LOUISVILLE – A years-long research project by the University of Louisville, The Nature Conservancy and other partners has found that planting thousands of trees and shrubs in a south Louisville neighborhood has improved the health of hundreds of residents.
The University of Louisville Christina Lee Brown Envirome Institute launched the Green Heart Louisville Project in 2018. Over 8,000 large trees and shrubs were planted over an area of six kilometers and the health of 745 residents was examined before and after the trees were planted.
The researchers took blood, urine, hair and nail samples to collect health data from residents, while also measuring tree cover and levels of air pollution in the area. The researchers then compared the data they collected with that of urban residents outside the study area.
The results, announced Tuesday before a crowd of supporters at Wyandotte Park in south Louisville, showed that residents of the greener area had 13 to 20 percent lower biomarker levels for general inflammation.
The trees along a walkway in Wyandotte Park are among thousands planted in residential areas and along the nearby highway corridor. “You all see the beautiful trees behind me? Well, they are more than just beautiful. They are medicine,” said Kim Schatzel, president of the University of Louisville, to the crowd of supporters. “You are part of the revolutionary project to document and understand how trees affect the health of the people around them.”
The biomarkers measured are called high-sensitivity C-reactive proteins, and higher levels of these proteins are closely linked to cardiovascular disease. According to a study by the University of Louisville releaseare “an even stronger predictor of heart attacks than cholesterol levels.” Higher levels of these proteins are also associated with an increased risk of diabetes and some cancers.
Aruni Bhatnagar, director of the Christiana Lee Brown Environmental Institute, called the research potentially promising for reducing heart attacks among Louisivill residents.
“We have over 1,800 to 2,000 heart attacks in Louisville every year, and if we can reduce the number of heart attacks by 10%, that’s 200 fewer,” Bhatnagar said. “If we can work for the entire city on the scale we’ve done here, that will have a tremendous benefit. We can only imagine what that would mean for the entire country.”
Bhatnagar said that while previous studies have shown that people living in “green communities” have lower mortality rates, he was not aware of any studies like the University of Louisville project that compared the health effects of green spaces in a community.
Toni Smith, 71, is one of the study participants and has lived across the highway from Wyandotte Park for 17 years. She said the additional trees have helped beautify her neighborhood while blocking some of the air pollution and noise from the highway.
Smith, sitting in the shade of a tree in the park, said the tree cover has a “certain calming effect,” especially for people who love nature. She said she is a big proponent of anything that can help improve the environment and health of her neighborhood, and mentioned that the study also served as a helpful health screening for participants.
She asked the researchers to plant a tree in her own garden, but there was no space.
“Because of my love of nature, I didn’t have a single square inch of space to plant a tree, otherwise they definitely would have come,” Smith said.
