The built environment and cognitive disorders: Results from the Cognitive Function and Ageing Study II

Introduction: Features of built environment have been related to behavior modification and might stimulate cognitive activity with a potential impact on cognitive health in later life. The aim of this study is to investigate cross-sectional associations between features of land use, cognitive impairment and dementia and also explore urban and rural differences in these associations.

Methods: Postcodes of the 7505 community-based participants (age 65+) in the Cognitive Function and Ageing Study II (collected in 2008–2011) were linked to environmental data from government statistics. A multilevel logistic regression was used to investigate associations between cognitive impairment (defined as MMSE≤25), dementia (GMS-AGECAT organicity level≥3) and land use features, including natural environment availability and land use mix, fitting interaction terms with three rural/urban categories. Data were analyzed in 2015.

Results: Associations between features of land use and cognitive impairment were not linear. After adjusting for individual-level factors and area deprivation, living in areas with high land use mix was associated with a nearly 30% decreased odds of cognitive impairment (OR: 0.72; 95%CI: 0.58, 0.89). This was similar, yet non-significant, for dementia (OR: 0.70; 95%CI: 0.46, 1.06). In urban conurbations, living in areas with high natural environment availability was associated with
30% reduced odds of cognitive impairment (OR: 0.70; 95%CI: 0.50, 0.97).

Conclusions: Non-linear associations between features of land use and cognitive impairment were confirmed in this new cohort of older people in England. Both a lack and overload of environmental stimulation may be detrimental to cognition in later life.