The role of nutrition in aging

Nutritional requirements do not change appreciably with age among adults. However, with increasing age total caloric intake is gradually reduced, but among normal people living in the community dietary deficiencies are seldom found. Deficiencies in specific nutritional elements are found among poor and disadvantaged elderly people. The use of special diets or the ingestion of megadoses of vitamins do not improve health or prolong life. The reduction in food intake and the tendency of old people to eat the same diet day after day makes them potentially vulnerable to possible deficiencies in specific vitamins, minerals, and protein. In most animal species (rats, mice, fruit flies, rotifers), a reduction in the daily food intake over the entire life-span increases it. The mechanisms of this increase are not known. Although there are rational reasons to believe that nutrition must play an important role in aging, experimental data to prove relationships are most scanty. The field of nutrition and gerontology share many difficulties, viz the lack of a biological index of aging and an index of optimal nutrition in individual adults. Research on these basic issues is essential before we can give definite answers to the questions about relationships between nutrition and aging.