Neighborhood Green Land Cover and Neighborhood-Based Walking in U.S. Older Adults

Environmental determinants of health: Measuring multiple physical environmental exposures at the United States census tract level

Physical environment plays a key role in determining human health risks. Exposure to toxins, weather extremes, degraded air and water quality, high levels of noise and limited accessibility to green areas can negatively affect health. Furthermore, adverse environmental exposures are often correlated with each other and with socioeconomic status, thereby compounding disadvantages in marginalized populations. Moreover, despite their importance in determining human health risks, the role of multiple environmental exposures is not well studied, and only a few resources contain aggregate environmental exposure data and only for selected areas of the contiguous US. To fill these gaps, we took a cumulative approach to measuring the environment by generating a composite Multi-Exposure Environmental Index (MEEI) as a US Census Tract-level summary of key environmental factors with known health effects. This measure quantifies multiple environmental exposures in the same area that can result in additive and synergistic effects on health outcomes. This information is crucial to better understand and possibly leverage environmental determinants of health for informed policy-making and intervention.

Longitudinal study of changes in greenness exposure, physical activity and sedentary behavior in the ORISCAV-LUX cohort study

BACKGROUND

Greenness exposure has been associated with many health benefits, for example through the pathway of providing opportunities for physical activity (PA). Beside the limited body of longitudinal research, most studies overlook to what extent different types of greenness exposures may be associated with varying levels of PA and sedentary behavior (SB). In this study, we investigated associations of greenness characterized by density, diversity and vegetation type with self-reported PA and SB over a 9-year period, using data from the ORISCAV-LUX study (2007-2017, n = 628).

METHODS

The International Physical Activity Questionnaire (IPAQ) short form was used to collect PA and SB outcomes. PA was expressed as MET-minutes/week and log-transformed, and SB was expressed as sitting time in minutes/day. Geographic Information Systems (ArcGIS Pro, ArcMap) were used to collect the following exposure variables: Tree Cover Density (TCD), Soil-adjusted Vegetation Index (SAVI), and Green Land Use Mix (GLUM). The exposure variables were derived from publicly available sources using remote sensing and cartographic resources. Greenness exposure was calculated within 1000m street network buffers around participants' exact residential address.

RESULTS

Using Random Effects Within-Between (REWB) models, we found evidence of negative within-individual associations of TCD with PA (β = - 2.60, 95% CI - 4.75; - 0.44), and negative between-individual associations of GLUM and PA (β = - 2.02, 95% CI - 3.73; - 0.32). There was no evidence for significant associations between greenness exposure and SB. Significant interaction effects by sex were present for the associations between TCD and both PA and SB. Neighborhood socioeconomic status (NSES) did not modify the effect of greenness exposure on PA and SB in the 1000 m buffer.

DISCUSSION

Our results showed that the relationship between greenness exposure and PA depended on the type of greenness measure used, which stresses the need for the use of more diverse and complementary greenness measures in future research. Tree vegetation and greenness diversity, and changes therein, appeared to relate to PA, with distinct effects among men and women. Replication studies are needed to confirm the relevance of using different greenness measures to understand its' different associations with PA and SB.

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 Socioeconomic Status, Green Space, and Walkability and Risk for Falls Among Postmenopausal Women: The Women's Health Initiative

PURPOSE

This study estimated associations between neighborhood socioeconomic status (NSES), walkability, green space, and incident falls among postmenopausal women and evaluated modifiers of these associations, including study arm, race and ethnicity, baseline household income, baseline walking, age at enrollment, baseline low physical functioning, baseline fall history, climate region, and urban-rural residence.

METHODS

The Women's Health Initiative recruited a national sample of postmenopausal women (50-79 years) across 40 U.S. clinical centers and conducted yearly assessments from 1993 to 2005 (n = 161,808). Women reporting a history of hip fracture or walking limitations were excluded, yielding a final sample of 157,583 participants. Falling was reported annually. NSES (income/wealth, education, occupation), walkability (population density, diversity of land cover, nearby high-traffic roadways), and green space (exposure to vegetation) were calculated annually and categorized into tertiles (low, intermediate, high). Generalized estimating equations assessed longitudinal relationships.

