Neighborhood built environment and cognition in non-demented older adults: The Multi-Ethnic Study of Atherosclerosis

Perceived but not objective measures of neighborhood safety and food environments are associated with longitudinal changes in processing speed among urban older adults

BACKGROUND

Although a growing body of literature documents the importance of neighborhood effects on late-life cognition, little is known about the relative strength of objective and subjective neighborhood measures on late-life cognitive changes. This study examined effects of objective and subjective neighborhood measures in three neighborhood domains (neighborhood safety, physical disorder, food environments) on longitudinal changes in processing speed, an early marker of cognitive aging and impairment.

METHODS

The analysis sample included 306 community-dwelling older adults enrolled in the Einstein Aging Study (mean age = 77, age range = 70 to 91; female = 67.7%; non-Hispanic White: 45.1%, non-Hispanic Black: 40.9%). Objective and subjective measures of neighborhood included three neighborhood domains (i.e., neighborhood safety, physical disorder, food environments). Processing speed was assessed using a brief Symbol Match task (unit: second), administered on a smartphone device six times a day for 16 days and repeated annually for up to five years. Years from baseline was used as the within-person time index.

RESULTS

Results from mixed effects models showed that subjective neighborhood safety (β= -0.028) and subjective availability of healthy foods (β= -0.028) were significantly associated with less cognitive slowing over time. When objective and subjective neighborhood measures were simultaneously examined, subjective availability of healthy foods remained significant (β= -0.028) after controlling for objective availability of healthy foods. Associations of objective neighborhood crime and physical disorder with processing speed seemed to be confounded by individual-level race and socioeconomic status; after controlling for these confounders, none of objective neighborhood measures showed significant associations with processing speed.

CONCLUSION

Subjective neighborhood safety and subjective availability of healthy foods, rather than objective measures, were associated with less cognitive slowing over time over a five-year period. Perception of one's neighborhood may be a more proximal predictor of cognitive health outcomes as it may reflect one's experiences in the environment. It would be important to improve our understanding of both objective and subjective neighborhood factors to improve cognitive health among older adults.

Associations of Subjective Memory with Life Space and Neighborhood Built Environment in Older Adults in the ACTIVE Study

Objectives: To investigate the longitudinal association of life space and neighborhood and built environment (NBE) with subjective memory among individuals 65 and older, and the mediating role of depressive symptoms, a major correlate of life space mobility, NBE, and subjective memory. Methods: We examined community-dwelling participants in the Advanced Cognitive Training for Independent and Vital Elderly study (N = 2,622, Mean age = 73.7 years, 24.9% Black) across annual assessments of up to 3 years. Results: Baseline life space and NBE were positively associated with subjective memory, and these associations were partly mediated by depressive symptoms. Over time, higher baseline life space predicted a better subjective memory as one aged. Life space was concurrently associated with subjective memory across time, mediated by concurrent depressive symptoms. Discussion: Potentially modifiable environmental factors such as life space and NBE appear to influence level and change in subjective memory as we age. Interventions supporting movement in our environments may help offset subjective memory problems, a potential early sign of dementia.

A Scoping Review of Neighborhoods and Cognitive Health Disparities Among US Midlife and Older Adults

Objectives: The neighborhood environment may be an important determinant of racial/ethnic disparities in cognitive function. To understand how neighborhoods are linked to cognition across racial/ethnic groups, this scoping review organizes research investigating relationships between multiple neighborhood domains and cognitive function in diverse samples of US midlife and older adults. Methods: PubMed/MEDLINE, Web of Science, and CAHL were used to extract quantitative disparities-focused studies (n = 17) that included US adults ages 50+, racial/ethnic minoritized populations, cognitive dependent variable(s), and neighborhood-level independent variable(s) published from January 2010 to October 2021. Results: Studies demonstrate variation within and between racial/ethnic groups in how neighborhood factors are associated with cognition. Economically and socially advantaged neighborhoods were associated with better cognition. Findings were mixed for built and neighborhood composition measures. Discussion: More research with greater racial/ethnic representation is needed to disentangle which aspects of the neighborhood are most salient for specific cognitive function domains across diverse populations.

Effects of neighborhood built environment on cognitive function in older adults: a systematic review

BACKGROUND

In the background of an aging population, the risk of cognitive impairment in the older population is prominent. Exposure to complex neighborhood built environments may be beneficial to the cognitive health of older adults, and the purpose of this study was to systematically review the scientific evidence on the effects of neighborhood built environments on cognitive function in older adults.

METHODS

Keywords and references were searched in Web of Science, Pubmed, PsycINFO, and MEDLINE. Studies examining the relationship between the built environment and cognitive function in older adults were included. The neighborhood built environment as an independent variable was classified according to seven aspects: density, design, diversity, destination accessibility, public transportation distance, blue/green space, and built environment quality. The cognitive function as the dependent variable was classified according to overall cognitive function, domain-specific cognitive function, and incidence of dementia. The quality of the included literature was assessed using the National Institutes of Health's Observational Cohort and Cross-Sectional Study Quality Assessment Tool.

RESULTS

A total of 56 studies were included that met the inclusion criteria, including 31 cross-sectional studies, 23 longitudinal studies, 1 cross-sectional study design combined with a case-control design, and 1 longitudinal study design combined with a case-control design. Most of the studies reviewed indicate that the built environment factors that were positively associated with cognitive function in older adults were population density, street connectivity, walkability, number of public transportation stops around the residence, land use mix, neighborhood resources, green space, and quality of the neighborhood built environment. Built environment factors that were negatively associated with cognitive function in older adults were street integration, distance from residence to main road. The relationship between residential density, destination accessibility, and blue space with cognitive function in older adults needs to be further explored.

CONCLUSION

Preliminary evidence suggests an association between the neighborhood built environment and cognitive function in older adults. The causal relationship between the built environment and cognitive function can be further explored in the future using standardized and combined subjective and objective assessment methods, and longitudinal or quasi-experimental study designs. For public health interventions on the cognitive health of older adults, it is recommended that relevant authorities include the neighborhood built environment in their intervention programs.

