The Neuroscience of Nature Mind and Health

Innerwealth Personal Mastery recommends business executives take a walk at lunch time in nature. It increases productivity, libido, wellbeing, raises the immune system and recuperates tired mind to enable a productive afternoon and warm homecoming at night. Here’s the science behind a bit of it.

Neuroscientists have found that views of complex, dynamic natural scenes trigger many more interactions of the mu (opioid) receptors in the large rear portion of the visual cortex. Viewing nature is literally a pleasurable experience. Views with less visual richness, such as a blank wall or a tree-less street, are processed in the small forward portion of the visual cortex and trigger far fewer of the mu receptors, triggering less pleasurable mental reactions (Biederman & Vessel, 2006). In contrast, movement in a natural setting, such as waves, leaves in a breeze, sh swimming in an aquarium, or a flickering fire, capture and hold our attention.

Other physiological effects of exposure to nature are well documented. For example, the effects of walking through forest atmospheres versus urban areas have been documented by comparing the salivary cortisol, blood pressure, and heart rate of subjects. On average, salivary cortisol (a stress hormone) was 13.4-15.8% lower, pulse rate was reduced by 3.9-6.0%, and systolic blood pressure was lower in individuals who walked through the forest, compared with those who walked through urban areas. Most impressive, overall parasympathetic activity— which occurs when we feel relaxed— increased by 56.1%, whereas sympathetic activity—which occurs when we feel stressed—decreased by 19.4% in subjects who walked through the forest (Park, 2010). These studies support Kaplan and Kaplan’s Attention Restoration Theory (ART): that nature serves as a positive restorative environment for humans and is an effective platform for stress management, health promotion, psychotherapy, and disease deterrence.

Reducing Stress

Stress is a known cause of both mental health disorders and cardiovascular diseases. According to the World Health Organization, mental health disorders and cardiovascular diseases are expected to be the two prime contributing factors to illnesses worldwide by 2020 (WHO, 2008). Treatment for cardiovascular disorders account for $1 of every $6 spent on healthcare in America (cDc, 2011). If workers are faced with nowhere to relieve stress in the of ce, the premature onset of psychiatric, stress-induced, and anxiety-related illnesses can surface (cDc, 2011). Studies show that our ability to directly access nature can alleviate feelings of stress, thus bolstering the case for biophilia in the workplace (Grahn & Stigsdotter, 2010). Heartbeat has been measured in natural and urban environments in relation to spatially selective attention. After test subjects viewed videos of the two aforementioned environments, their heart beat interval results suggested that videos depicting natural environments had an involuntary relaxing effect on autonomic functions, inducing positive cardiac deceleration as well as bene cial physiological arousal (laumann et al., 2003).

Forest Bathing – Shinrin-yoku

An emerging field of research surrounding human interactions with nature, known as Shinrin-yoku in Japan, continues to provide solid evidence of the benefits of natural environments on human health.

Shinrin-yoku is the ancient Japanese practice of restorative walks through natural settings, most often forests. In English, Shinrin-yoku directly translates to “forest bathing”.

Forest bathing experiments were conducted among 87 non-insulin-dependent diabetics over the course of six years to test Shinrin-yoku’s ability to effectively decrease blood glucose levels in patients. After walking 3-6 kilometers in the forest, blood glucose levels dropped on average from 179 milligrams to 109 milligrams. To ensure that this was attributable to the forest environment, rather than simply the aerobic activity of walking, patients were also monitored while exercising on indoor treadmills and in indoor pools. compared with these forms of exercise, which effectively reduced blood glucose levels by 21.2%, forest bathing decreased blood glucose by an impressive 39.7% (Ohtsuka, 1998). Within forests, human hormonal secretion and autonomic nervous functions are stabilized as we breathe in organic compounds called phytoncides excreted by the forest.

New Shinrin-yoku studies show that inhaling these pungent compounds has tremendous health benefits that are difficult to reap in the urban and built environments that confine so many individuals today.