Adding Trees to Neighborhoods Reduces Residents' Inflammation
Plant some trees if you want to reduce your inflammation.
Researchers at the University of Louisville found by planting trees in previously barren areas of neighborhoods they were able to lower the markers of inflammation found in the blood of residents.
by Staff Reports
Studies have shown people who spend time in nature have less stress, but the effect of green spaces is not limited to just mental health. Researchers at the University of Louisville found by planting trees in previously barren areas of neighborhoods they were able to lower the markers of inflammation found in the blood of residents.
General inflammation in the body is an important indicator for the risk of chronic diseases such as heart disease and others. UofL's Green Heart Louisville Project planted more than 8,000 large trees and shrubs in a certain neighborhood in south Louisville, more than doubling what had been there before. And the result was up to a 20 percent decrease in a biomarker of inflammation.
Louisville's Envirome Institute along with The Nature Conservancy and others combined in 2018 to begin the study to see if living among more densely greened spaces can contribute to better health. The study was structured to mirror clinical trials that measure the effectiveness of medical treatments.
The control group was comprised of the people living in the nearby neighborhood where additional trees were not planted and the trial group included the residents of the areas where new trees and shrubs were added. The health of both groups was tracked before and after the landscape work was completed.
The study was isolated to a four-square-mile are of south Louisville and researchers took blood, urine, hair and nail samples from the 745 people living in the area. Researches also measured the air pollution and took took detailed measurements of the tree coverage.
Residents in the area where the trees were added had 13-20 percent lower levels of high-sensitivity C-reactive protein (hsCRP), which is a biomarker of general inflammation, than those in the areas where trees were not added.
"These results from the Green Heart Louisville Project indicate that trees contribute more to our lives than beauty and shade. They can improve the health of the people living around them," said Aruni Bhatnagar, director of the Envirome Institute and UofL professor of medicine. "Although several previous studies have found an association between living in areas of high surrounding greenness and health, this is the first study to show that a deliberate increase in greenness in the neighborhood can improve health. With these results and additional studies that we hope to report soon, we are closer to understanding the impact of local tree cover on residents' health. This finding will bolster the push to increase urban greenspaces."
Researchers say a reduction of that magnitude in hsCRP equates to as much as a 15 percent reduction in the risk of heart attacks, cancer of dying from any disease.
"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."