Effects of Long-Term Diet Restriction on Aging and Longevity in Primates Remain Uncertain

DIET restriction (DR) remains the only reproducible, nongenetic intervention for alteration of aging processes including extension of average and maximal life span, prevention and/or amelioration of many age-related diseases, and maintenance of more youthful physiological function later into life. A substantial literature has made it clear that these effects of DR are observed in nearly all species in which it has been tested (1,2). Despite this impressive body of experimental results, it remains unknown whether DR can impact positively upon human aging. Indeed, whether DR is relevant to human aging remains one of the most significant unanswered questions in contemporary biogerontology. Nonhuman primates have long been used as models for human disease including aging (3,4). To this end, the recent article by Bodkin and colleagues (5) reporting on age-related morbidity and mortality in rhesus monkeys and the putative beneficial effects of DR provides an interesting, though preliminary, assessment of the possible relevance of reduced calorie intake to human aging.