Calorie Restriction in Nonhuman and Human Primates

Publisher Summary Scientific data on the health effects of calorie restriction (CR) with adequate nutrition in humans has accumulated and is presented in this chapter. Data from animal studies show that CR without malnutrition, i.e., with an adequate intake of essential nutrients, promotes health and longevity. It seems highly unlikely that data on the effects of severe (i.e., 25 to 30%) CR on aging will ever be obtained from randomized clinical studies on humans because of an inability to obtain compliance and funding. However, data on the effects of relatively short-term CR in humans has accumulated from epidemiological and observational studies of unintentional induced CR and from randomized studies lasting 6 to 12 months. It is known that in both nonhuman and human primates CR with adequate nutrition protects against obesity, type 2 diabetes, and cardiovascular diseases, which are leading causes of morbidity and mortality. Cancer incidence and mortality seem also to be reduced in CR monkeys and studies of CR humans reveal a consistent reduction in metabolic factors associated with increased cancer risk. Nonetheless, nothing is known about the long-term effects of CR on the age associated increased risk of bone fractures, immune deficiencies, and dementia or on the rate of aging in nonhuman and human primates. More studies are needed to elucidate the molecular mechanisms underlying the beneficial effects of CR in nonhuman and human primates and to characterize new markers of aging/longevity that can assist scientists and clinicians in predicting mortality and morbidity.