Those who relax three times a week in a forest or park can measurably reduce their stress and promote good health.
Meanwhile, there are many studies that prove the positive effects of a stay in nature or especially a forest walk. Already in 1984, the Swedish researcher Roger Ulrich speculated that possibly only the sight of trees could have a positive effect. He found that patients who looked out of the hospital window for surgery after surgery had fewer painkillers and recovered faster.
A Japanese study found that regular and extensive forest walks increased the number of natural killer cells in the blood, a subset of white blood cells, and part of the human immune system.
In 2015, the American environmental psychologist Marc Berman stated that the number of trees in a residential area can affect the health of the residents. Those who lived in greener areas suffered less often from cardiovascular disease or diabetes. The scientists also considered in this study and tried to out count that other factors, such as higher socioeconomic status or healthy diet and exercise, are also affecting health.
In Japan, the “Shinrin-yoku”, ie the “bathing in the forest”, is a part of the state health care, “forest medicine” is since 2012 a separate branch of research at Japanese universities. Here they also explore, which factors provide exactly for the positive health effects. Is it just in the air of the forest, in particular vegetation or other factors or their common occurrence?
Since 2017, there is also a certified spa and medicinal forest in Germany, on Usedom.
A recent study from the University of Michigan (Mary Carol R. Hunter, Brenda W. Gillespie, and Sophie Yu-Pu Chen, 2019, Urban nature experiences reduce stress in the context of daily life based on salivary biomarkers. Frontiers in Psychology, April 2019) shows that even a short walk can significantly reduce stress. Accordingly, 20 minutes in the open will be enough to significantly reduce the level of stress hormones.
The current research has shown that as little as 20 to 30 minutes in an environment that gives you a sense of nature suffices to effectively lower cortisol levels in the body. Cortisol, also known as stress hormone, is produced in the adrenal cortex and broken down in the liver. Permanently elevated cortisol levels, such as chronic stress, can lead to obesity, weaken the immune system, and promote cardiovascular disorders, depression and a host of other conditions.
The scientists at the University of Michigan had prescribed a regular “natural pill” to a group of 36 volunteers, including 33 women and three men: The subjects should undertake at least three walks a week in nature with a duration of ten minutes or more. Before and after the experiments, the participants took a saliva sample which was examined for both the cortisol levels and the so-called alpha-amylase. This enzyme is derived from the digestive tract and is known to give the body increased levels of stress.
Because the biomarkers change physiologically with the time of day, these daily fluctuations were taken into account in the calculation. The subjects were also not allowed 30 minutes before they took the saliva sample, to eat or drink, as food in particular can greatly influence the alpha-amylase.
The volunteers were able to determine the day, duration and location of their natural experience to suit their individual lifestyle. However, they had to minimize some stress factors, such as Do not do any sports exercises, avoid social media, the internet, phone calls, conversation and reading “, and the walks should be done in daylight.
After just 20 minutes of experiencing nature, the cortisol levels had dropped significantly in the subjects. The stress hormone was reduced most when participants spent about 20 to 30 minutes sitting or walking in a nature environment. The participants stayed even longer in the open air, the cortisol continued to decrease, but not as strong as in the first 20 minutes. In alpha-amylase, the difference was clearly measurable only in those subjects who barely moved while out in the open, sitting on a bench, for example.
The researchers await that their study highlights the positive effect of staying in nature. They see outdoor living as a cost-effective therapeutic tool to contain the negative effects of city life, such as spending time indoors and in front of screens.
https://www.frontiersin.org/articles/10.3389/fpsyg.2019.00722/full
