How Trees Affect Neighborhood Health

More trees in a city block significantly improved health ratings

Having some extra foliage on your block could be as good for your health as a pay raise — or an anti-aging machine.

A recent study from the University of Chicago found that having more trees in a city block improved residents’ self-ratings of health — with residents even saying that having more trees felt the same as having more money or being younger.

"It seems living in a greener area can compensate [for less income],” said lead study author Omid Kardan, of the University of Chicago, in a press release. “The environment we live in has a big impact on our perception of wellbeing, but also objectively on our health outcomes. We have to take that information into account when conducting urban planning.”

Kardan and team compared high-resolution satellite imagery with tree data in Toronto, Canada. These researchers then conducted an online health survey of more than 31,000 Toronto residents.

An additional 10 trees on a city block improve residents' health ratings, with many reporting that the trees felt the same as having an annual income increase of $10,000. The trees also had the same effect as being 7 years younger in terms of health ratings.

Residents with chronic health problems, such as high blood pressure, obesity and high blood sugar, also reported feeling healthier when there were more trees on the block.

These residents were also surveyed on mental health problems — such as depression, anxiety and addiction — and other conditions such as cancer, migraines, arthritis and asthma. However, any link to green spaces was inconclusive.

While this study does not make clear whether what, if any, direct impact trees have on human health — or whether the link is merely correlated — Kardan said "it's probably a combination of both."

“For example, in our case you might say trees reduce air pollution, relieve stress and promote more physical exercise," Kardan said. "Through those mechanisms maybe these people get healthier. Or probably as these healthier people, compared to others with the same amount of money and everything, chose to live in a greener area."

This study was published in the July issue of Scientific Reports.

The TKF Foundation, the University of Chicago and the Tanenbaum Endowed Chair in Population Neuroscience at the University of Toronto, Dr. Tomas Paus, funded this research.

No conflicts of interest were disclosed.