Greenspace and Income Levels May Affect Brain and Health

A Miller School researcher found residents with less access to greenspace in lower-income neighborhoods may be more prone to white matter hyperintensities.

Lack of neighborhood greenspace and low income levels can increase risk for Alzheimer’s disease and related dementias, as well as stroke, 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.”

Miller School Researchers Analyze Greenspace Impact on Brain, Health

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 online October 25 in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.

Miller School co-authors included:

• Joyce Jimenez Zambrano, M.D., clinical research coordinator
• Simone Camacho, B.S., research associate
• 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

Dr. Besser mentee Devi Dhanekula, a student at Florida Atlantic University, also co-authored the study.

Less Greenspace, Brain Damage May Be More Likely

Prior studies have shown that white matter hyperintensities, a type of brain damage, are 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 imaging (MRI) of 1,260 cognitively normal individuals age 65 and older were taken approximately five years apart. The researchers then measured changes in white matter hyperintensities and brain ventricle size, and 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 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.”

Tags: Alzheimer's disease, brain health, dementia, Dr. Lilah M. Besser, neurology