Green space and cognitive health: the role of community design in environmental health

Johns Hopkins University, Baltimore MD

Investigators

Abstract

In 2020, an estimated 5.8 million Americans had Alzheimer’s disease (AD), the most common cause of dementia, and this number is expected to reach 13.8 million by 2050. Alzheimer’s Disease and related dementias (ADRD) take an enormous toll on individuals affected, as well as their caregivers. Because disease- modifying therapies have proved largely ineffective, a priority is placed on finding ways to prevent this debilitating disease. Since neighborhood design factors can be modified at the population level, they are an attractive area for intervention. Green space is one neighborhood design element that may be associated with cognitive function because exposure to it may reduce stress, improve mood, promote physical activity, and provide opportunities for social engagement, all of which have been associated with better cognitive health. Some populations are more likely to live in neighborhoods with lower green space than others and design and planning policies have been implicated in the distribution of green space. Recent efforts have increased the amount and quality of green space through park improvement projects, street tree plantings, and vacant lot restoration. However, it is unclear if green space improvements are harmful or beneficial to residents, particularly in neighborhoods that are undergoing change. In the proposed work, we will (1) assess the cross-sectional and longitudinal association between changes in green space and cognitive function, cognitive decline, and dementia over a 20-year period; (2) estimate the association between community planning policies and cognitive function, cognitive decline, and dementia; and determine if this association is mediated by green space exposure; (3) determine if (a) the association between green space and cognitive function, cognitive decline, and dementia is moderated by neighborhood change; and (b) there is an independent association between neighborhood change and psychosocial stressors, mental health, and perceived neighborhood characteristics; and (4) partner with a national network of local non-profit organizations to explore obstacles and facilitators to green space improvements. This work has the potential to provide guidance to improve cognitive health for all Americans.