The effects of neighborhood socioeconomic status on ADL/IADL among Chinese older adults-neighborhood environments as mediators

Background

There have been few consistencies in the effects and pathways of neighborhood socioeconomic status (SES) on functional limitations. This study aimed to investigate whether neighborhood socioeconomic status influences ADL/IADL in older residents in China through the neighborhood built environment and social environment.

Methods

Activities of daily living/IADL were assessed in a sample of 5,887 Chinese individuals aged 60 or older, utilizing data obtained from the 2011 China Health and Retirement Longitudinal Study (CHARLS 2011). Neighborhood SES was measured by the neighborhood per-capita net income. Neighborhood built environment was measured by the security resources, motion resources, living resources, service resources for older adults, and medical resources of neighborhood. Neighborhood social environment was measured by the organizations, unemployment subsidies, minimum living allowance, subsidies to persons older than 65, and pensions to persons older than 80 of the neighborhood. The two-level logistical regression model and multilevel structural equation model (MSEM) were used.

Results

The rate of ADL/IADL loss among Chinese older adults aged 60 and above in 2011 were 32.17 and 36.87%, respectively. Neighborhood SES was significantly associated with ADL/IADL in older adults. Compared with the respondents living in communities with lower SES, those living in communities with higher SES possessed better ADL (β = -0.33, p < 0.05) and IADL (β = -0.36, p < 0.05) status. The path of neighborhood socioeconomic status on ADL was completely mediated by the neighborhood built environment (β = -0.110, p < 0.05) and neighborhood social environment (β = -0.091, p < 0.05). Additionally, the effect of neighborhood socioeconomic status on IADL was fully mediated by the neighborhood built environment (β = -0.082, p < 0.05) and neighborhood social environment (β = -0.077, p < 0.05).

Conclusion

Neighborhood SES was significantly correlated with ADL/IADL through the neighborhood environment. Improving the ADL/IADL status of older adults residing in low socioeconomic neighborhoods requires enhancing the built and social environment by provisioning additional neighborhood resources.

Community-Based Strategies to Reduce Alzheimer's Disease and Related Dementia Incidence Among Rural, Racially/Ethnically Diverse Older Adults

Purpose of Review

The purpose of this paper was to address the research question "What recent advances in Alzheimer's Disease and Related Dementias (ADRD) risk reduction strategies can be tailored for rural, racially/ethnically diverse populations?" A rural resident's life story that grounded the work is shared. Next, a brief description is provided regarding ADRD risk factors of importance in rural, multicultural settings. Gaps in U.S.-based research are highlighted. Policy actions and interventions that may make a difference in alleviating rural, ADRD-related disparities are offered.

Recent Findings

More than a dozen factors, including lack of built environment, periodontitis, poor air quality, and sensory loss, were identified that are of particular relevance to rural groups. Evidence of importance to underserved residents has also emerged regarding the harmful effects of ultra-processed foods on brain health, benefits of even minimal physical activity, and importance of social engagement, on brain health.

Summary

Resident-led initiatives will be key to creating change at the community level. Health providers are also called to assist in identifying and adapting culturally specific upstream approaches, in partnership with community stakeholders. These mechanisms are vital for decreasing ADRD burdens in underserved communities facing the largest disparities in preventive care.

Neighborhood resources and risk of cognitive decline among a community-dwelling long-term care population in the U.S

Objective

To examine the associations between neighborhood resources (i.e., number of restaurants, recreation centers, or social services for seniors and persons with disability per land area) and cognitive decline among a community-dwelling long-term care population and whether they differ by baseline cognition status.

Study design

Prospective longitudinal cohort study.

Methods

We used a longitudinal dataset that assessed over a two-year period older adults receiving state-funded home- and community-based services in Michigan Metropolitan areas (N = 9,802) and applied nonlinear mixed models with a random intercept with Poisson distribution.

Results

Cognitively intact older adults were less likely to experience cognitive decline when they resided in resource-rich neighborhoods, compared to those cognitively intact but living in neighborhoods that lacked resources. But their cognitively impaired or dementia-diagnosed counterparts did not similarly benefit from living in neighborhoods with rich resources.

Conclusions

Neighborhood resources may be an important aspect of intervention to mitigate cognitive decline before older adults become cognitively impaired.

Neighborhood Built Environments and Health in Later Life: A Literature Review

Objectives: This literature review aims to assess the current state of the field linking neighborhood environments to later-life health and wellbeing. Methods: We used electronic databases (e.g., PubMed, Google Scholar, and ProQuest) to search for studies published between 2010 and 2022 examining associations between neighborhood built environmental variables and later-life physical, cognitive, mental, and social health outcomes. Results: Among 168 studies reviewed, the majority were quantitative (n = 144) and cross-sectional (n = 122). Neighborhood environmental variables significantly associated with later-life health outcomes included population density/rurality, walkability/street connectivity, access to services and amenities, neighborhood quality and disorder, and parks/green/blue/open space. Neighborhoods operated through behavioral and biological pathways including hazardous exposures, affective states (e.g., stress and restoration), and lifestyle (e.g., exercise, socialization, and diet). Discussion: Neighborhoods and healthy aging research is a burgeoning interdisciplinary and international area of scholarship. Findings can inform upstream community interventions and strengthen clinical care.

Neighborhood-level social vulnerability and individual-level cognitive and motor functioning over time in older non-Latino Black and Latino adults

Introduction

Despite known health disparities in cognitive aging, a comprehensive rationale for the increased burden in older minoritized populations including non-Latino Black and Latino adults has yet to be elucidated. While most work has focused on person-specific risk, studies are increasingly assessing neighborhood-level risk. We evaluated multiple aspects of the environmental milieu that may be critical when considering vulnerability to adverse health outcomes.

Methods

We investigated associations between a Census-tract derived Social Vulnerability Index (SVI) and level of and change in cognitive and motor functioning in 780 older adults (590 non-Latino Black adults, ∼73 years old at baseline; 190 Latinos, ∼70 years old baseline). Total SVI scores (higher = greater neighborhood-level vulnerability) were combined with annual evaluations of cognitive and motor functioning (follow-up ranged from 2 to 18 years). Demographically-adjusted mixed linear regression models tested for associations between SVI and cognitive and motor outcomes in analyses stratified by ethno-racial group.

