When you are hiking, you can practice mindful meditation. Mindfulness is the practice of bringing one’s attention to the present moment. It is a mental state of focus and awareness on what is happening right now in front of you. It allows for calming and quieting the mind and bringing stillness to wandering thoughts. It acknowledges and accepts one’s feelings, thoughts, and bodily sensations.
Just by being and moving in a natural outdoor setting, you bring your awareness and focus to the present moment. You help to calm and still the rumination of an active mind and the endless rambling of many thoughts. You free yourself from the endless activities of urban living. You free your concentration from the incessant inclusion of digital devices on your mind and consciousness. You open and accept that you are a smaller part of an immense universe. You allow the energy and life-giving force of Mother Nature to flow into you. You accept and receive the healing power of nature.
Science is beginning to validate the healing power of nature. Several studies support this notion that is one of the foundations of naturopathic medicine. In this article, I focus particularly on the mental and emotional impact of nature on human health.
G.N. Bratman from Stanford University evaluated brain activity and scores on a questionnaire in 38 subjects. Nineteen participants walked 90 minutes in a natural lush green setting around Stanford University, and 19 other participants walked for the same amount of time through an urban setting with heavy traffic. Functional MRIs showing blood flow and brain activity were performed in each group of volunteers. The MRIs showed that those who walked in an urban setting had markedly increased activity in the subgenual prefrontal cortex. This was associated with increased stress, anxiety, and rumination of thoughts. Those who walked in the natural setting showed decreased activity in this area of the brain. These participants also reported less rumination, anxiety and showed more attentiveness and were happier than those who walked in the urban setting.
In an evaluation of three other independent studies, imaging tests showed that urban living increases the activity of the perigenual anterior cingulate cortex, which surrounds the corpus callosum in the frontal lobe, and the amygdala in the brain. The anterior cingulate cortex is believed to be involved in a wide variety of autonomic functions including blood pressure, heart rate, and certain higher level functions such as decision making, impulse control, and emotion. The amygdala consists of two almond-size regions in the deeper brain and is involved in emotional reaction, decision making, and memory. Increased activity of the amygdala was associated with increased levels of stress hormones, increased anxiety, increased mood disorder, and increased depression. No other areas of the brain were affected or showed increased activity with urban living.
In 2016, National Geographic published an expose of the positive effects of nature on human health. Psychologist David Strayer from the University of Utah showed that being in a natural environment decreased brain theta wave activity. This was associated with decreased heart rate, decreased stress hormones, and decreased protein biomarkers of stress. Swedish researchers showed that scenes of nature decreased heart rate variability quicker and allowed the heart rate to return to normal after a complex math test. Japanese researchers showed that those subjects who strolled in forests versus urban city centres had 16% less levels of the stress hormone Cortisol and showed slight decreases in heart rate and blood pressure. Korean researchers used functional MRIs to evaluate blood flow in different parts of the brain after viewing different pictures. Pictures of urban scenes increased blood flow to the amygdala, which is typically associated with fear and anxiety. Pictures of nature scenes increased blood flow to the anterior cingulate and insula, which are associated with empathy and altruism..