FOREST BATHING - WHY NATURE IS HEALING

Deep breaths of fresh mountain air, rosy cheeks, trickling tickles of sun through the trees, silence broken only by birds singing and twigs breaking beneath your feet. The moments you have outdoors force you to be present, and the thoughts that grab you are, ‘how great this feels’, and ‘why you don't do it more’.  Nature has a calling to us, it does something to us. You feel it when you sit on the grass in your backyard, when you go for a hike, or, like my fellow tree-planters, part of why you feel that draw to go back year after year.

But what IS that exactly? What is actually going on in our physiology? And why is it something that everyone feels?

Like a mother to her little chicks, mother nature sees us. In our daily rat-race; stressed, depressed, overwhelmed, and overworked. Often we reach for technology, junk-food, medication, or material things to cure us of what we think will ease the pain and pressures of life. Now I do recognize that there are times when medication, or some sort of intervention is needed, but before you dismiss forest walks as an alternative prescription for what might ail you, “imagine a therapy that had no known side effects, is readily available, and could improve your cognitive functioning at zero cost” (Williams 2016), it’s called time in nature, and it’s science.

In a recent article in National Geographic, Florence Williams (2016) interviews cognitive psychologist David Strayer who states that the antidote to what modern life does to us, is Nature.  Due to large scale public health problems that stem from too much time indoors, such as obesity, depression, and increasing amounts of near-sightedness, more and more scientists are looking at how nature effects our brains and bodies (Williams 2016).  With advances in neuroscience and psychology, scientists are able to quantify things like stress hormones, heart rate, brain waves, or even protein markers that “indicate that when we spend time in green space, that something profound is going on” (Williams 2016).

Nature works mainly by lowering stress, but as I try to emphasize with my patients that I work with as a student clinician, stress is nothing to scoff at. It may seem like cop-out term, but as I will discuss in a blog to follow, stress has the most profound ripple effects in the body. From your immune system, to your brain chemistry, to direct physical effects, relieving your body from stress will change your human experience and abilities.

“Shinrinyoku” is Japanese for a forest bathing trip, which is a short leisurely visit to a forest, and is seen as similar to natural aromatherapy (Li 2010).  A study was conducted to look at the effects of forest bathing trips on human immune function.  Through a series of blood and urine samples taken before, during, and after a 3-day/2-night trip to forest areas, they found that immune markers were significantly higher during their time in the forest, and that some markers stayed high for up to 30 days after the trip (Li 2010).

Beyond the benefits for mild bouts of depressed feelings, or difficult moments, time in nature has proven to be effective even for those diagnosed as having Major Depressive Disorder. Berman et al. (2012), conducted research on if walking in nature would be beneficial for people with MDD, and found that participants showed an increase in memory span, and increases in mood not associated with the memory effects.  Not only do people report these effects subjectively, but they can be measured and seen as well.

Researchers in Korea used a series of MRI scans documenting the brain activity of people looking at a variety of different images (Williams 2016).  When volunteers looked at urban scenes, their brains showed more blood flow to the amygdala, which is responsible for fear and anxiety, yet when they saw natural scenes, their anterior cingulate would light up (Williams 2016). This region of the brain is responsible for empathy and altruism suggesting that maybe nature makes us nicer and more calm (Williams 2016).  Another group of researchers at Stanford also scanned the brains of 38 volunteers before and after they went for only a 90 min walk in either a large park, or downtown (Bratman et al 2015). They reported that those who walked in nature had decreased activity in the subgenual prefrontal cortex of the brain which is tied to depressive rumination (Bratman et al. 2015).  Not only can we measure the effects nature has on the brain, but our physiology as well.

According to a study published in The International Journal of Environmental Research and Public Health, even just 2hours of forest therapy reduces blood pressure, lowers cortisol, relieves tension and anxiety, and improves mood (Ochiai et al. 2015).

In the National Geographic article, Strayer discusses how your brain is not a tireless machine, but something that does get fatigued. He states that after time in nature, it is like your mental windshield gets cleaned, and you perform better, become more creative, and feel restored (Williams 2016).

As the statistics tell us that we spend less and less time as a whole out in nature (Engelmann 2001), and as we spend more and more money as whole on public health initiatives, maybe we should consider that one of the cheapest and most beneficial actions we can take is literally out your back door.

For some of us access to green spaces is not as easy as it is for others, but for your long-term health goals, it would be something to consider to put in your future plan. “Moving to greener urban areas was associated with sustained mental health improvements, suggesting that environmental policies to increase urban green space may have sustainable public health benefits” (Alcock et al 2014). So whether you budget for taking more trips into nature, or look to move into greener areas in the future, it might be something worth taking a serious look at.

Although science is starting to put these benefits into context and something that is measurable, there is still something mysterious about what being in nature does to us. This mystery is likely personal, and will never be fully tangible or understood, but I think I would like it to remain that way. Why we go out and seek time in nature is not because science tells us it is good for us, but because every single person out there knows how it makes them feel. We are a part of Mother Nature, and she is a part of us, there is no other reason we need to understand why she feels like home.
She knows, and so do you.

References
Alcock, I., White, M. P., Wheeler, B. W., Fleming, L. E., & Depledge, M. H. (2014). Longitudinal effects on mental health of moving to greener and less green urban areas. Environmental Science & Technology, 48(2), 1247-1255. doi:10.1021/es403688w

Berman, M. G., Kross, E., Krpan, K. M., Askren, M. K., Burson, A., Deldin, P. J., & ... Jonides, J. (2012). Interacting with Nature Improves Cognition and Affect for Individuals with Depression. Journal of Affective Disorders, (3), 300.

Bratman, G. N., Daily, G. C., Levy, B. J., & Gross, J. J. (2015). The benefits of nature experience: Improved affect and cognition. Landscape And Urban Planning, 41. doi:10.1016/j.landurbplan.2015.02.005

Engelmann, W. (2001). The National Human Activity Pattern Survey (NHAPS): A resource for assessing exposure to environmental pollutants. Journal Of Exposure Analysis And Environmental Epidemiology, (3), doi:10.1038/sj.jea.7500165

Li, Q. (2010). Effect of forest bathing trips on human immune function. Environmental Health And Preventive Medicine, (1), 9.

Ochiai, H., Ikei, H., Song, C., Kobayashi, M., Takamatsu, A., Miura, T., & ... Miyazaki, Y. (2015). Physiological and psychological effects of forest therapy on middle-aged males with high-normal blood pressure. International Journal Of Environmental Research And Public Health, 12(3), 2532-2542. doi:10.3390/ijerph120302532

Selhub, E. M., & Logan, A. C. (2012). Your Brain on Nature: The Science of Nature's Influence on Your Health, Happiness and Vitality. Hoboken: Wiley.

Williams, F. (2016). This is your brain on nature: when we get closer to nature--be it untouched wilderness or a backyard tree--we do our overstressed brains a favor. National Geographic, (1). 48.