Optimizing cognition in older adults: lifestyle factors, neuroplasticity, and cognitive reserve

Ageing is a physiological condition, characterized by multiple changes in the environment and in sensory, motor, and cognitive functions. There is considerable variance in the degree of cognitive decline associated with non-pathological ageing, with some individuals maintaining strikingly effective intellectual abilities even beyond their nineties. While some of the factors associated with graceful ageing seem to be linked to the individual genetic endowment or to aspects of childhood and youth experience, such as education, others are linked to chronic disease states and lifestyle factors. These include nutritional intake, smoking status, physical activity, and being engaged in cognively stimulating activities. Importantly, many of these factors and even chronic disease status could be modifiable even in middle or old age to promote a successful ageing. According to Norton et al. (2014), a third of Alzheimer’s disease cases worldwide are estimated to be attributable to seven modifiable factors (see Table 166.1), some of which could be modified even in mid and late life. In this chapter, we shall outline the human and animal literature which has provided evidence for the effects and mechanisms of action of lifestyle protective factors on age-related cognitive decline and on age-related neurodegenerative dementia, concentrating on physical activity and cognitive activity, and the paradigm of Enriched Environment. We will also describe the core lifestyle effects on cognitive ageing, including neural plasticity and the action of multiple molecular factors, which translate physical and cognitive activity into adaptive and protective changes in the brain.