Relationship between Nutrition and Aging

One of the most critical needs in nutritional research at the present time is a knowledge of the levels of intake of various nutrients at specific intervals in the life cycle which will optimize physical and mental development, physiological performance during adulthood, and the retention of health and vigor in senescence. In the past, emphasis had been placed primarily on the establishment of the nutritional requirements of young growing animals. Few efforts have been made to determine whether changes occur in nutritional requirements following growth cessation. This is unfortunate because many age changes in physiological functions may result in increased nutritional needs in later life. In addition, it is generally accepted that intakes moderately above the recommended allowances are optimal for the well-being of an organism. However, a number of studies carried out on animals have demonstrated that longevity was increased when intakes of certain nutrients were lower than the recommended allowances. Therefore, an attempt is made here to review the pertinent literature on (1) the effect of age on nutritional requirements following the cessation of growth and (2) the effect of nutrition on lifespan. This information may provide useful knowledge for the optimal nutrition of the aged and for an understanding of the basic mechanisms of biological aging. Studies concerned with the first problem area heve been carried out principally in human subjects, whereas those with the second area, in animals.