You’ve likely heard trees being called the lungs of the planet. According to the environmental agency Environment Canada, each one can provide the daily oxygen for two people. That might make you wonder—have you been taking trees for granted?
With Earth Day just behind us and national Arbor Day here, it’s a good time for all of us to consider the little things we can do to help the planet. It’s also a time to reflect on the ways that doing so actually serves our own self-interests. Rich vegetation contributes to the happiness of future generations, but as science shows, it might also give you an edge. As it turns out, living near trees isn’t just an abstract metaphor for health. It’s literal health—and it has been shown to unlock peak performance.
The best part is, you don’t have to go full-on Henry David Thoreau to reap the goodness of nature. You can start small, by planting a tree today. Here’s your motivation.
1. Trees Cut Your Odds of Chronic Disease
A study published in the journal Nature found that people with 11 or more trees on their block have cardiovascular systems on par with people 1.4 years younger. And a study from Harvard found that compared to those with a lack of tree coverage, physically active women living in greener neighborhoods have fewer health complications. They're 41 percent less likely to die from kidney disease, 34 percent less likely to die from respiratory illness, and 13 percent less likely to develop a fatal cancer condition.
The reason? Partly it’s due to air quality: Those living in the greenest neighborhoods had less exposure to pollution. But that’s not the entire story.
2. Trees Motivate You to Stay Active
Another reason for the health boon is that living near greenery motivates you to keep moving. “We believe this is because nature offers opportunities to exercise,” says author of the Harvard study, Peter James, Ph.D. Makes sense. After all, it's more fun to run through a forest than it is to suck wind along a busy highway.
3. Trees Reduce Stress
Simply looking at foliage can lower the levels of stress hormones in your body, according to a study published in Landscape and Urban Planning. In it, men were given stressful tasks, like presenting an impromptu speech or taking a math test while their peers watched. (Sounds like your high-school nightmares, right?)
Afterward, the stressed-out participants were shown six minutes of nature through a virtual reality (VR) headset. As the tree-density increased in VR, levels of salivary cortisol, a stress hormone, plummeted.
But worth noting: When the virtual tree density became thick and overgrown, the participants stress levels went back up. That makes a decent case for your manicured lawn. “Green space that is poorly maintained actually increases stress and negatively impacts health and wellbeing,” says Patricia Landry, a parks official in Toronto, which is largely regarded for having the most health-affirming urban planning on the planet.
4. Trees Support Mental Health
Another finding from the Harvard study was that people in greener neighborhoods reported better mental health. This could stem from an evolutionary concept known as biophilia, which posits that humans are instinctually driven to seek nature. “Biophilia suggests that human beings have evolved to prefer certain natural environments that are essential to their thriving,” says James. And when you satisfy that drive, your mind has an easier time finding balance.
5. Trees Improve Your Social Life
Finally, the last big finding from the Harvard study was that healthy subjects in leafy neighborhoods are also more likely to be friendly with their neighbors. Why? Perhaps it's because trees offer an opportunity for conversation—you see your neighbors out raking leaves or trimming hedges, and you feel like you know them. Maybe you strike up a conversation. As the study notes, those small interactions correlate with feelings of safety and lower stress. Plus you might make some friends—and friendship confers a whole new litany of health benefits.
Help! I'm a City Dweller Without a Yard!
No problem! Balconies, stoops, and patios are great places to plant trees, says Heather McCargo, founder of the Wild Seeds Project, a nonprofit that aims to increase biodiversity in urban areas. She recommends small tree varieties like shadberry or black haw, which grow well in large pots that are 18 to 24 inches wide and deep.
“Some small trees may eventually outgrow their pots and need to be planted in the earth," she says. "But in the meantime, you can enjoy them."