EXETER, United Kingdom: People who experience nature for at least 120 minutes per week are more likely to report good health and psychological wellbeing, a large UK study suggests.
Researchers found that it didn't matter how participants achieved their total time outdoors, whether in one long stretch or several short visits, but the greater the weekly "dose" of nature exposure up to about 300 minutes, the bigger the benefit.
"Doctors (and patients) are often quite aware that spending time in natural environments might be good for people's health, but the question that keeps coming up is, 'How much is enough?'" said lead study author Mathew White of the European Centre for Environment and Human Health at the University of Exeter Medical School in the UK.
"Our aim was to take a step in answering this simple, sensible question," he told Reuters Health by email.
"Common sense, really."
White and colleagues analyzed 19,800 responses in 2014-2016 to a UK government survey assessing "engagement with the natural environment" in a nationally-representative sample of residents of England.
Participants were asked about their contact with nature during the previous week, including parks, nature areas, beaches, farmland, hills and rivers, but not including routine shopping trips or time spent in their own garden.
They were also asked about their health and wellbeing with the questions, "How is your health in general?" and "Overall, how satisfied are you with life nowadays?"
White's team found that people who spent two hours in nature during the last week had 23 per cent higher odds of reporting high wellbeing and 59 per cent higher odds of reporting good health compared to those with no nature contact.
The positive effect increased with additional time outdoors, peaking at about three hours per week for health and five hours per week for wellbeing.
The researchers adjusted for gender, age, health problems or disability, as well as socioeconomic factors and local air pollution levels, but the effect held for all kinds of people.
"The most surprising thing for us was just how consistent the pattern was across lots of different groups in society, including old and young, male and female, rich and poor," White said.
"For us, the most important was also the same pattern for people with long-term illness or disability. It benefits everyone."
The survey participants who reported better health and wellbeing and who spent two to three hours in nature per week were more likely to live near neighborhood greenspace, to meet recommended physical activity guidelines and to have an occupation with a higher socioeconomic status, the researchers note in the journal Scientific Reports.
"This has implications for our greenspace and how we design towns and cities, as well as street trees and backyards," said Richard Fuller of the Centre for Biodiversity and Conservation Science at the University of Queensland in Brisbane, Australia, who wasn't involved in the study.
"The difficulty in studying this area, however, is that it's tough to experiment other than on a small scale," he told Reuters Health in a phone interview.
"It's harder to study cause-and-effect with nature on the street, in a park or during our lived experience."
Future studies should include a long-term look at how changes in weekly nature exposure affect health and wellbeing, White said. Since these studies can often be difficult to measure and are expensive, it may be a few years before researchers can offer scientific guidelines, he added.
Researchers also want to know in what ways nature affects health and if different people respond in different ways to different types of nature, Fuller said. A football field is considered greenspace, for instance, but it may not offer the same nature-related benefits as a park or forest. At the same time, it's simply important for people to go outside, he added.
"Nature is good for us. Let's get outside, especially with the growing concern around spending time looking at computers all day," he said. "It's fun and easy and makes us feel good."