Results

For non-Latino Black participants, higher SVI scores were associated with lower levels of global cognitive and motor functioning-specifically, episodic memory, motor dexterity and gait-as well as longitudinal change in visuospatial abilities and hand strength. For Latinos, higher SVI scores were associated with lower levels of global motor functioning only-specifically, motor dexterity; there were no significant associations between SVI and change in motor functioning.

Discussion

Neighborhood-level social vulnerability is associated with cognitive and motor functioning in non-Latino Black and Latino older adults, although associations appear to contribute to level more so than longitudinal change.

Perceptions of greenspace and social determinants of health across the life course: The Life Course Sociodemographics and Neighborhood Questionnaire (LSNEQ)

We developed the Life Course Sociodemographics and Neighborhood Questionnaire (LSNEQ) to query older adults about perceived neighborhood greenspaces across the life course (i.e., distance to park, number of neighborhood parks/playgrounds, and neighborhood greenness) and about characteristics hypothesized to confound or moderate/mediate greenspace-health associations. Six perceived life course indices are derived from the LSNEQ: neighborhood socioeconomic status, neighborhood walking/biking, urbanicity, neighborhood amenities, neighborhood park access, and neighborhood greenness. Older adults from St. Louis, Missouri, and Sacramento, California, completed the LSNEQ in 2020-2021. The indices demonstrated borderline acceptable to good internal consistency (alpha = 0.60-0.79) and good to excellent test-retest reliability (ICC = 0.71-0.96) and detected different patterns of park access and neighborhood greenness by racialized group and location. Individuals with index scores indicating more neighborhood walking/biking and greater presence of neighborhood amenities over their life course were more likely to report neighborhood-based walking in older age. Overall, the LSNEQ is a reliable instrument to assess perceptions of life course social determinants of health including neighborhood greenspaces.

Neighborhood segregation and cognitive change: Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

We investigated associations between neighborhood racial/ethnic segregation and cognitive change.

METHODS

We used data (n = 1712) from the Multi-Ethnic Study of Atherosclerosis. Racial/ethnic segregation was assessed using Getis-Ord (Gi*) z-scores based on American Community Survey Census tract data (higher Gi* = greater spatial clustering of participant's race/ethnicity). Global cognition and processing speed were assessed twice, 6 years apart. Adjusted multilevel linear regression tested associations between Gi* z-scores and cognition. Effect modification by race/ethnicity, income, education, neighborhood socioeconomic status, and neighborhood social support was tested.

RESULTS

Participants were on average 67 years old; 43% were White, 11% Chinese, 29% African American/Black, 17% Hispanic; 40% had high neighborhood segregation (Gi* > 1.96). African American/Black participants with greater neighborhood segregation had greater processing speed decline in stratified analyses, but no interactions were significant.

DISCUSSION

Segregation was associated with greater processing speed declines among African American/Black participants. Additional follow-ups and comprehensive cognitive batteries may further elucidate these findings.

HIGHLIGHTS

A study of neighborhood racial/ethnic segregation and change in cognition. Study was based on a racially and geographically diverse, population-based cohort of older adults. Racial/ethnic segregation (clustering) was measured by the Getis-ord (Gi*) statistic. We saw faster processing speed decline among Black individuals in segregated neighborhoods.

Neighborhood built environments and cognition in later life

Objectives: Maintaining good cognition is crucial in later life. However, most existing research has focused on individual factors impacting cognition, and few studies have investigated the association between neighborhood built environment and older adults' cognition. This study examined the association between neighborhood built environment and cognition among community-dwelling older adults and identified variations in this association between different age groups in the older population.Methods: Data were derived from a cross-sectional survey of 1873 people aged 65 years and above in Hong Kong. We merged individual data from the survey with neighborhood built environment data based on community auditing and geographical information system. After controlling for individual covariates, we used multivariable linear regression to examine the association between neighborhood built environment and cognition.Results: Residents aged 80 and younger in neighborhoods with a higher land-use mix and more public transport terminals exhibited better cognition. Only the number of community centers in a neighborhood was positively associated with cognition for people older than 80.Conclusion: The built environment creates diverse impacts on different age groups among older adults. Our findings provide useful information for urban planners and policymakers for planning community facilities and built environments that consider the needs of different age groups within the older population.

Neighborhood 'Disamenities': local barriers and cognitive function among Black and white aging adults

BACKGROUND

This study examined the association between cognitive function and three neighborhood 'disamenities' that may pose local barriers to utilizing community resources and increase risk for cognitive decline.

METHOD

Using national data from 21,165 urban- and suburban-dwelling Black and white adults (mean age: 67 years) in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, we assessed global cognitive function through a factor score of five cognitive screening tests. General Additive Mixed Models (GAMM) tested whether residing in areas with more polluting sites, highways, and limited walkability was associated with worse cognitive function.

RESULTS

Limited walkability and the presence of polluting sites had a significant negative association with cognitive function after controlling for individual and neighborhood factors.

CONCLUSION

Neighborhood disamenities may be linked to cognitive function among aging residents. Identifying neighborhood factors that pose barriers to accessing community resources may inform upstream policy applications to reduce risk for cognitive decline.

Neighbourhood walkability in relation to cognitive functioning in patients with disorders along the heart-brain axis

This study examined associations of neighbourhood walkability with cognitive functioning (i.e., global cognition, memory, language, attention-psychomotor speed, and executive functioning) in participants without or with either heart failure, carotid occlusive disease, or vascular cognitive impairment. Neighbourhood walkability at baseline was positively associated with global cognition and attention-psychomotor speed. These associations were stronger in patients with vascular cognitive impairment. Individuals who live in residential areas with higher walkability levels were less likely to have impairments in language and executive functioning at two-year follow-up. These findings highlight the importance of the built environment for cognitive functioning in healthy and vulnerable groups.

