Blog originally published September 9, 2018. Updated with more research articles October 15, 2023
Using Nature as medicine. How Nature improves human health and well-being.
Nature is all around us. Yes, the amount of Nature may be shrinking rapidly, but so far Nature is still all around us.
Whether it is a green space we see outside our post-operative recovery room after having had our gallbladder taken out. Whether it is a green roof we see looking down from our high-rise office building in the city. Whether it is a small neighborhood park in our big city. Whether we live in a rural area closer to Nature. Whether we visit a wilderness area or a national park.
Nature heals and should be used as medicine. One example is research “has shown that “symptoms” of ADHD are reduced after exposure to natural views and settings.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448497
Nearly 100 high quality scientific medical journal articles have been published regarding how Nature is able to heal humans and prevent chronic diseases. Unfortunately for humans, this information is more well known and utilized by landscape architects and city planners than by the medical profession.
Doctors, medical professionals in general and patients themselves need to start using Nature as medicine. People need to know that Nature has profound positive health benefits and should be used as such. For example, research shows “Interacting with Nature Improves Cognition and Affect for Individuals with Depression” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3393816/
Some people may say, “What is so important about that neighborhood park and playground or that buffalo in that national park?” “We humans have more important things to do than hang around those places.” Well, maybe not. Maybe these places are some of the most important and cost effective tools we have for optimizing human health and well being.
As you will see, many of these studies talk about about the positive impact on cortisol. One example is a study called “Effect of forest bathing trips on human immune function” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2793341/
Cortisol is called the “stress hormone”. It is made by our adrenal glands which sit on top of our kidneys. Cortisol has a profound impact on the development of autoimmune diseases as well as immune system dysregulation in general. Thus, it’s impact on cancer development, infections, allergies and asthma. Cortisol issues also impact chronic disease development of all kinds. Mayo Clinic lists several symptoms associated with excessive cortisol production including anxiety, depression, digestive problems, headaches, sleep problems, weight gain and memory and concentration impairment. Fatigue is also a very common symptom of cortisol disruption.
Because cortisol then disrupts the HPA axis (hypothalamus/pituitary/adrenal), this is the central mechanism for so much of chronic disease. But by correcting this cortisol issue, it can also become the central mechanism in reversing chronic disease or preventing disease in the first place.
In the compendium “Health and Healing Though Nature” that I put together with the help of a great medical student, all the studies referenced were arranged as 4 concentric circles surrounding a person’s home or work space. Rather than just a list of studies, this seemed like a much more functional arrangement and one that highlights how easy it is to access Nature no matter where a person lives.
So what kind of Nature can a person access and how will it positively affect their health and well being? As a person travels farther from home, what new options are available to get this impact on health and wellness. Or what options are available for someone living in a rural community or away from any town. The 4 concentric circles of Nature access radiating out from our homes and offices are as follows: In and around the home. In the local community. Rural or the greater wilderness area. Wilderness access.
Let me give a couple examples from each of these divisions.
1. “In and around the home”
Human response to window views and indoor plants in the work place. Hortscience 40 (5), 1354-1359. Chang, C.Y., Chen, P.K., 2005. RESULT: less anxiety and nervousness.
The nature of the view from home. Environ. Behav. 33, 507-542. Kaplan, R., 2001. RESULT: increased satisfaction with the neighborhood. Increased sense of well being.
Home gardeners value stress reduction and interaction with nature. In: Relf, D. (Ed.), Expanding Roles for Horticulture in Improving Human Well-Being and Life Quality, pp. 269-275. Catanzaro, C., Ekanem, E., 2004. RESULT: decreased physiological and psychological stress.
2. “In the local community”
Effect of exposure to natural environment on health inequalities: an observational population study. Lancet 372, 1655-1660. Mitchell, R., Popham, F., 2008. RESULT: stress relief due to lower levels of the “stress hormone” cortisol.
Physiological and psychological responses of young males during spring-time walks in urban parks. J. Physiol. Anthropol. 33 (1), 8. Song, C., et al., 2014. RESULT: decreased heart rate. Better mood.
Physiological and psychological effects of viewing urban forest landscapes assessed by multiple measurements. Landsc. Urb. Plan. 113, 90-93. Tsunetsugu, Y., et al., 2013. RESULT: decreased sympathetic (“fight or flight”), increased parasympathetic (“calming”), and increased mood.
3. “Rural or the greater wilderness community”
Morbidity is related to a green living environment. J. Epidemiol. Community Health. 63 (12), 967-973. Maas, J., et al., 2009a. RESULT: decrease in cortisol (the stress hormone). Reduction in death rate. Improvement in respiratory diseases. Increased survival after stroke. Decreased obesity rates in women. Decreased rates of obesity and being overweight in general. Decreased cardiovascular and respiratory death rates in men.
Nearby nature: a buffer of life stress among rural children. Environ. Behav. 32, 311-330. Wells, N.M., Evans, G.W., 2003. RESULT: decreased impact of stress.
Regulation of the immune system by biodiversity from the natural environment: an ecosystem service essential to health. Proc. Natl. Acad. Sci. USA 110 (46), 18360-18367. Rook, G.A., 2013. RESULT: decreased death rates, cardiovascular disease and psychological problems. Decreased endocrine (hormone) problems.
4. “Wilderness”
Wildlife tourism: the intangible benefits of human-wildlife encounters. Curr. Issues Tour. 12, 451-474. Curtin, S., 2009. RESULT: deep emotional response. Improved spiritual and psychological health.
Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest): using salivary cortisol and cerebral activity as indicators. J. Physiol. Anthropol. 26 (2), 123-128. Park, B. J., et al., 2007. RESULT: decreased prefrontal cortex activity in the brain after forest walking. Decreased cortisol (the stress hormone) before and after walking in the forest.
The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan. Environ. Health Prev. Med. 15, 18-26. Park, B. J., et al., 2010. RESULT: decreases blood pressure, cortisol (the stress hormone), heart rate.
The science speaks for itself.
Now we have to listen to what the science is telling us. Right outside our doors and even within our own homes and offices is one of the most powerful healing modalities that exists…NATURE.