Nature is ingrained in our primal beings. We feel the intrinsic pull to be out into nature. Our bodies change with seasons, the rise and fall of the sun, the pull of the moon, and the weather. It is no wonder that city dwelling is linked to a rise in anxiety and mental disorders. We are not meant to be surrounded by concrete, polluted air, and white noise. The Douglas Mental Health University Institute at McGill University in Canada set out to figure out why our bodies respond positivity to nature and can take a detrimental turn in the city. They used functional magnetic resonance imaging to monitor the brains of 32 healthy adults.Those who lived in the city had increased activity in the amygdala part of the brain, which controls emotions such as fear. They also noted that people who lived in the city the first 15 years of their life had increased activity in their pregenual anterior cingulate cortex, which regulates the amygdala. Those who grew up in the city had a greater sensitivity to stress. Of course, there are other factors that play a role in the amount to stress and anxiety in ones city living life. It depends on the individuals ability to cope with city life and have control over their internal responses to external circumstances.
This is where nature comes into play. If a city dweller has access to nature they are less likely to develop mental illnesses and anxiety. A published research study found that people who took a 90 minute walk in nature versus a walk in the city showed lower levels of rumination. It also showed reduced neural activity in the subgenus prefrontal cortex, the area of the brain linked to risk of depression and anxiety. Other research shows that even viewing images of nature activates the brain associated with empathy. People would start to care more about others and the world around them versus viewing urban scenes which triggered blood flow to the fear associated amygdala. This fear causes anxiety and an emotional vortex.
Taking a quick nature retreat may provide physical and mental reprieve from the hectic urban settings. Another study (International Journal of Environmental Research and Publish Health) focused on the sympathetic and parasympathetic nervous system. These systems handle the stress either triggered by “fight or flight response”, or by enhancing feelings of calmness. Sensors were worn to track their heart rates and other functions when viewing green images or urban spaces. The images were shown before and after a difficult math exam, designed to raise stress levels. When green images were seen after the math test, the parasympathetic nervous system was activated and lowered the heart rate.
Of course there all the other benefits of nature I have mentioned in past blog posts. When anxiety is decreased then our physical bodies benefit. Nature improves focus, boosts creativity, leads to better workouts (levels of the stress hormone cortisol are lower when exercising outdoors verses indoors), and less pain and better sleep. Without good sleep our brain and body begin to shut down and are dysfunctional. When we are dysfunctional, anxiety will build due to poor performance in our work, studies, and personal life.