Longitudinal neighbourhood determinants with cognitive health and dementia disparities: protocol of the Multi-Ethnic Study of Atherosclerosis Neighborhoods and Aging prospective cohort study

INTRODUCTION

The burden of Alzheimer's disease (AD) and AD-related dementias (ADRD) is increasing nationally and globally, with disproportionate impacts on lower-income, lower education and systematically marginalised older adults. Presence of inequalities in neighbourhood factors (eg, social context, physical and built environments) may affect risk of cognitive decline and be key for intervening on AD/ADRD disparities at the population level. However, existing studies are limited by a dearth of longitudinal, detailed neighbourhood measures linked to rich, prospective cohort data. Our main objective is to identify patterns of neighbourhood change related to prevalence of-and disparities in-cognitive decline and dementia.

METHODS AND ANALYSES

We describe the process of collecting, processing and linking extensive neighbourhood data to the Multi-Ethnic Study of Atherosclerosis (MESA), creating a 25+ years dataset. Within the MESA parent study, the MESA Neighborhoods and Aging cohort study will characterise dynamic, longitudinal neighbourhood social and built environment variables relevant to cognition for residential addresses of MESA participants. This includes administering new surveys, expanding residential address histories, calculating new measures derived from spatial data and implementing novel deep learning algorithms on street-level imagery. Applying novel statistical techniques, we will examine associations of neighbourhood environmental characteristics with cognition and clinically relevant AD/ADRD outcomes. We will investigate determinants of disparities in outcomes by socioeconomic position and race/ethnicity and assess the contribution of neighbourhood environments to these disparities. This project will provide new evidence about pathways between neighbourhood environments and cognitive outcomes, with implications for policies to support healthy ageing.

ETHICS AND DISSEMINATION

This project was approved by the University of Washington and Drexel University Institutional Review Boards (protocols #00009029 and #00014523, and #180900605). Data will be distributed through the MESA Coordinating Center. Findings will be disseminated in peer-reviewed scientific journals, briefs, presentations and on the participant website.

Cognability: An Ecological Theory of neighborhoods and cognitive aging

While a growing body of evidence points to potentially modifiable individual risk factors for dementia, the built and social environments in which people develop and navigate cognitive decline are largely overlooked. This paper proposes a new theoretical concept, Cognability, to conceptualize how supportive an area is to cognitive health among aging residents. Cognability incorporates a constellation of both positive and negative neighborhood features related to physical activity, social interaction and cognitive stimulation in later life. We analyzed data from the REasons for Geographic And Racial Differences in Stroke Study, a national sample of older Black and white adults in the United States (n = 21,151; mean age at assessment = 67; data collected 2006-2017). Generalized additive multilevel models examined how cognitive function varied by neighborhood features. Access to civic and social organizations, recreation centers, fast-food and coffee establishments, arts centers, museums, and highways were significantly associated with cognitive function. Race-, gender-, and education-specific models did not yield substantial improvements to the full-model. Our results suggest that the unequal distribution of amenities and hazards across neighborhoods may help account for considerable inequities observed in cognitive health among older adults. Cognability advances ecological theories of aging through an innovative "whole neighborhood" approach. It aims to identify which specific neighborhood features are most protective of cognitive health among aging adults to inform upstream public health initiatives, community interventions, and policy.

Disorder, networks, and cognition: do social networks buffer the influence of neighborhood and household disorder on cognitive functioning?

OBJECTIVES

To examine whether neighborhood and household disorder matter for cognitive functioning among middle-aged and older adults and whether the disorder-cognition link is moderated by social network resources.

METHOD

Data are drawn from National Social Life, Health, and Aging Project (NSHAP) Wave 2 (N = 3198). Both neighborhood and household were considered as key residential contexts that shape one's social life and health. Exposure to neighborhood and household disorder was measured using interviewer assessments of signs of disorder and decay, including the presence of disrepair, trash, noise, and unpleasant smells such as air pollution, in the buildings and streets in which the respondent lives. Cognitive function was measured using the survey-adapted Montreal Cognitive Assessment (MoCA-SA). Network size, network range, and frequency of interaction among network members were assessed as moderators.

RESULTS

Neighborhood and household disorder were independently associated with cognitive function. However, disorder in the household appeared to have more direct associations with cognitive function than did the neighborhood when both were present. The association between household disorder and cognitive function was mitigated by network size, such that poor housing conditions were associated with lower cognitive function only for those with small social networks.

CONCLUSION

This study suggests a larger network may play a role in minimizing the negative influence of household disorder on cognitive function for middle-aged and older adults. Social policy and intervention aimed at promoting network ties may help reduce further disparities in cognitive function, especially for those vulnerable groups living in a poor-quality household.

Residential Green Space and Cognitive Function in a Large Cohort of Middle-Aged Women

Importance

Green space can decelerate cognitive decline by supporting physical activity, psychological restoration, or reducing exposure to air pollution. However, existing studies on the association of green space with cognitive decline are limited.

Objective

To examine whether residential green space was associated with cognitive function in middle-aged women.

Design, Setting, and Participants

Starting in 1989, the Nurses' Health Study II enrolled 116 429 female nurses aged 25 to 42 years residing in the US. In 2014 to 2016, 40 082 women were invited to complete an online cognitive battery. This cohort study analyzed women who had data on both green space exposure and cognitive measures. Data analysis was conducted from June to October 2021.

Exposures

Residential exposure to green space was assessed using the Normalized Difference Vegetation Index, a satellite-derived indicator of the quantity of ground vegetation. Landsat satellite data at 270-m and 1230-m buffers around each participants' residential addresses in 2013 were used.

Main Outcomes and Measures

In 2014 to 2016, cognitive function was measured using a self-administered online battery, the Cogstate Brief Battery, consisting of 4 tasks measuring psychomotor speed, attention, learning, and working memory; 3 composite scores, averaging together all tasks, psychomotor speed/attention, and learning/working memory, were created. In addition, the study evaluated potential mediators, including air pollution, depression, and physical activity.

Results

The analytical sample included 13 594 women, of whom 13 293 (98%) were White. Mean (SD) age was 61.2 (4.6) years. In models adjusted for age at assessment, race, childhood, adulthood, and neighborhood socioeconomic status, green space was associated with higher scores on the global Cogstate composite (mean difference per IQR in green space, 0.05; 95% CI, 0.02 to 0.07), and psychomotor speed/attention (mean difference in score, 0.05 standard units; 95% CI, 0.02 to 0.08). This difference in scores is similar to the difference observed in women 1 year apart in age in the data. By contrast, there was no association between green space and learning/working memory (mean difference, 0.0300; 95% CI, -0.0003 to 0.0500).

