Lifestyle interventions to prevent cognitive impairment, dementia and Alzheimer disease

Research into dementia prevention is of paramount importance if the dementia epidemic is to be halted. Observational studies have identified several potentially modifiable risk factors for dementia, including hypertension, dyslipidaemia and obesity at midlife, diabetes mellitus, smoking, physical inactivity, depression and low levels of education. Randomized clinical trials are needed that investigate whether interventions targeting these risk factors can reduce the risk of cognitive decline and dementia in elderly adults, but such trials are methodologically challenging. To date, most preventive interventions have been tested in small groups, have focused on a single lifestyle factor and have yielded negative or modest results. Given the multifactorial aetiology of dementia and late-onset Alzheimer disease, multidomain interventions that target several risk factors and mechanisms simultaneously might be necessary for an optimal preventive effect. In the past few years, three large multidomain trials (FINGER, MAPT and PreDIVA) have been completed. The FINGER trial showed that a multidomain lifestyle intervention can benefit cognition in elderly people with an elevated risk of dementia. The primary results from the other trials did not show a statistically significant benefit of preventive interventions, but additional analyses among participants at risk of dementia showed beneficial effects of intervention. Overall, results from these three trials suggest that targeting of preventive interventions to at-risk individuals is an effective strategy. This Review discusses the current knowledge of lifestyle-related risk factors and results from novel trials aiming to prevent cognitive decline and dementia. Global initiatives are presented, including the World Wide FINGERS network, which aims to harmonize studies on dementia prevention, generate high-quality scientific evidence and promote its implementation.Prevention of dementia through moderation of risk factors presents a promising strategy to counter the rising dementia epidemic. In this Review, Kivipelto and colleagues discuss lifestyle-related risk factors for dementia, results from clinical trials of lifestyle interventions and new multinational initiatives that aim to identify and test effective dementia prevention strategies.Key pointsCognitive impairment, dementia and Alzheimer disease (AD) are multifactorial and complex conditions with several potentially modifiable risk factors including vascular and lifestyle factors.Owing to the multifactorial aetiology of dementia and AD, multidomain interventions that target several risk factors and mechanisms simultaneously might be needed for effective prevention.The first large randomized controlled trials of multidomain lifestyle interventions to prevent cognitive impairment have been completed, and the results suggest that targeting interventions to individuals at risk of dementia is an effective strategy.A life-course approach is needed to facilitate optimal lifestyle intervention strategies for different age groups and for individuals with different risk profiles.Identification of interventions that are effective and sustainable in different geographic, economic and cultural settings should be the focus of future research.