The University of Louisville’s Green Heart Louisville Project has found that increasing the number of trees and shrubs in neighborhoods significantly reduces levels of inflammation, a key risk factor for heart disease and other chronic illnesses. The study showed that residents living in areas with more than double the previous tree and shrub count had lower levels of high-sensitivity C-reactive protein (hsCRP), a blood marker of inflammation, compared to those living outside the planted areas. Launched in 2018 by the Christina Lee Brown Envirome Institute, in collaboration with The Nature Conservancy, Washington University in St. Louis, and Hyphae Design Laboratory, the study aimed to assess the impact of increased greenery on heart health.
Researchers planted over 8,000 large trees and shrubs in designated neighborhoods of south Louisville and compared health data from 745 participants living in these “treated” areas with those in adjacent neighborhoods that did not receive new plantings. The results revealed a 13-20% reduction in hsCRP levels among residents in the greened areas, which corresponds to a nearly 10-15% reduction in the risk of heart attacks, cancer, or death from any disease. The findings show the power of environmental changes such as increasing green spaces to improve community health on a large scale.