For all you city-dwellers out there, next time you walk by a vacant lot that’s been refurbished with green gardens and budding trees, take note of your heart rate. You might find the pleasantly green view caused a welcome moment of relaxation and lowered stress.
At least that’s what researchers found in a new study published this week in the American Journal of Public Health. In monitoring the ambulatory heart of rate of study participants in Philadelphia before and after they walked by vacant urban lots that had received a “greening remediation treatment,” researchers found that seeing a greened lot decreased people’s heart rate significantly more than seeing a regular vacant lot.
To conduct the study, researchers used a heart rate monitor with GPS to measure participants’ stress response as they went on a planned walk through their respective neighborhoods. Vacant lots in one neighborhood had received a greening treatment, which included planting grass and trees, removing garbage and installing a low fence, while another neighborhood’s vacant lots received no greening treatment. Participants walked through their neighborhoods before the greening intervention and three months after the intervention. Study authors Eugenia South, Michelle Kondo, Rose Cheney and Charles Branas write:
The body’s stress response is a reasonable biological pathway for understanding the impact of neighborhood blight on health. Although this response is protective in acute situations, permanent downstream inflammatory changes and dysregulation of cardiovascular, neurological, and endocrine systems accumulate over a lifetime for persons repeatedly exposed to stressors in their neighborhood surroundings. Basic structural improvements to blighted neighborhood environments, such as “greening” vacant lots, offers a promising and sustainable, yet underused, solution to such stressors.
Among the study participants, average heart rate went from 103.3 beats per minute before the greening intervention to 107.2 beats per minute after the greening intervention, for a total increase of 3.9 beats per minute. When participants weren’t in view of any lots, average heart rate went from 101.2 to 107.2, for a total increase of 6 beats per minute. When in view of nongreened vacant lots, average heart rates went from 99.6 in the preintervention period to 109.1 three months later, for an increase of 9.5 beats per minute. So, what do all those beats mean? According to the researchers’ calculations, the average reduction in heart rate associated with being near the greened lots was more than five beats per minute lower than when near vacant lots that hadn’t been greened.
In comparison, there was minimal change in heart rates among study participants who walked by nongreened vacant lots during both the preintervention and postintervention time periods. All the study participants actually lived in the neighborhoods where the walking study was conducted, so changes in heart rates wouldn’t be attributable to being in unfamiliar surroundings. The study is the first neighborhood walking trial in which physiological effects were measured in real time among people reacting to sites in their own neighborhoods.
The authors noted that their study adds to the growing body of research that finds structural changes in urban environments can have positive impacts on human health. As many public health practitioners say when it comes to health: place matters.
“Vacant lot greening requires no individual action to be effective and is a relatively simple and inexpensive intervention with the potential to affect the health of many residents,” the study stated. “If neighborhood blight contributes to the development of stress in a neighborhood, improvements to these physical conditions may lead to widespread downstream health benefits.”
Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.