New Study Finds Neighborhood Greenspaces and Income Levels Can Affect Brain and Health
October 25, 2023 — Lack of neighborhood greenspaces and low-income levels can increase risks for Alzheimer’s disease and related dementias, as well as strokes, according to a new study led by a University of Miami Miller School of Medicine researcher.
“Social determinants of health have a major impact on cognition, as well as cardiovascular and cerebrovascular health,” said Lilah M. Besser, Ph.D., M.S.P.H., research assistant professor of neurology at the Miller School’s Comprehensive Center for Brain Health in Boca Raton. “Understanding these interactions is crucial in developing interventions to improve brain health in individuals living in disadvantaged neighborhoods.”
Dr. Besser was the lead author of a collaborative study, “Neighborhood Greenspace and Neighborhood Income Associated with White Matter Grade Worsening: Cardiovascular Health Study,” published on online October 25 in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring. Miller School co-authors were Joyce Jimenez Zambrano, M.D., clinical research coordinator; Simone Camacho, B.S., research associate; and James Galvin, M.D., M.P.H., professor of neurology; chief, Division of Cognitive Neurology; director, Comprehensive Center for Brain Health; and director, Lewy Body Dementia Research Center of Excellence, as well as Dr. Besser’s mentee Devi Dhanekula, a student at Florida Atlantic University.
Prior studies have shown that white matter hyperintensities, a type of brain damage, have been linked to higher risks of Alzheimer’s disease and related dementias, as well as stroke, Dr. Besser said. Other studies have found an association between more greenspace, better cognition and less brain atrophy in later life, but an increased risk of dementia in lower socioeconomic neighborhoods.
In the new study, magnetic resonance images (MRI) of 1,260 cognitively normal individuals age 65 and up were taken approximately five years apart. The researchers then measured changes in white matter hyperintensities and brain ventricle size. They then used multivariable logistic regression to assess associations between a combined measure of neighborhood greenspace and neighborhood income and these MRI measures.
“We found that white matter worsening was more likely for individuals in lower greenspace-lower income neighborhoods than higher greenspace-higher income neighborhoods,” said Dr. Besser. “This combination may be a risk factor for brain health, but further research is needed.”
Dr. Besser noted that residential neighborhoods become increasingly important with age as individuals move into retirement, reduce their driving, and face new medical issues.
“Greenspaces can provide quiet moments for older adults to refresh their brains, reduce chronic stress, and increase physical activity,” she said. “It is one of the social determinants of health that can be modified by policy interventions, such as creating more parks and planting more trees.”
