
In light of new research on the importance of these vitamins to overall heath, the Institute of Medicine (IOM) recently released new dietary guidelines for intake of the antioxidant nutrients vitamin C, vitamin E, carotenoids, and selenium. In addition, a variety of other nutrients are believed to be involved in antioxidant processes.
This article reviews antioxidant processes in biologic systems and properties of selected antioxidant nutrients. In addition, a summary of the benefits of antioxidant nutrients in enhancing immune function and in the prevention and treatment of cancer, CVD, and certain ocular and respiratory disorders is provided. Finally, counseling tips are provided for pharmacists who may be questioned about the health benefits of antioxidant supplements.