Trees don’t benefit health for everyone

A study published in Lancet Regional Health–Americas indicates that the biological health benefits of nature are not experienced equally across all populations, challenging the assumption that increasing urban greenery automatically improves health for everyone.

While being around trees is known to enhance health by increasing longevity and lowering stress, research led by Amber Pearson, a professor in the public health department in the Michigan State University College of Human Medicine, found that these benefits are not universally shared.

The research team examined the relationship between residential tree canopy and allostatic load, which is defined as the cumulative wear and tear on the body caused by chronic stress.

To conduct the analysis, Pearson’s team used data from the Centers for Disease Control and Prevention involving 40,307 adults. This information was matched with satellite maps of tree cover to analyze data for every census block in the country.

The findings revealed that while a higher tree canopy is generally associated with a lower allostatic load, this positive correlation did not extend to the most vulnerable groups.

Specifically, the association between trees and better health was present for individuals who were employed and had higher levels of education and income. However, the researchers found no such association for less-advantaged people.

The study further noted that these findings were consistent for Hispanic and non-Hispanic white subpopulations, but not for non-Hispanic Black participants.

Data showed that 24% of non-Hispanic Black participants lived in neighborhoods with a high tree canopy. Despite this access to greenery, they did not show the same reduction in allostatic load seen in white and Hispanic groups.

Pearson suggests that for certain minority groups, the calming effects of nature may be overridden by other social or environmental stressors, such as discrimination.

There are other things that may be more stressful in disadvantaged groups like unfair treatment, lack of good job opportunities, or poor neighborhood conditions that tree canopy is not going to overcome,

Amber Pearson

The study concludes that while urban greening remains a vital tool for public health, it cannot function as a standalone solution for the most vulnerable populations.

To ensure that the health benefits of nature are accessible to everyone, the findings suggest that greening initiatives must be paired with broader efforts to address the root causes of social and economic inequality.