Dietary restriction and aging in rhesus monkeys: the University of Wisconsin study

Dietary restriction (DR) retards aging and extends the maximum lifespan of laboratory mice and rats. To determine whether DR has similar actions in a primate species, we initiated a study in 1989 to investigate the effects of a 30% DR in 30 adult male rhesus monkeys. In 1994, an additional 30 female s and 16 males were added to the study. Although the animals are still midd le-aged, a few differences have developed between the control and DR animal s suggesting that DR may induce physiologic changes in the rhesus monkey si milar to those observed in rodents. Fasting basal insulin and glucose conce ntrations are lower in DR compared to control animals while insulin sensiti vity is higher in the restricted animals. DR has also altered circulating L DL in a manner that may inhibit atherogenesis. These results suggest that D R may be slowing some age-related physiologic changes. In addition to measu res of glucose and lipid metabolism, the animals are evaluated annually for body composition, energy expenditure, physical activity, hematologic indic es, and blood or urinary hormone concentrations. In the next few years, the first animals will reach the average lifespan (similar to 26 years) of cap tive rhesus monkeys and it will become possible to determine if DR retards the aging process and extends the lifespan in a primate species. (C) 2000 E lsevier Science Inc. All rights reserved.