This last week I have been lucky enough to spend time in the Victorian high country backcountry skiing. This time in a natural setting invariably improves my emotional and mental wellbeing. In reflection it’s a reboot for my soul, where the benefits seem to last for weeks until I am able to schedule my next nature fix. There are now more and more scientists researching the benefits of nature, or how “forest bathing” positively influences our health and wellbeing.
The term forest bathing is a translation of the Japanese movement “shinrin- yoku”. So strong is the movement that the Japanese Society of Forest Medicine has formally conducted research. Indeed the Japanese, Taiwanese and South Korean governments are investing heavily into this area. Of interest is that these nations are the big users of technology, and many of the populous are disconnected from the natural world.
A series of studies have measured cortisol, heart rate and blood pressure to demonstrate the measurable benefits of wellbeing and performance by simple contact with nature. Interestingly some Japanese research has shown that exposure to nature not only mediated the stress response, but also impacted the immune response. A group of Japanese businessmen had a 40% increase in natural immune “killer cells” after a walk in the woods. These killer cells are our immune systems first line defensive weapon against infection like the influenza virus. Interestingly these killer cells were still elevated by 15% over baseline figures one month later!
In the book “Your Brain on Nature: The science of nature’s influence on your health, happiness and vitality”, the authors a medical doctor and naturopath, cite various examples around the world supporting the title of their book. Among them, subjects in an aged care facility in Texas showed decreased stress hormones when in a garden setting; a study in Kansas using EEG showed less stress in subjects when plants were in the room; researches in Taiwan using measures like EEG and skin conductance noted therapeutic effects in subjects viewing natural settings; a group in Japan had lower heart rates after viewing natural scenes for 20 minutes; another 119 research subjects in Japan showed less stress response when transplanting plants in pots than they did simply filling pots with soil.
So what are the mechanisms for these reported changes to wellbeing?
In the 1970’s, research showed changes to alpha brain wave activity when participants drove along tree line boulevards instead of freeways. Alpha waves are associated with serotonin production and had a positive effect on depression, anxiety, anger and aggression. More recent, research into phytoncides- phytochemicals that are given off by trees and plants, showed they had a profound effect on the brain. Not only did they lower stress hormones, they regulated pain and reduced anxiety. Simply taking a walk in the forest and breathing deep was providing a direct chemical pathway to the brain via our olfactory system.
It appears that our brain has evolved in nature. There is only a minority of humanity that has existed for more than a couple of generations in a purely urban environment. Nature is ingrained in our DNA and neurobiology! Researches using fMRI have pinpointed where in the brain nature works its magic. In particular the parahippocampus gyrus, which is rich in opioid receptors. Nature is like a little drop of morphine to the brain!
But there are other benefits of being in the outdoors. Firstly, play in nature exposes children and everyone else to a full range of microbes to support a healthy gut flora and challenge and tune one’s immune system. Otherwise known as the hygiene hypothesis -where modern, urban people are showing a rapid increase in autoimmune disease because they live in an over sanitized environment. To be healthy our internal ecosystems need to be connected to external ecosystems.
Other researches propose the hypothesis that sleep disorders have become epidemic because of widespread Vitamin D deficiency. Being outdoors exposes people to the full spectrum of light, with a variety of benefits, not the least amongst them regulating melatonin and sleep cycles but also making healthy levels of vitamin D. Vitamin D deficiency is an epidemic in its own right, but in this light, it is the subject of the epidemic of nature deficit disorder!
So how do I get my nature fix? Prior to the birth of my son Samuel this involved regular weekends away camping and walking. These days I love gardening when at home or lying in the hammock enjoying the surrounding tree canopies. If I have more time, I enjoy a bushwalk with family in a national park close to Melbourne. A simple mindful walk in the Botanic Gardens or working out at Fawkner Park, is another great place to forest bath!
My wife Karen knows that I need a regular nature fix every 4-6 weeks to maintain emotional regulation at home and work. I am already planning my next mountain reboot within the next month. Apparently, I am not nice to be around when in nature deficit.
Your Brain on Nature: The science of nature’s influence on your health, happiness and vitality. Eva M Selhub MD & Alan C Logan
Go Wild: Eat fat, run free, be social, and follow evolutions other rules for total Health and wellbeing. John J Ratey MD & Richard Manning
The Nature Fix: Why nature makes us happier, healthier and more creative. Florence Williams