Healthy ageing: what role does metabolism play?

The process of ageing is associated with progressive metabolic remodelling, which mainly affects anthropometric, endocrine and metabolic parameters. Although it occurs successfully in some individuals, in others it fails. Centenarians in good health are a very select group of subjects representing an exceptional condition. How centenarians achieve an extended human lifespan is not known. In order to assess the relationship between healthy ageing and metabolism, age-related metabolic changes in elderly subjects have been studied using different techniques in both animals and humans. Several studies in humans have shown that longevity is associated with significantly improved glucose handling — primarily a rise in insulin sensitivity and a decline in plasma insulin-like growth factor-I. Calorie restriction seems to be the best positive modulator of metabolism favouring longevity. In addition, specific metabolic adaptations — possibly genetic — may occur in those reaching healthy, extreme old age.