Developmental aspects of a life course approach to healthy ageing

We examine the mechanistic basis and wider implications of adopting a developmental perspective on human ageing. Previous models of ageing have concentrated on its genetic basis, or the detrimental effects of accumulated damage, but also have raised issues about whether ageing can be viewed as adaptive itself, or is a consequence of other adaptive processes, for example if maintenance and repair processes in the period up to reproduction are traded off against later decline in function. A life course model places ageing in the context of the attainment of peak capacity for a body system, starting in early development when plasticity permits changes in structure and function induced by a range of environmental stimuli, followed by a period of decline, the rate of which depends on the peak attained as well as the later life conditions. Such path dependency in the rate of ageing may offer new insights into its modification. Focusing on musculoskeletal and cardiovascular function, we discuss this model and the possible underlying mechanisms, including endothelial function, oxidative stress, stem cells and nutritional factors such as vitamin D status. Epigenetic changes induced during developmental plasticity, and immune function may provide a common mechanistic process underlying a life course model of ageing. The life course trajectory differs in high and low resource settings. New insights into the developmental components of the life course model of ageing may lead to the design of biomarkers of later chronic disease risk and to new interventions to promote healthy ageing, with important implications for public health. The life course model of ageing showing average hypothetical trajectories of functional capacity for organs and systems in individuals from low (red) and high (blue) income settings. Low income settings are associated with a poorer start to life in terms of inherited health capital. Functional capacity develops more slowly in a low income setting, but reaches a lower peak capacity earlier in the life course. Throughout life the environmental challenges to function are likely to be greater in the low income setting, leading to faster and earlier decline. In addition, an acute challenge such as an accident or infection in mid‐life may produce a dip in function followed by recovery in a high income setting, but a drastic loss of function in a low income setting (dashed red line). Provision of personal care, most often in high income settings, ca