Conclusions and Relevance

These findings suggest that increasing residential green space may be associated with modest benefits in cognition in middle-aged women.

From urban neighbourhood environments to cognitive health: a cross-sectional analysis of the role of physical activity and sedentary behaviours

BACKGROUND

There is a dearth of studies on the effects of the neighbourhood environment on adults' cognitive function. We examined how interrelated aspects of the built and natural neighbourhood environment, including air pollution, correlate with adults' cognitive function, and the roles of physical activity and sedentary behaviours in these associations.

METHODS

We used data from 4,141 adult urban dwellers who participated in the Australian Diabetes, Obesity and Lifestyle 3 study on socio-demographic characteristics, neighbourhood self-selection, physical activity and sedentary behaviours, and cognitive function. Neighbourhood environmental characteristics included population density, intersection density, non-commercial land use mix, and percentages of commercial land, parkland and blue space, all within 1 km residential buffers. We also calculated annual mean concentrations of NO2 and PM2.5. Generalised additive mixed models informed by directed acyclic graphs were used to estimate the total, direct and indirect effects of environmental attributes on cognitive functions and the joint-significance test was used to examine indirect effects via behaviours.

RESULTS

In the total effects models, population density and percentage of parkland were positively associated with cognitive function. A positive association of PM2.5 with memory was also observed. All neighbourhood environmental attributes were directly and/or indirectly related to cognitive functions via other environmental attributes and/or physical activity but not sedentary behaviours. Engagement in transportation walking and gardening frequency partially mediated the positive effects of the neighbourhood environment on cognitive function, while frequency of transportation walking mediated the negative effects.

CONCLUSIONS

In the context of a low-density country like Australia, denser urban environments with access to parkland may benefit residents' cognitive health by providing opportunities for participation in a diversity of activities. A more fine-grained characterisation of the neighbourhood environment may be necessary to tease out the negative and positive impacts of inter-related characteristics of urban neighbourhood environments on cognitive function.

Neighborhood built environment associated with cognition and dementia risk among older adults: A systematic literature review

Cognitive impairment associated with aging is a serious and growing public health problem. This systematic literature review contributes to better understanding the current state of knowledge on the roles of neighborhood environments in supporting cognitive health in later life. Literature search was carried out in 2020 using the seven databases most relevant to the topic. This review was restricted to peer-reviewed observational and quantitative studies that focused on 1) community-dwelling older adults as target populations; 2) neighborhood built environments as independent variables; and 3) cognition or dementia as outcome variables. Thirty-seven studies published between 1989 and 2020 met the inclusion criteria. The neighborhood built environment domains covered in these included urbanity/rurality, land use, neighborhood physical disorder, transportation infrastructure, urban design, and urban nature. Neighborhood resources and green space exposure were most frequently studied and linked to cognition-related outcomes. Neighborhood built environment was shown to be more pertinent to older adults' global cognition, memory, and dementia. Physical activity showed a mediating role between neighborhood built environment and cognition. The effect of neighborhood built environment on cognitive function was stronger among older women and those with disabilities or lower socioeconomic status. Evidence on the relationship between neighborhood built environment and cognition/dementia among older adults is moderate. Our findings highlight the need for more standardized and longitudinal measures of neighborhood built environment and high-sensitivity cognitive tests that capture the specific and relevant domains of cognition, to facilitate further exploration of the mediating and moderating effects of neighborhood built environment with cognition/dementia in older adults. This review offers insights for future research and policy efforts toward creating communities to support cognitive health and aging in place.

Neighborhood active aging infrastructure and cognitive function: A mixed-methods study of older Americans

Physical exercise benefits cognitive functioning and can protect against neurodegeneration. Neighborhood environments may be pivotal to physically active aging, and thus help shape older adults' cognitive function. This mixed-methods study investigated where older adults exercised outside the home, and whether availability of these neighborhood sites was associated with cognitive function. We thematically analyzed qualitative data from semi-structured interviews in 2015 with 125 older adults (mean age = 71) in the Minneapolis (MN) metropolitan area. Results identified nearby public parks, fitness/sports amenities, and walkable destinations as motivators for recreational exercise and active transit among participants. These findings informed quantitative analysis of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national sample of older Black and white Americans (n = 21,151; mean age at assessment = 67; data collected 2006-2017). We used generalized additive multilevel models to examine whether neighborhood features that qualitative participants identified as encouraging physical activity were associated with elevated levels of cognitive function. Results indicated that residing in neighborhoods with greater availability of local parks, access to recreational amenities, and business density was associated with higher levels of cognitive function. We found no evidence to suggest a significant association between availability of these neighborhood resources and rate of cognitive decline. This study identifies specific neighborhood active aging infrastructure that may support cognitive function among older adults aging in place.

Longitudinal Associations between the Neighborhood Built Environment and Cognition in US Older Adults: The Multi-Ethnic Study of Atherosclerosis

Few studies have examined associations between neighborhood built environments (BE) and longitudinally measured cognition. We examined whether four BE characteristics were associated with six-year change in global cognition and processing speed. We obtained data on 1816 participants without dementia from the Multi-Ethnic Study of Atherosclerosis. BE measures included social destination density, walking destination density, proportion of land dedicated to retail, and network ratio (street connectivity). Global cognition was measured with the Cognitive Abilities Screening Instrument (CASI) and processing speed with the Digit Symbol Coding test (DSC). Multivariable random intercept logistic models tested associations between neighborhood BE at 2010-2012 and maintained/improved cognition (versus decline) from 2010-2018, and mediation by minutes of physical activity (PA)/week. The sample was an average of 67 years old (standard deviation = 8.2) (first cognitive measurement) and racially/ethnically diverse (29% African American, 11% Chinese, 17% Hispanic, 44% White). Compared to individuals with no walking destinations in the 1-mile surrounding their residence, those with 716 walking destinations (maximum observed) were 1.24 times more likely to have maintain/improved DSC score (Odds ratio: 1.24; 95% confidence interval: 1.03-1.45). No other associations were observed between BE and cognition, and PA minutes/week did not mediate the association between walking destination density and DSC change. This study provides limited evidence for an association between greater neighborhood walking destinations and maintained/improved processing speed in older age and no evidence for associations between the other BE characteristics and cognition. Future studies with finer grained BE and cognitive measures and longer-term follow up may be required.

