Approved Research
The impact of environment and pollution on cognitive function and dementia in older adults in the UK
Lay summary
Dementia, a syndrome related to a decline in cognitive function and loss of functional ability, has been recognised to be a critical issue in the UK. To develop strategies for reducing the risk of cognitive decline and dementia, a large body of research has identified several lifestyle factors that maintain cognitive function and health status (e.g., physical activity and social interaction), and some chronic conditions with detrimental effects on cognitive function (e.g., hypertension and diabetes). Since several characteristics of the environment (e.g., green spaces, air pollution, access to public transport) have been found to play a key role in influencing health behaviours and prevention of obesity and non-communicable diseases, it is important to investigate the potential impact of different environmental factors on cognitive health in older age.
Recent studies have suggested that vibrant, high-density, destination-rich neighbourhood environments can provide opportunities for older residents to engage in physical, social and mental activities that benefit cognitive health. However, such environments are also associated with harmful levels of air pollution and noise, which are found to have a negative influence on cognitive decline and dementia. To understand these complex and interacting factors in the environments and their joint impact on cognitive health, it is important to examine the complicated relationships between multiple environmental factors and identify key environmental factors that reduce the acceleration of cognitive decline and prevent the development of dementia.
To address these knowledge gaps, the aim of this study is to investigate the complex impact of the built environment, the natural environment and pollution on cognitive function and incident dementia in older age. Using the UK Biobank data, this study will use statistical analytical methods to investigate (1) how different environmental factors can influence cognitive decline and dementia in older people; (2) how lifestyle behaviours (physical activity, social support) can explain the impact of environmental factors on cognitive health; (3) whether the effects of environmental factors vary across subgroups of sex, socioeconomic status and genetic predisposition. The findings of this study will contribute to knowledge that will advance research on environment, cognition and ageing and enhance evidence-based strategies to develop environmental interventions and reduce the risk of cognitive decline and dementia.