People whose neighborhoods have been greened have lower levels of a blood marker of inflammation, which reduces the risk of cardiovascular disease.
- Higher levels of high-sensitivity C-reactive protein (hsCRP), a biomarker of inflammation, are linked to risk of cardiovascular disease, diabetes and certain cancers.
- One study found that residents of a green neighborhood had 13 to 20 percent lower levels of this blood marker of inflammation.
- This reduction in hsCRP levels leads to a decrease of almost 10 to 15% in the risk of heart attack, cancer or death from any disease.
Living in areas with low greenery is associated with a higher risk of diabetes, stroke and cardiovascular mortality, according to observational research. “However, it is unclear whether increasing greenness in neighborhoods directly leads to improvements in residents’ health.”
More than 8,000 trees planted in a neighborhood
To find out for sure, researchers from the University of Louisville (United States) conducted a study in which they recruited 745 people aged 25 to 75 from a neighborhood in south Louisville between 2018 and 2021. Participants provided information about their health status as well as blood, urine, hair and nail samples to measure their levels of inflammation. As a reminder, general inflammation is a strong risk indicator for heart disease and other chronic diseases, such as diabetes and cancers.
As part of the Green Heart project, scientists took detailed measurements of the vegetation cover in the neighborhood and the air pollution levels in the area. Then, they planted more than 8,000 large trees and shrubs in the designated neighborhood. After this intervention, the residents had to undergo medical examinations again. “We quantified high-sensitivity C-reactive protein (hsCRP), a biomarker of inflammation, in the samples.” The data was compared to that of residents of adjacent neighborhoods, where the team did not plant any trees.
Inflammation: 13-20% lower hsCRP levels in residents of a green neighborhood
According to the findings, presented at the 36th annual conference of the International Society for Environmental Epidemiology in Santiago, Chile, on August 26, adults living in the now-green area had 13 to 20 percent lower levels of high-sensitivity C-reactive protein than those living in areas that had no new trees or shrubs. A reduction in levels of this blood marker of inflammation corresponds to a nearly 10 to 15 percent drop in the risk of heart attack, cancer or death from any disease. “The trees that surround us are therefore beneficial for individual and collective health”, said the authors, who hope the study will strengthen the push to increase urban green spaces.
