Planting trees can have immediate health benefits

New research has found that a concerted tree and shrub planting campaign can have a positive impact on the health of those living in the area, extremely quickly.

Through their innovative Green Heart Louisville Project, a team from The University of Louisville found that people living in neighborhoods where a planting programme had doubled the number of trees and shrubs had lower levels of high-sensitivity C-reactive protein (hsCRP) in their blood.

UofL representatives plant a tree following yesterday’s announcement of their research results

Higher levels of hsCRP are associated with a risk of cardiovascular disease and are an even stronger indicator of heart attack than cholesterol levels. Higher CRP levels also indicate a higher risk of diabetes and certain cancers.

The Green Heart Project, has 745 participants aged between 25-75, living in a low-to-middle income neighborhood.

The researchers identified 16 demographically and environmentally similar clusters within that neighbourhood and divided them into target and control areas.

In 2018 and 2021, participants living within each area were enrolled and their health information collected.

Between 2019 and 2022, the Green Heart Project planted 8,425 evergreen trees and shrubs of 42 different species from five different families and 630 deciduous trees. Evergreens were pine, cypress, yew, holly and magnolia. Deciduous trees were mainly dogwood, oak and serviceberry.

Over the next two years, participants in both areas were given repeated health examinations.

It was found that those living in the greened area had 13-20% lower levels of  hsCRP than those living in the areas that did not receive any greening. A reduction of hsCRP by this percentage equates to a 10-15% reduction in the risk of heart attacks, cancer or dying from any disease.

Aruni Bhatnagar, director of the Envirome Institute and UofL professor of medicine said: ‘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.

‘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.’

Pic: UofL