The Green Heart Project in Louisville, Kentucky, is a pioneering study that links urban greening to human health. Launched in 2018, it’s a controlled, community-based trial in a racially diverse, working- to middle-class area of south Louisville with about 30,000 residents. The goal is to see whether planting trees and shrubs can lower disease risk, reduce pollution, and improve social and mental well-being.

Early results released in 2024 show promising outcomes: neighborhoods that received the greening saw 13–20% lower levels of general inflammation in residents compared to control areas. This drop translates to a 10–15% lower risk of heart attacks and other chronic diseases. The new trees also help clean the air and reduce noise, adding both health and environmental benefits.

“'Most of us intuitively understand that nature is good for our health. But scientific research testing, verifying, and evaluating this connection is rare,' said Katharine Hayhoe, chief scientist of The Nature Conservancy. 'These recent findings from the Green Heart Project build the scientific case for the powerful connections between the health of our planet and the health of all of us.'”

ARTICLE: The Green Heart Louisville Project

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