(CNN) – Nature does the body good. And a sprawling new analysis of more than 8 million people suggests that to boost residents’ longevity, cities should get a lot less gray and a lot more green.
Urban dwellers who live in close proximity to greenery are less likely to die before their life expectancy, per the findings of a new Lancet Planetary Health study. The authors call it the largest of its kind.
Researchers tracked the millions of people across seven countries, including the US, throughout their lives, and found that no matter the location on Earth or type of “green,” living near nature yielded similar health benefits globally, said study author David Rojas-Rueda, a researcher at the Municipal Institute of Medical Research in Barcelona, Spain.
Rojas-Rueda defined “green space” quite literally: He and his team identified green patches of land using satellite images. Vegetation and size of green spaces varied across the world, from public parks to grassy backyards.
It’ll take future studies to whittle down the types of green spaces that produce the healthiest people, he told CNN.
Green is good
The health benefits of greenery are broad and varied.
Green spaces like parks are excellent venues for physical activity, another health-boosting activity, Rojas-Rueda said.
Vegetation can act as a buffer between residents and blaring city racket, even if it’s as simple as a tree-lined street. Plants also help regulate temperature and extremity of environments, tempering the effects of climate change, he said.
More research is needed to determine the most evident benefit of urban green spaces. Narrower studies have already outlined a few significant improvements.
A 2016 study found that US women living in areas with the dense greenery had 12% lower death rates than women in less green spaces.
That study’s authors laid out specifics: Women who lived among lush greenery had a 41% lower death rate for kidney disease, 34% lower death rate for respiratory disease (trees’ leaves trap air pollutants) and 13% lower death rate for cancer.
Cities are already getting greener
For policymakers on the fence about greenifying cities, Rojas-Rueda said the health rewards far outweigh the costs.
Several major cities are already following his lead: New York has successfully turned 27% of its land into public green spaces, leading major cities in the US, per data from the World Cities Culture Forum. Paris is going a step further, vowing to turn one-third of its public green spaces into sustainable urban farms, running rampant with chickens, beehives and vegetables.
But if public green spaces are absent, filling backyards and living spaces with plants can yield similar benefits, he said.