In vitro oxidation of low-density lipoprotein in two species of nonhuman primates subjected to caloric restriction

Caloric restriction (CR), which increases longevity and retards age-associa ted diseases in laboratory rodents, is being evaluated in nonhuman primate trials. CR reduces oxidative stress in rodents and appears to improve risk factors for cardiovascular disease in nonhuman primates. We tested the hypo thesis that low-density lipoprotein (LDL) oxidizability is reduced in two m onkey species (rhesus and cynomolgus) subjected to chronic CR. In both spec ies, no significant differences occurred between CR and control animals on total, LDL, or high-density lipoprotein (HDL) cholesterol. In rhesus monkey s, triglycerides were higher in controls than CR (139 +/- 23 vs 66 +/- 8 mg /dl, p < .01, respectively). LDL from CR rhesus monkeys was reduced in trig lyceride content and molecular weight compared to controls, whereas LDL com position in cynomolgus monkeys was similar in CR and control animals. In ke eping with minor deviations in lipids, antioxidants, and LDL composition, n o consistent differences in in vitro LDL oxidizability were apparent betwee n CR and controls in either species.