RESULTS

NSES was associated with falling before adjustment (high vs. low, odds ratio, 1.01; 95% confidence interval, 1.00-1.01). Walkability was significantly associated with falls after adjustment (high vs. low, odds ratio, 0.99; 95% confidence interval, 0.98-0.99). Green space was not associated with falling before or after adjustment. Study arm, race and ethnicity, household income, age, low physical functioning, fall history, and climate region modified the relationship between NSES and falling. Race and ethnicity, age, fall history, and climate region modified relationships between walkability and green space and falling.

CONCLUSIONS

Our results did not show strong associations of NSES, walkability, or green space with falling. Future research should incorporate granular environmental measures that may directly relate to physical activity and outdoor engagement.

Diversity of Studies on Neighborhood Greenspace and Brain Health by Racialized/Ethnic Group and Geographic Region: A Rapid Review

Studies examining associations between greenspace and Alzheimer's disease and related dementia (ADRD) outcomes are rapidly on the rise, yet no known literature reviews have summarized the racialized/ethnic group and geographic variation of those published studies. This is a significant gap given the known disparities in both greenspace access and ADRD risk between racialized/ethnic groups and between developed versus developing countries. In this rapid literature review, we (1) describe the diversity of published greenspace-brain health studies with respect to racialized/ethnic groups and geographic regions; (2) determine the extent to which published studies have investigated racialized/ethnic group differences in associations; and (3) review methodological issues surrounding studies of racialized/ethnic group disparities in greenspace and brain health associations. Of the 57 papers meeting our inclusion criteria as of 4 March 2022, 21% (n = 12) explicitly identified and included individuals who were Black, Hispanic/Latinx, and/or Asian. Twenty-one percent of studies (n = 12) were conducted in developing countries (e.g., China, Dominican Republic, Mexico), and 7% (n = 4) examined racialized/ethnic group differences in greenspace-brain health associations. None of the studies were framed by health disparities, social/structural determinants of health, or related frameworks, despite the known differences in both greenspace availability/quality and dementia risk by racialized/ethnic group and geography. Studies are needed in developing countries and that directly investigate racialized/ethnic group disparities in greenspace-brain health associations to target and promote health equity.

Neighborhood greenspace and cognition: The cardiovascular health study

OBJECTIVES

We examined whether greenspace measures (overall percent greenspace and forest, and number of greenspace types) were associated with clinically adjudicated dementia status.

METHODS

In a sample of non-demented older adults (n = 2141, average age = 75.3 years) from the Cardiovascular Health and Cognition Study, Cox proportional hazard and logistic regression analyses were used to estimate associations of baseline greenspace with risks of incident dementia and MCI, respectively, while adjusting for demographics, co-morbidities, and other neighborhood factors. We derived quartiles of percent greenness (greenspace), forest (percent tree canopy cover), and tertiles of greenspace diversity (number of greenspace types) for 5-km radial buffers around participant's residences at study entry (1989-1990) from the 1992 National Land Cover Dataset. Dementia status and mild cognitive impairment (MCI) over 10 years was clinically adjudicated.

RESULTS

We observed no significant association between overall percent greenspace and risk of mild cognitive impairment or dementia and mostly null results for forest and greenspace diversity. Forest greenspace was associated with lower odds of MCI (OR quartile 4 versus 1: 0.54, 95% CI: 0.29-0.98) and greenspace diversity was associated with lower hazard of incident dementia (HR tertile 2 versus 1: 0.70, 95% CI = 0.50-0.99).

DISCUSSION

We found divergent results for different types of greenspace and mild cognitive impairment or dementia. Improved greenspace type and diversity measurement could better characterize the association between greenspace and cognition.

Redlining and Neighborhood Walking in Older Adults: The 2017 National Household Travel Survey

INTRODUCTION

In the 1930s, Black, working-class, and immigrant neighborhoods were color coded on maps (i.e., redlining) indicating investment risk, which negatively impacted mortgage attainment/homeownership for these groups and led to long-standing segregation by race/ethnicity and socioeconomic status. Limited studies have investigated the health impacts of redlining, particularly among older adults who tend to stay closer to their residences. This study examines whether older adults in historically redlined neighborhoods report less neighborhood walking and whether associations vary by race/ethnicity and income.

METHODS

The sample included 4,651 individuals aged ≥65 years from the 2017 U.S. National Household Travel Survey. U.S. Census tract‒based redlining scores were 1=best, 2=still desirable, 3=definitely declining, and 4=hazardous. Multivariable negative binomial regression tested the associations between redlining and neighborhood walking/day in the overall sample and with stratification by poverty status (analyzed in 2022).

