Objectively measured environmental features and their association with cognition and dementia: a systematic review and meta-analysis

Linlin Da; Xia Song; Zimu Jia; Nicholas Gary Lamont Myers; Jin Sun; Jingkai Wei; Daniel Jung; Feiyang Li; Suhang Song

doi:10.1016/j.arr.2024.102630

Objectively measured environmental features and their association with cognition and dementia: a systematic review and meta-analysis

Ageing Res Rev. 2024 Dec 7:102630. doi: 10.1016/j.arr.2024.102630. Online ahead of print.

Authors

Linlin Da¹, Xia Song², Zimu Jia³, Nicholas Gary Lamont Myers⁴, Jin Sun⁵, Jingkai Wei⁶, Daniel Jung¹, Feiyang Li¹, Suhang Song⁷

Affiliations

¹ Department of Health Policy and Management, College of Public Health, University of Georgia, Athens, GA, USA, 30602.
² Department of Traditional Chinese Medicine and Rehabilitation, The Fifth People's Hospital of Jinan, Jinan, Shandong, China, 250000.
³ School of Education, John Hopkins University, Baltimore, MD, USA, 21209.
⁴ Honors College, University of Georgia, Athens, GA, USA, 30602.
⁵ School of Computing, University of Georgia, Athens, GA, USA, 30602.
⁶ Department of Family and Community Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA, 77030.
⁷ Department of Health Policy and Management, College of Public Health, University of Georgia, Athens, GA, USA, 30602. Electronic address: Suhang.song@uga.edu.

PMID: 39653153
DOI: 10.1016/j.arr.2024.102630

Abstract

Dementia affects millions of people worldwide. Since effective treatments are still lacking, it is important to identify factors that may help prevent dementia. Recent studies suggest environmental factors may affect dementia risk, but findings are inconsistent and often rely on subjective measures. This study evaluated the association between objectively measured environmental factors, such as air pollution and built environment features, and the risk of dementia and cognitive decline. We systematically reviewed studies that employed objective measures of environmental factors and reported their association with dementia risk and cognitive decline. Meta-analysis was performed to synthesize data on environmental exposures and the onset of dementia. Air pollution exposure was linked to higher dementia risk (PMx risk ratio 1.09; 95% CI 1.06,1.12) (NOx risk ratio 1.10; 95% CI 1.01,1.20) and cognitive decline, while exposure to park areas or green/blue spaces was generally associated with reduced dementia risk (risk ratio 0.94; 95% CI 0.92,0.96) and slower cognitive decline. Living closer to major roads increased the risk of dementia (risk ratio 1.10; 95% CI 1.06,1.13), and cognitive impairment. Street layouts with better connectivity and walkability are associated with a reduced risk of cognitive impairment. Access to local amenities, such as food stores, community centers, and healthcare amenities, supports cognitive health. These findings underscore the importance of considering environmental factors in dementia prevention and highlight the need for further research to clarify the role of urban design in supporting cognitive health.

Keywords: Cognition; Dementia; Environmental features; Objective measurement.

Publication types

Review