Methods to Address Self-Selection and Reverse Causation in Studies of Neighborhood Environments and Brain Health

Preliminary evidence suggests that neighborhood environments, such as socioeconomic disadvantage, pedestrian and physical activity infrastructure, and availability of neighborhood destinations (e.g., parks), may be associated with late-life cognitive functioning and risk of Alzheimer’s disease and related disorders (ADRD). The supposition is that these neighborhood characteristics are associated with factors such as mental health, environmental exposures, health behaviors, and social determinants of health that in turn promote or diminish cognitive reserve and resilience in later life. However, observed associations may be biased by self-selection or reverse causation, such as when individuals with better cognition move to denser neighborhoods because they prefer many destinations within walking distance of home, or when individuals with deteriorating health choose residences offering health services in neighborhoods in rural or suburban areas (e.g., assisted living). Research on neighborhood environments and ADRD has typically focused on late-life brain health outcomes, which makes it difficult to disentangle true associations from associations that result from reverse causality. In this paper, we review study designs and methods to help reduce bias due to reverse causality and self-selection, while drawing attention to the unique aspects of these approaches when conducting research on neighborhoods and brain aging.

Neighborhood cognitive amenities? A mixed-methods study of intellectually-stimulating places and cognitive function among older Americans

Neighborhoods structure health and wellbeing in later life. Local spaces can encourage physically active and socially engaged aging in place, and may also nurture opportunities for cognitively-stimulating creative and complex activities such as reading; playing and listening to music; learning; and engagement in galleries, performing arts, and museums. These activities are associated with better cognitive health outcomes. In this exploratory sequential mixed-methods study, thematic analysis of interviews and ethnographic fieldwork with 125 diverse older adults in the Minneapolis (MN) metropolitan area (mean age 71 years) explored how and where older adults participated in intellectually-stimulating neighborhood activities. Thematic analysis indicated that libraries, higher education campuses, and sites of arts and culture were frequented intellectually-stimulating places, with racial differences in perception and usage. The qualitative findings informed quantitative investigation of associations between these amenities and cognitive function in a large national sample of aging Black and white Americans (n=21,165, mean age 67 years) in the Reasons for Geographic and Racial Differences in Stroke Study. We used multilevel linear regression models to examine whether living in a neighborhood with higher kernel densities of libraries, higher education campuses, and arts/cultural sites had a net positive effect on cognitive function. Analysis identified statistically significant positive associations between arts/cultural sites and cognitive function, with a significantly larger effect size for white versus Black participants. The study contributes new evidence to the emerging ecological model of cognitive health. It critically considers racial disparities in access to health-promoting neighborhood infrastructure and opportunities to age well in place.

Association of Racial Residential Segregation Throughout Young Adulthood and Cognitive Performance in Middle-aged Participants in the CARDIA Study

Importance

Neighborhood-level residential segregation is implicated as a determinant for poor health outcomes in black individuals, but it is unclear whether this association extends to cognitive aging, especially in midlife.

Objective

To examine the association between cumulative exposure to residential segregation during 25 years of young adulthood among black individuals and cognitive performance in midlife.

Design, Setting, and Participants

The ongoing prospective cohort Coronary Artery Risk Development in Young Adults (CARDIA) Study recruited 5115 black and white participants aged 18 to 30 years from 4 field centers at the University of Alabama, Birmingham; University of Minnesota, Minneapolis; Northwestern University, Chicago, Illinois; and Kaiser Permanente, Oakland, California. Data were acquired from February 1985 to May 2011. Among the surviving CARDIA cohort, 3671 (71.8%) attended examination year 25 of the study in 2010, when cognition was measured, and 3008 (81.9%) of those completed the cognitive assessments. To account for time-varying confounding and differential censoring, marginal structural models using inverse probability weighting were applied. Data were analyzed from April 16 to July 20, 2019.

Main Outcomes and Measures

Racial residential segregation was measured using the Getis-Ord Gi* statistic, and the mean cumulative exposure to segregation was calculated across 6 follow-up visits from baseline to year 25 of the study, then categorized into high, medium, and low segregation. Cognitive function was measured at year 25 of the study, using the Digit Symbol Substitution Test (DSST), Stroop color test (reverse coded), and Rey Auditory Verbal Learning Test. To facilitate comparison of estimates, z scores were calculated for all cognitive tests.

Results

A total of 1568 black participants with available cognition data were included in the analysis. At baseline, participants had a mean (SD) age of 25 (4) years and consisted of 936 women (59.7%). Greater cumulative exposure to segregated neighborhoods was associated with a worse DSST z score (for high segregation, β = -0.37 [95% CI, -0.61 to -0.13]; for medium segregation, β = -0.25 [95% CI, -0.51 to 0.0002]) relative to exposure to low segregation.

Conclusions and Relevance

In this cohort study, exposure to residential segregation throughout young adulthood was associated with worse processing speed among black participants as early as in midlife. This association may potentially explain black-white disparities in dementia risk at older age.

Associations Between Neighborhood Park Access and Longitudinal Change in Cognition in Older Adults: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Preliminary evidence suggests associations between neighborhood park access and better late-life cognition and reduced Alzheimer's disease (AD) risk.

OBJECTIVE

Examine associations between neighborhood park access and longitudinal change in cognition among U.S. older adults without dementia.

METHODS

We used 2000-2018 observational data from the population-based, multi-site Multi-Ethnic Study of Atherosclerosis (n = 1,733). Measures included proportion of neighborhood park space (park access), distance to nearest park, and 6-year dichotomous and continuous change in scores on the Cognitive Abilities Screening Instrument (CASI; global cognition) and Digit Symbol Coding task (processing speed). Multivariable random intercept models tested main associations and mediation by depressive symptoms, physical activity, and PM2.5 exposure. Effect modification by race (African Americans/Blacks versus Whites) was tested using interaction terms.