RESULTS

Participants were on average aged 73 years, and 11% were African/American Black, 75% were White, 8% were Hispanic/Latinx, and 6% were of other race/ethnicity. Participants reported a mean of 7.1 neighborhood walking minutes/day (SD=20.6), and 60% lived in definitely declining or hazardous neighborhoods. Individuals in hazardous neighborhoods (versus those in best neighborhoods) reported less neighborhood walking (prevalence ratio=0.64; 95% CI=0.43, 0.97). Among those living in poverty, living in definitely declining and hazardous neighborhoods was associated with less neighborhood walking (prevalence ratio=0.39 [95% CI=0.20, 0.79] and 0.39 [95% CI=0.18, 0.82], respectively).

CONCLUSIONS

Less neighborhood walking was reported among individuals living in neighborhoods with a historic redlining score of definitely declining or hazardous. Future studies using larger, more diverse cohorts may elucidate whether associations differ by race/ethnicity and geographic location/city.

Evaluating Racial/Ethnic Equity in Planning-Related U.S. Health Impact Assessments Involving Parks and Greenspaces: A Review

Problem research strategy and findings

Health impact assessment (HIA) reports are used by government agencies, other organizations, and stakeholders to evaluate potential health effects of plans/policies/projects. HIAs have the potential to promote anti-racist practices. We developed and used the Tool for the Racial/Ethnic Equity Evaluation of Health Impact Assessments (TREE-HIA) to score 50 U.S. HIA reports on planning-related projects/plans involving parks and greenspaces (2005-2020). More recent and more comprehensive HIA reports addressed racial/ethnic equity to a greater degree (e.g., median TREE-HIA scores: -1.3 in 2009-2012, 4.0 in 2017-2020, where higher scores indicate greater racial/equity considerations). Overall, HIA reports addressed racial/ethnic equity to a lesser degree than expected given the principal tenet of equity guiding HIAs and urban planning alike (42% had negative TREE-HIA scores indicating inadequate racial/ethnic equity consideration). However, the limited number and types of HIAs included in this study may affect generalization to all HIAs.

Takeaway for practice

HIAs incorporating racial/ethnic equity comprehensively throughout the HIA process will better enable urban planners, HIA practitioners, decision makers, and communities of color to work together to combat racist planning practices through the shared goals of addressing health disparities and equity. TREE-HIA provides professionals and researchers with a brief tool that can be used/adapted to guide and evaluate future HIAs for racial/ethnic equity considerations.

Outdoor green space exposure and brain health measures related to Alzheimer's disease: a rapid review

OBJECTIVES

Summarise studies of outdoor green space exposure and brain health measures related to Alzheimer's disease and related disorders (ADRD), and determine scientific gaps for future research.

DESIGN

Rapid review of primary research studies.

METHODS AND OUTCOMES

PubMed, Embase and Web of Science Core Collection were searched for articles meeting the criteria published on/before 13 February 2020. The review excluded papers not in English, focused on transient states (eg, mental fatigue) or not using individual-level measures of brain health (eg, average school test scores). Brain health measures of interest included cognitive function, clinical diagnosis of cognitive impairment/dementia/ADRD and brain biomarkers such as those from MRI, measures typically associated with ADRD risk and disease progression.

RESULTS

Twenty-two papers were published from 2012 to 2020, 36% on <18 years old, 32% on 18-64 years old and 59% on ≥65 years old. Sixty-four per cent defined green space based on the Normalised Difference Vegetation Index ('greenness'/healthy vegetation) and 68% focused on cognitive measures of brain health (eg, memory). Seventeen studies (77%) found green space-brain health associations (14 positive, 4 inverse). Greater greenness/green space was positively associated various cognitive domains in 10 studies and with MRI outcomes (regional brain volumes, cortical thickness, amygdala integrity) in three studies. Greater neighbourhood greenness was associated with lower odds/risk of cognitive impairment/ADRD in some studies but increased odds/risk in others (n=4 studies).

CONCLUSIONS

Published studies suggest positive green space-brain health associations across the life course, but the methods and cohorts were limited and heterogeneous. Future research using racially/ethnically and geographically diverse cohorts, life course methods and more specific green space and brain health measures (eg, time spent in green spaces, ADRD biomarkers) will strengthen evidence for causal associations.