We’ve long known it’s refreshing to spend time outside in natural environments. Being cooped up inside can feel unnatural and increase our desire to get out. Taking a walk on a wooded path, or spending an afternoon in a park can have a noticeable impact on our mood.
Renowned biologist E.O. Wilson, creator of the biophilia theory, hypothesizes that people have an innate need to seek relationships with nature and other forms of life.
On an intuitive level, this makes sense. Humans have nearly always lived in open, natural environments. Our migration into cities has been a very recent phenomenon. It makes sense that removing us from the natural environment could affect our health. Now scientists are beginning to affirm what many of us already know.
Nature and Healing
Research in this area started in the 1980s with Robert Ulrich, a professor at Texas A&M University. His work looked at surgery patients who had a view of trees out of their window compared to those who had the view of a wall. Those with the natural view reported less pain and spent less time in the hospital.
Since then, several studies have shown a reduction in pain both through viewing natural scenes as well as looking at nature videos and pictures.
Other studies have looked at the effect of exposure to daylight has on patients and found they experienced less pain, less stress, and used fewer pain medications than patients not exposed to natural light. There is also preliminary evidence that hospital gardens can alleviate stress in both patients and their families.
Such findings have implications in designing health care facilities. There appears to be consistent evidence that exposures to natural environments have a positive effect on pain, stress, anxiety, blood pressure, and heart rate. In the Center for Health and Nature, a joint venture between my university Texas A&M, Houston Methodist Hospital, and nonprofit Texan by Nature, our new studies are assessing if these effects extend to the virtual world, including immersive virtual reality and virtual windows.
A Preventive Effect?
While nature appears to be helpful in restoring health after illness, can it actually help us stay healthy? Researchers across the world have been asking this question.
From forest bathing (“shinrin-yoku”) in Japan to the 30 Days Wild campaign in the United Kingdom, which encourages people to connect to wild places, people have been examining the healing powers of nature.
While walking is well established as a health-promoting behavior, studies now are examining if walking in natural environments is more beneficial than indoors or in urban environments. Results have shown positive effects on mental and physical health, including improved attention, better mood, and healthier blood pressure and heart rate. Several programs across the country have been formed to expose military veterans to natural spaces to combat symptoms of PTSD. In children, playgrounds with green space increased vigorous physical activity, decreased sedentary time, and even led to fewer fights.
While there is growing evidence that exposure to natural environments is beneficial to health, there are still many questions to be answered. What is nature? While this may seem simple at first glance, there are many differences between a national park, an urban pocket park, and a picture of waves crashing on the beach. What is the dose of nature needed?
For physical activity, there is a scientific consensus that people need 150 minutes a week for good health. How much and how often is exposure to nature needed for better health? How do longer doses versus shorter doses—such as a weekend camping trip in a forest versus a walk through a park—affect us? What sensory part of nature is affecting us? Is it sight, sound, smell, touch, or a combination of them?
A recent paper proposed enhanced immune function as the central pathway for the variety of positive health outcomes received from nature exposure. This still needs to be tested.
Despite the need for more research, the need for more nature exposure is urgent. The Environmental Protection Agency estimates that U.S. citizens, on average, spend 90 percent of their time indoors. A study in the UK found that children spend only half the time outdoors that their parents used to.
But there are efforts to fix this problem. The 30 Days Wild program run by the Wildlife Trusts in the UK encourages people to engage with nature every day for a month. In its first year, more than 18,000 people signed up. It starts again on June 1.
Doctors in Scotland now are able to give nature prescriptions to their patients. The educational leaflet they provide describes numerous monthly activities including touching the ocean, taking a dog for a walk, and following a bumblebee. In the United States, the Park Rx America program has been working to connect publicly available outdoor space to physicians to have them prescribe nature.
As spring arrives, it is time to make a commitment to spend more time in nature. Better health could be as easy as a walk in the park.
is a professor of public health at Texas A&M University. This article was first published on The Conversation.