How 120 minutes of nature benefits your health

How 120 minutes of nature benefits your health

It take just that amount of time to get a dose of nature high enough to make people say they feel healthy and have a strong sense of well-being.

Precisely 120 minutes

A growing body of research points to the beneficial effects that exposure to the natural world has on health, reducing stress and promoting healing. Now, policymakers, employers, and healthcare providers are increasingly considering the human need for nature in how they plan and operate.

Metastudy

In a study of 20,000 people, a team led by Mathew White of the European Centre for Environment & Human Health at the University of Exeter, found that people who spent two hours a week in green spaces — local parks or other natural environments, either all at once or spaced over several visits — were substantially more likely to report good health and psychological well-being than those who don’t. Two hours was a hard boundary: The study, published last June, showed there were no benefits for people who didn’t meet that threshold.

The effects were robust, cutting across different occupations, ethnic groups, people from rich and poor areas, and people with chronic illnesses and disabilities.

Outdoors in nature can be good for people’s health and well-being

“It’s well-known that getting outdoors in nature can be good for people’s health and well-being, but until now we’ve not been able to say how much is enough,” White said. “Two hours a week is hopefully a realistic target for many people, especially given that it can be spread over an entire week to get the benefit.” The study by White and his colleagues is only the latest in a rapidly expanding area of research that finds nature has robust effects on people’s health — physically, mentally, and emotionally. Nature is not only nice to have, but it’s a have-to-have for physical health and cognitive function.”

Richard Louw on amount of research

“When I wrote Last Child in the Woods in 2005, this wasn’t a hot topic,” said Richard Louv, a journalist in San Diego whose book is largely credited with triggering this movement and who coined the term Nature Deficit Disorder. “This subject was virtually ignored by the academic world. I could find 60 studies that were good studies. Now it’s approaching and about to pass 1,000 studies, and they point in one direction: Nature is not only nice to have, but it’s a have-to-have for physical health and cognitive functioning.”

Nature is the antidote to stress

These studies have shown that time in nature is an antidote for stress: It can lower blood pressure and stress hormone levels, reduce nervous system arousal, enhance immune system function, increase self-esteem, reduce anxiety, and improve mood. Attention Deficit Disorder and aggression lessen in natural environments, which also help speed the rate of healing. In a recent study, psychiatric unit researchers found that being in nature reduced feelings of isolation, promoted calm, and lifted mood among patients.

Park deserts

Researchers and policymakers now talk about “park deserts” in urban areas. Cities are adding or enhancing parks, and schools and other institutions are being designed with large windows and access to trees and green space — or blue space, as in aquatic environments. Businesses are increasingly aware of the desire among employees for access to green spaces. “It’s needed to attract a skilled work force,” said Florence Williams, author of The Nature Fix. “Young people are demanding high-quality outdoor experiences.”

The forest is the therapist

One expert says he’s concerned that the growing interest in more contact with nature relies too much on only experiencing it visually. The global Association of Nature and Forest Therapy Guides shows clients how to use immersion in nature for healing. “The forest is the therapist,” the group’s slogan reads. “The guides open the door.”

Studies show that the effects of nature may go deeper than providing a sense of well-being, helping to reduce crime and aggression. A 2015 study of 2,000 people in the United Kingdom found that more exposure to nature translated into more community cohesion and substantially lower crime rates.

And while more vegetation is thought to encourage crime by providing security for criminals, another study found the opposite — vegetation abundance is associated with a reduction in assault, robbery, and burglary, although not theft.

Causality and research

Still, many of these studies are correlational rather than causal. That means it’s hard to show that natural landscapes cause these effects, though these things happen when people are in a natural environment. Sara L. Warber, professor of family medicine at the University of Michigan, noted that there are no “randomized, controlled studies” on the effects of nature on human health. Nonetheless, she said, there are epidemiological studies and measurements of before and after exposure to nature, and the results from this research are robust.

Attention restauration theory

What are the active ingredients in a dose of nature? Pioneers in this work, Rachel and Stephen Kaplan, who began studying the subject in the 1970s, devised Attention Restoration Theory, which holds that paying attention in bustling cities, at work, or in other stressful environments requires a good deal of effortful attention. In a natural environment, however, the Kaplans found that people paid attention more broadly and in a less effortful way, which leads to far more relaxed body and mind.

Shinrin yoku

Japanese researchers have studied “forest bathing” — a poetic name for walking in the woods. They suspect aerosols from the forests, inhaled during a walk, are behind elevated levels of Natural Killer or NK cells in the immune system, which fight tumors and infections. A subsequent study, in which essential oils from cedars were emitted in a hotel room where people slept, also caused a significant spike in NK cells. However this growing field might be defined, it is gaining momentum. In a recent paper, 26 authors laid out a framework to create a formal role for the positive impacts nature has on mental health and to formulate a model for conserving nature in cities and integrating it into planning for these health effects. “There is an awakening underway today to many of the values of nature and the risks and costs of its loss,” says one researcher.

Climate stress

Understanding nature’s therapeutic effects may be arriving at a propitious moment. Some studies have found that anxiety over climate change is a growing phenomenon. Ironically, one of the best antidotes for that might be a dose of green space.“If I am feeling depressed and anxious and worried about the environment,” Warber said, “then one of the best things I can do is go out in nature.”

Jim Robbins is a veteran journalist based in Helena, Montana. He has written for the New York Times, Conde Nast Traveler, and numerous other publications. His latest book is the The Wonder of Birds: What they Tell Us about the World, Ourselves and a Better Future. More about Jim Robbins →