August 30, 2024
Thom Carroll/for PhillyVoice
People who live in areas with more trees and shrubs have lower levels of a form of inflammation linked to an increased risk of heart disease, diabetes and several cancers, study shows. Above, a file photo taken on Parrish Street in Fairmount.
Research suggests living in a neighborhood filled with trees can have positive health benefits, raising the possibility that greener urban areas may help improve public health.
The latest study, conducted by researchers at the University of Louisville, found that people who lived in areas with double the number of trees and shrubs had lower levels of a biomarker of general inflammation compared to those who lived in areas without trees. That biomarker is tied to an increased risk of heart disease, heart attacks, diabetes and some cancers.
Researchers collected data from 745 people living within a four-square-mile area of South Louisville, Kentucky, sampling their blood, urine, nails and hair before and after they planted more than 8,000 trees and shrubs within a portion of the study area. They found that the people who live near more tree coverage had 13% to 20% lower levels of the inflammation biomarker. The disparity was comparable to the difference between people who exercise regularly and those who don't.
"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," said researcher Aruni Bhatnagar, a professor of medicine at Louisville.
"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."
A 2018 study from the University of Pennsylvania found that greening vacant city lots can help reduce stress and depression. Similar studies show that living near trees boosts overall mental health and may even help increase life expectancy.
In Philadelphia, groups like the Pennsylvania Horticultural Society are attempting to expand the city's tree canopy by 20-30% over the next decade. By 2035, the city wants to have 30% tree coverage in each neighborhood. The push to plant more trees was spurred by a 2019 report that found the city's tree canopy was shrinking.
Philadelphia Parks & Recreation gives out more than 1,000 trees each spring and fall through the TreePhilly program it runs with the Fairmount Park Conservancy.
The trees are given out trees that residents can plant in their yards at community events hosted in April and May, and again in October and November. People with limited mobility can fill out applications to have trees delivered to their homes and planted by arborists.
Residents and businesses also can request trees be planted by Parks & Recreation along their sidewalks. Alternatively, property owners can contract a certified arborist to plant a tree along their sidewalks at their own expense.
