NUTRITION FACTORS IN RELATION TO CELLULAR AND REGULATORY IMMUNE VARIABLES IN A FREE-LIVING ELDERLY POPULATION

Aging is associated with a greater susceptibility to nutrition deficiencies and to progressive senescence of the immune system. To test whether nutrition status contributes to the immunologic changes observed in elderly individuals, we examined the relationship between nutrition status and in vitro indices of immune responses in 82 healthy, free-living elderly individuals. Nutrition status was assessed by anthropometric measurements, 7 d food records, and blood concentrations of selected nutrients. Using regression analyses, we found that none of the nutrition factors was associated with cytotoxic activity of natural killer (NK) cells against the leukemic cell line K562. However, our results suggest that the dietary intakes of vitamins E and D negatively influenced the activity of interleukin 2 (IL-2) measured by a bioassay in which the CTLL cell line was used. An association may exist between particular aspects of nutrition status and regulation of immune response by IL-2. The need for further studies is emphasized.