RESULTS

Greater park access (equivalent to 10%more in 1/2-mile around home) was associated with maintained/improved CASI score over six years independent of several covariates including individual- and neighborhood-level socioeconomic status (Odds ratio: 1.04; 95%confidence interval: 1.00-1.08). No other associations were observed with the dichotomous or continuous measures of cognitive change and no mediators were found. While a borderline association was seen between greater park access and maintained/improved CASI for African Americans/Blacks but not for Whites, effect modification was not confirmed by testing interaction terms.

CONCLUSION

Neighborhood park access may help maintain/improve late-life global cognition. However, our findings need replication in other population-based studies and regions. Additionally, studies are needed to determine if associations between park access and change in cognition vary by race/ethnicity to inform intervention efforts.

Weather Woes? Exploring Potential Links between Precipitation and Age-Related Cognitive Decline

Rain, snow, or ice may discourage older adults from leaving their homes with potential consequences for social isolation, decreased physical activity, and cognitive decline. This study is the first to examine potential links between annual precipitation exposure and cognitive function in a large population-based cohort of older Americans. We examined the association between precipitation (percent of days with snow or rain in the past year) and cognitive function in 25,320 individuals aged 45+ from the Reasons for Geographic and Racial Differences in Stroke Study. Linear mixed models assessed the relationship between precipitation and cognitive function, as well as rates of change in cognitive function with age. We found a non-linear relationship between precipitation and cognitive function. Compared to those exposed to infrequent precipitation (less than 20% of days with rain/snow in the past year), cognitive function was higher among older adults experiencing moderately frequent precipitation (20–40% of annual days with precipitation). However, beyond more than about 45% of days with precipitation in the past year, there was a negative association between precipitation and cognitive function, with faster rates of cognitive decline with age. These exploratory findings motivate further research to better understand the complex role of precipitation for late-life cognitive function.

The neighborhood effect of cognitive function on self-rated health: A population-based observational study

This study investigates the interaction between the neighborhood effect of cognitive function on self-rated health among middle aged and older adults. Data from the Korean Longitudinal Study on Aging (KLoSA) were analyzed. A total of 9,998 participants were selected for biennial follow-ups from 2006 to 2018 to estimate the probability of change in cognitive function according to individual, regional and dependent variables. A generalized estimating equation (GEE) model and chi-square test were used. The odds ratio (OR) of underestimation, when an individual's cognitive function is lower than his/her regional average of cognitive function, was 1.173 times higher (95 % Confidence Interval [CI]: 1.108-1.241, p-value: <.0001) compared to accurate, when an individual's cognitive function is equal to his/her regional average of cognitive function. The OR of individuals with low cognitive function in regions with low cognitive function levels had the highest probability of poor SRH (self-rated health) (OR: 3.525; 95 % CI: 3.182-3.905, p-value: <.0001) compared to individuals with high cognitive function in regions with high cognitive function levels. Findings speak of the importance of the neighborhood effect of cognitive function on self-rated health among Korean middle aged and older adults. Further research is needed to investigate the potential mediation of pleasurable mechanisms in the rapidly aging population of Korea.

Neighbourhood environment and dementia in older people from high-, middle- and low-income countries: results from two population-based cohort studies

BACKGROUND

A growing number of studies have explored how features of the neighbourhood environment can be related to cognitive health in later life. Yet few have focused on low- and middle-income countries and compared the results across different settings. The aim of this study is to investigate the cross-sectional associations between neighbourhood amenities and dementia in older people from high-, middle- and low-income countries.

METHODS

This study was based on two population-based cohort studies of people aged≥65: the Cognitive Function and Ageing Study II (CFAS II) in UK (N = 4955) and a subset of the 10/66 study in China, Dominican Republic and Mexico (N = 3386). In both cohorts, dementia was assessed using the Geriatric Mental State-Automated Geriatric Examination for Computer Assisted Taxonomy (GMS-AGECAT) algorithm. The 10/66 dementia diagnostic algorithm was also used as an additional criterion in the 10/66 study. Publicly accessible databases, Google Maps and Open Street Map, were used to obtain geographic information system data on distance to neighbourhood amenities, including lifestyle (cafés, libraries, movie theatres, parks), daily life (post offices, convenience stores), healthcare (hospitals, pharmacies) and percentages of local green and blue spaces within 400 and 800 m of participants' residences. Multilevel logistic regression was used to investigate the associations between these environmental features and dementia adjusting for sociodemographic factors and self-rated health.

RESULTS

Living far from daily life amenities was associated with higher odds of dementia in both CFAS II (1.47; 95% CI: 0.96, 2.24) and the 10/66 study (1.53; 95% CI: 1.15, 2.04), while living far from lifestyle (1.50; 95% CI: 1.13, 1.99) and healthcare amenities (1.32; 95% CI: 0.93, 1.87) was associated with higher odds of dementia only in the 10/66 study. A high availability of local green and blue spaces was not associated with dementia in either cohort yet living far from public parks was associated with lower odds of dementia in CFAS II (0.64; 95% CI: 0.41, 1.00).

CONCLUSIONS

The different relationships across cohorts may indicate a varying role for local amenities in diverse settings. Future research may investigate mechanisms related to these differences and social, cultural and historical influences on the interaction between neighbourhood amenities and older people.

Innovative solutions to enhance safe and green environments for ageing well using co-design through patient and public involvement

BACKGROUND

There is a need to develop innovative solutions to enhance safe and green physical environments, which optimise health, wellbeing and community participation among older adults. To develop solutions that meet the needs of a diverse ageing population, an interdisciplinary approach is needed. Our aim was to identify the needs of older people in relation to ageing well in the environment by bringing together knowledge from different perspectives using Patient and Public Involvement.

