If the uncertainty or forced isolation of the coronavirus pandemic has you on edge, the best prescription for your stress may just be a “nature pill.” Research from the University of Michigan published in Frontiers in Psychology shows time in nature will significantly lower your stress hormone levels.
It may seem intuitive but this research is a good reminder for people looking for ways to alleviate pressure. Healthcare practitioners could start prescribing time outdoors for patients in need of a stress break after reading about the improvement seen in study participants.
"We know that spending time in nature reduces stress, but until now it was unclear how much is enough, how often to do it, or even what kind of nature experience will benefit us," says Dr. MaryCarol Hunter, an Associate Professor at the University of Michigan and lead author of this research. "Our study shows that for the greatest payoff, in terms of efficiently lowering levels of the stress hormone cortisol, you should spend 20 to 30 minutes sitting or walking in a place that provides you with a sense of nature."
Hunter and her team approached their research with the thought of effective dose durations and frequencies in mind. This was to aid practitioners with evidence-based guidelines they could use in making recommendations to patients.
A total of 36 urban-dwelling participants completed the 8-week trial. They were asked to have a “nature experience” of at least 10 minutes at least three times per week. Their levels of the stress hormone cortisol were checked through saliva samples taken before and after their experience every two weeks.
"Participants were free to choose the time of day, duration, and the place of their nature experience, which was defined as anywhere outside that in the opinion of the participant, made them feel like they've interacted with nature,” Hunter said. “There were a few constraints to minimize factors known to influence stress: take the nature pill in daylight, no aerobic exercise, and avoid the use of social media, internet, phone calls, conversations and reading."
The allowances built into the experiment were designed to hopefully extract meaningful data while taking into account the different schedules people with busy lives tend to live.
"Building personal flexibility into the experiment allowed us to identify the optimal duration of a nature pill, no matter when or where it is taken, and under the normal circumstances of modern life, with its unpredictability and hectic scheduling," Hunter said. "We accommodated day-to-day differences in a participant's stress status by collecting four snapshots of cortisol change due to a nature pill. It also allowed us to identify and account for the impact of the ongoing, natural drop in cortisol level as the day goes on, making the estimate of effective duration more reliable."
A 20-minute nature experience was enough to significantly reduce cortisol levels with the greatest benefit coming between 20 and 30 minutes. The benefits continued to accumulate after the 30 minute mark but at a much slower rate.
Hunter wants to continue her research to further develop the concept of frequency and duration.
"Our experimental approach can be used as a tool to assess how age, gender, seasonality, physical ability and culture influences the effectiveness of nature experiences on well-being,” Hunter said. “This will allow customized nature pill prescriptions, as well as a deeper insight on how to design cities and wellbeing programs for the public."