Blue spaces and incident dementia: Differences by geospatial and historical contexts

Area of Science:

• Environmental Health
• Neuroscience
• Urban Planning

Background:

• Blue spaces (water bodies) may influence cognitive health, with effects potentially varying by usage and spatial context.
• Previous research suggests a link between natural environments and well-being, but specific associations with dementia risk require further investigation.
• The industrial history of urban areas like Pittsburgh may modify the relationship between blue spaces and health outcomes.

Purpose of the Study:

• To investigate the association between blue space exposure and the risk of developing dementia.
• To examine how different spatial scales (1 km buffers and U.S. Census tracts) influence these associations.
• To specifically analyze these relationships within Pittsburgh, considering its unique industrial past.

Main Methods:

• Utilized data from the Cardiovascular Health Cognition Study, including 2924 adults aged 65+ (651 from Pittsburgh).
• Dementia cases were clinically adjudicated between 1992 and 1999.
• Blue space density was quantified using 1 km radial buffers and U.S. Census tracts.

Main Results:

• In Pittsburgh, higher blue space density at the buffer level was associated with an increased risk of mixed/vascular dementia (HR=2.87), but not Alzheimer's disease.
• This association was slightly attenuated after adjusting for individual and neighborhood confounders (HR=2.65).
• Tract-level associations showed similar trends but were less pronounced after adjustments.

Conclusions:

• Blue space proximity, particularly at a localized buffer level, is associated with vascular dementia risk, even after accounting for social and environmental factors.
• The findings underscore the need to consider the scale of spatial units and the historical context of blue spaces in dementia research.
• Future studies should differentiate blue spaces based on their past uses to better understand their impact on cognitive health.