“The art of healing comes from nature, not from the from the physician” 16th Century Century physician, Paracelsus
Getting out into the natural environment is an essential part of human well-being. I always feel more invigorated outdoors, whether it be in the forest, the mountains or ocean. Preferring to take my exercise in that space rather than a gym or urban pathway.
Should we all be trying to get some nature time each week?
I recently read an article in the Guardian citing a paper in Environmental Research. The authors used modelling and meta analyses to estimate that excess global deaths in 2012 attributable to fine particulate matter from fossil fuel combustion was a staggering 10.2 million(1). 65 % of these were in China.
I had read a more conservative estimate in a Lancet 2019 article reporting an annual 4.2 million deaths due to air pollution.
Either way, these numbers are astounding.
I found myself reflecting on how our environment affects us on a local level, even if we are not living in the obviously polluted atmosphere of a large Chinese or Indian city.
I wondered about the evidence supporting that feeling that getting back to nature was healthy.
How good is exercising in nature compared to walking or running along a busy roadway?
The Japanese have a term Shinrin-Yoku, or forest bathing. This practice of mindful forest visitation has been adopted as a way of reducing the stress of urban life since the 1980's and since then numerous studies have examined its effects. An extensive 2017 review of the current literature supports what we intuitively know about forests and green spaces: they are good for us (2).
Independent of the effect of exercise, cardiovascular markers of stress improve including resting heart rate, blood pressure and heart rate variability. A small randomised control trial even showed improved cardiac function in patients who had coronary artery disease when they were exposed to a week of 30min daily nature sessions.
Another systematic review and meta analysis of green spaces within urban environments has demonstrated in these regions a reduced incidence of type 2 diabetes, hypertension, low frequency heart rate variability, salivary cortisol, all cause mortality ,stroke , coronary artery insufficiency, dyslipidaemia and asthma.
Blood glucose levels were reduced in type 2 diabetes patients after multiple Shinrin-Yoku visits.
Psychologically, forest bathing and access to green spaces reduce stress, anxiety and depression scores in urban dwellers.
A single visit to the "forest environment enhanced human natural killer (NK) cell activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days " (3). It is proposed that these effects may in part be related to volatile plant chemicals known as phytoncides.
Since the first homonids appeared between 5 and 2 million years ago, we have existed in urban environments for less than 0.01% of our time on the planet. We are a species with persistent attachment to and are part of the natural world. It is proposed that we have an innate connection to the natural world and that it is important to our development and well being.
So it seems that the science is slowly catching up with our intuition.
Time in the forest and nature both makes us feel good and is good for us.
My take from the literature is that we should endeavour to get outside to a truly natural environment at least once a week.
If you can, do a short walk in a green space daily. A park in a city is better than the concrete jungle. The intensity of your effort in the natural space may not be as important as you being mindful of being there.
Be open to all the senses: the sounds of the forest, the smell of the leaf litter, the vista of the hills in the distance, the feel of the texture of bark and stream, the taste of wild berries . Blue space is also independently good for you: open skies, blue oceans .
If you can, make your weekly long slow exercise in the outdoors. A long hike, bike or paddle. Earn your turns skiing. Learn to surf. And know that nature is medicine.
Yes, you really do need to get out more.
Are you interested in reclaiming the outdoors?
Join the Primal Regeneration Outdoor Community.
Karn Vohra, Alina Vodonos, Joel Schwartz, Eloise A. Marais, Melissa P. Sulprizio, Loretta J. Mickley, Global mortality from outdoor fine particle pollution generated by fossil fuel combustion: Results from GEOS-Chem, Environmental Research,2021.
Review :Shinrin-Yoku (Forest Bathing) and Nature Therapy: A State-of-the-Art Review . Margaret M. Hansen *, Reo Jones and Kirsten Tocchini . Int. J. Environ. Res. Public Health 2017, 14, 851; doi:10.3390/ijerph14080851
3. Effect of phytoncide from trees on human natural killer cell function. Q Li et al. Int J Immunopathol Pharmacol Oct-Dec 2009;22(4):951-9.
