CALORIC RESTRICTION INCREASES HDL2 LEVELS IN RHESUS-MONKEYS (MACACA-MULATTA)

Caloric restriction (CR) prolongs the life of rodents and other small animals, but the benefits of CR for primates and people are as yet unk nown, and mechanisms by which CR may slow aging remain unidentified. A study of rhesus monkeys, Macaca mulatta, is underway to determine if CR might prolong life span in primates and to evaluate potential mecha nisms for Life prolongation. Thirty rhesus monkeys in three age cohort s, restricted to 70% of ad libitum calorie intake for 6-7 yr, were com pared with 30 controls. Plasma lipid, lipoprotein, and high-density li poprotein (HDL) apolipoproteins and subfractions were measured and com pared with weight, percent fat; glucose, and insulin level. CR caused decreased triglyceride levels in adult-monkeys and increased levels of HDL2b, the HDL subfraction associated with protection from atheroscle rosis. Multivariate statistical analyses showed that differences in li pid and lipoprotein levels occurring with CR could be accounted for, a t least in part; by decreased body mass and improved glucose regulatio n. These studies have used a novel dietary modification paradigm in no nhuman primates focused on calorie reduction. Results suggest that CR, as mediated by its beneficial effect on body composition and glucose metabolism, could prolong human life by decreasing the incidence of at herosclerosis.