METHODS

An international consortium (Retrofit living For ageing well through Understanding and Redesign of Built environments consortium: ReFURB) was established in April 2018, including ten core members, to (i) explore cutting-edge solutions to safe living for ageing populations and (ii) develop innovative approaches to everyday physical environments, which bring about health benefits. We used a co-design, interdisciplinary framework involving older adults, carers, physiotherapists, geriatricians, engineers, human movement experts, geographers and psychologists from the UK and Australia. This engaged people in a 1 day workshop that comprised a series of presentations from international speakers on urban design, social connectedness, hazards and injury prevention, and the physical environment. Small group discussions (facilitated by consortium members) followed presentations to consider the opportunities, challenges and barriers encountered with ageing, which included the use of creative engagement activities (LEGO® Serious Play, mind maps, poster gallery walk), to help participants share personal stories and reflect on the issues raised. Thematic coding was used to synthesise the outputs of the small group work.

RESULTS

Five themes were identified across the workshops: access and transport; involvement of the whole community; restoration rather than redesign; assistive and digital technology; and intergenerational approaches. These dimensions related to the physical, social and nature-based qualities of everyday environments, as they pertain to ageing well.

CONCLUSIONS

Co-design was a valuable tool that helped understand the perceptions of participants and essential to develop effective interventions and solutions. Participants highlighted several issues affecting people as they age and key environmental considerations to promote wellbeing, activity, and participation. The consortium identified gaps in the existing evidence base and are now planning activities to further develop research ideas in collaboration with our co-design participants.

International Mind, Activities and Urban Places (iMAP) study: methods of a cohort study on environmental and lifestyle influences on brain and cognitive health

INTRODUCTION

Numerous studies have found associations between characteristics of urban environments and risk factors for dementia and cognitive decline, such as physical inactivity and obesity. However, the contribution of urban environments to brain and cognitive health has been seldom examined directly. This cohort study investigates the extent to which and how a wide range of characteristics of urban environments influence brain and cognitive health via lifestyle behaviours in mid-aged and older adults in three cities across three continents.

METHODS AND ANALYSIS

Participants aged 50-79 years and living in preselected areas stratified by walkability, air pollution and socioeconomic status are being recruited in Melbourne (Australia), Barcelona (Spain) and Hong Kong (China) (n=1800 total; 600 per site). Two assessments taken 24 months apart will capture changes in brain and cognitive health. Cognitive function is gauged with a battery of eight standardised tests. Brain health is assessed using MRI scans in a subset of participants. Information on participants' visited locations is collected via an interactive web-based mapping application and smartphone geolocation data. Environmental characteristics of visited locations, including the built and natural environments and their by-products (e.g., air pollution), are assessed using geographical information systems, online environmental audits and self-reports. Data on travel and lifestyle behaviours (e.g., physical and social activities) and participants' characteristics (e.g., sociodemographics) are collected using objective and/or self-report measures.

ETHICS AND DISSEMINATION

The study has been approved by the Human Research Ethics Committee of the Australian Catholic University, the Institutional Review Board of the University of Hong Kong and the Parc de Salut Mar Clinical Research Ethics Committee of the Government of Catalonia. Results will be communicated through standard scientific channels. Methods will be made freely available via a study-dedicated website.

TRIAL REGISTRATION NUMBER

ACTRN12619000817145.

Does community social capital buffer the relationship between educational disadvantage and cognitive impairment? A multilevel analysis in Japan

Background

This study explored the relationship between community social capital and cognitive impairment, with a focus on the buffering role of community social capital in the association between educational disadvantage and cognitive impairment in community-dwelling older adults in Japan.

Methods

We used data from two population-based, cross-sectional surveys targeting people aged ≥65 years in a suburban city of the Tokyo metropolitan area (n = 897; 49.8% men; average age = 74.4 years). Social capital included social support (emotional and instrumental support) and the strength of social networks (neighborly ties). To create district-level social capital indicators, we aggregated individual responses on social capital within each district. The Mini-Mental State Examination, Japanese version was used for the assessment of cognitive function.

Results

Using multilevel logistic regression analysis, we found that lower amounts of district-level emotional and instrumental support were associated with a greater likelihood of cognitive impairment among men. For women, district-level emotional support was associated with a greater likelihood of cognitive impairment. Additionally, a strong district-level social network buffered the relationship between low education and cognitive impairment in both sexes.

Conclusions

Community social capital appears to have a protective role in determining cognitive function in old age. Our findings may facilitate the development of new community-based strategies to combat dementia.

Associations between neighborhood built environment and cognition vary by apolipoprotein E genotype: Multi-Ethnic Study of Atherosclerosis

We examined whether neighborhood built environment (BE) and cognition associations in older adults vary by apolipoprotein E (APOE) genotype, a genetic risk factor for Alzheimer's disease (AD). We conducted a cross-sectional analysis of 4091 participants. Neighborhood characteristics included social and walking destination density (SDD, WDD), intersection density, and proportion of land dedicated to retail. Individuals were categorized as APOE ε2 (lower AD risk), APOE ε4 (higher AD risk), or APOE ε3 carriers. Among APOE ε2 carriers, greater proportion of land dedicated to retail was associated with better global cognition, and greater SDD, WDD, intersection density, and proportion of land dedicated to retail was associated with better processing speed. These associations were not observed in APOE ε3 or ε4 carriers. APOE ε2 carriers may be more susceptible to the potentially beneficial effects of denser neighborhood BEs on cognition; however, longitudinal studies are needed.

Cognitive Function of Elderly Persons in Japanese Neighborhoods: The Role of Street Layout

OBJECTIVES

The aims of this study were to examine (a) associations of two metric and space syntax measures of street layout with the cognitive function of Japanese older adults and (b) the extent to which objectively assessed physical activity mediated such associations.

METHODS

Cross-sectional data from 277 older adults who lived in Japan were used. Street layout attributes were objectively calculated for each participant's geocoded home location. The Mini-Mental State Examination was used to evaluate cognitive function. Physical activity was objectively assessed with accelerometers.

RESULTS

There was a statistically significant negative association between street integration and the odds of having cognitive impairment. Objectively assessed physical activity did not attenuate this relationship.

CONCLUSIONS

Our findings provide unique evidence regarding the importance of the topological aspects of street layouts in (re)designing neighborhoods to support mental illness.