Older racial/ethnic minority adults experience high incidence of Alzheimer’s disease and related dementias (AD/ADRD), age-related cognitive decline, stroke, and heart disease. “Our research has linked block-level greenness (e.g., tree canopy) to lower rates of chronic diseases, including Alzheimer’s disease, cardiometabolic indicators, such as diabetes, hypertension, and hyperlipidemia, heart disease and stroke,” said Dr. Brown.

Scott Brown, Ph.D.

Goals of the Grant

There are several objectives in this study. First, the study will determine if high level block-level greenness slows the age-related cognitive decline and risk for stroke and other vascular outcomes, over 10-14 years.  The study will also examine mechanisms that the research group believes might explain how greenness impacts brain and vascular health.  These mechanisms include physical activity, social support, depression, diabetes, hypertension, hyperlipidemia, inflammation, white matter hyperintensities in the brain and silent brain infarcts.  Additionally, the study will also study what kinds of individuals and in what kinds of social conditions may benefit the most from greenness to slow the deterioration of cognitive performance and vascular outcomes that occur with aging.

A very novel aspect of this study is that it will for the first time explore if greenness improves brain reserve.  That is, if it builds “neurobiological capital,” meaning that it protects the number of neurons and the connections between neurons.  Finally, the group will determine if greenness may protect against Alzheimer’s disease, and Alzheimer’s disease related dementias.

Jose Szapocznik, Ph.D.

The study on cognitive performance will use data collected over 10 years among 1,290 participants.  Magnetic resonance imaging will be used to evaluate brain health.  The study on vascular outcomes will involve all 3,298 NOMAS participants assessed over approximately 14 years.  The study will also determine how APOE, a gene that has been related to Alzheimer’s disease risk, interacts with greenness to influence brain and vascular health.

Impact on Public Health

Previous research on neighborhood greenness and health has demonstrated the health benefits that can be achieved even with small increases in greenness.  For instance, studies have shown that a greater presence of neighborhood greenness is associated with a lower prevalence of Alzheimer’s disease by 20%.  “Imagine if it were possible to establish that greening interventions (i.e., tree planting) could prevent Alzheimer’s disease and related dementias, as well as other brain and vascular health outcomes.   A relatively inexpensive intervention can dramatically reduce suffering in millions of persons and save billions of dollars in health care costs,” said Dr. Szapocznik.

Written by Veronica Bustabad

Published on November 23, 2021