Large trees planted in Wyandotte Park as part of the Christina Lee Brown Envirome Institute's Green Heart Louisville Project.

Green Heart Louisville Project

This groundbreaking project is a clinical trial where trees are the medicine.

What is the Green Heart Louisville Project?

With a multimillion-dollar investment in underserved neighborhoods in South Louisville, the Green Heart Project seeks to demonstrate the scientific link between nature and human health.  

By tackling two critical problems – air pollution and chronic disease – with a new, nature-based approach, Green Heart hopes to create a platform for major change. What we learn in Louisville could improve the lives of thousands of people here in our city and potentially millions of people worldwide. 

Project Goals

While there is a growing body of scientific observations linking environmental health to the wellbeing of people, especially in urban areas, the Green Heart Louisville Project is examining, for the first time, if increasing greenness in an urban community reduces the levels of air pollution in the neighborhood, decreases the risk of chronic disease and increases outdoor activity and relationships between neighbors.

Green Heart Will Help Us Discover

  • How to plant trees in urban communities to maximize the removal of air pollution
  • If increasing green space affects the risks of developing obesity, diabetes and heart disease
  • If increasing urban green space reduces mental stress, enhances social cohesion and increases physical activity
  • If urban green space affects crime rates, property values, storm water runoff, energy use and heat island effect. 

First Clinical Outcomes

In August of 2024, the Green Heart Louisville team announced the first clinical outcomes from the study. Initial findings indicate that people living in neighborhoods where the number of trees and shrubs was more than doubled showed lower levels of a blood marker of inflammation than those living in the control area. General inflammation is an important risk indicator for heart disease and other chronic diseases.

Those living in the greened area had 13-20% lower levels of a biomarker of general inflammation, a measure called high-sensitivity C-reactive protein (hsCRP), compared to those living in the areas that did not receive any new trees or shrubs. Higher levels of hsCRP are strongly associated with a risk of cardiovascular disease and are an even stronger indicator of heart attack risk than cholesterol levels. Higher CRP levels also indicate a higher risk of diabetes and certain cancers.

Tree Planting & Maintenance

Large-scale tree and shrub planting was completed in June 2022, with thousands of new plants and trees placed across the study area. Green Heart Project trees are strategically placed to reduce air pollution in areas surrounding homes, businesses and roadways, including the Watterson Expressway (I-264), which cuts through the center of the study area.

FY25 Project Snapshot

30

Community meetings

15

Peer-reviewed research papers

1K+

Enrolled health study participants

The Green Heart Project Receives National Acclaim

The Green Heart Louisville Project continues to receive national attention. PBS NewsHour heralded the project’s launch in 2019. The project was presented at multiple international conferences including the International Urban Forestry Conference in Washington DC in 2023 as well as at the annual conference of Keep America Beautiful in San Diego in February 2024. The project received extraordinary coverage in The Washington Post (login required) in early 2024 as one of the most remarkable health/science projects in the country. The announcement of the first clinical results was covered by many news outlets including the TODAY Show

See media coverage highlights

Visit the Green Heart Project Website

Learn more about the Green Heart Louisville Project and see how you can participate.