Have you ever felt a sense of peace as you walked in Nature, through contact with the elements of the forest, between ferns, moss-covered rocks and majestic trees? Breathing in the smells of resin, of leaves and humus, your nose wanders and your eyes roam the woods, finding surprises there every time, new objects of curiosity.

Japanese scientists have studied this feeling of serenity, of appeasement of the senses in a naturel environment, through environmental science and more specifically through forest bathing, i.e. tree therapy.

In his book “Shinrin Yoku”, literally “Forest baths”, professor Yoshifumi Miyazaki explains and expounds on the results of studies on the effects on the human body as it is exposed to a natural environment.

With a world population that in 2050 will be 68% urban according to the UN, scientists are exploring the relationship between well-being and Nature. And indeed, our body still seems to be sensitive to its natural environment as demonstrated by the results we are about to discover. Since humans hail from Nature, although they distance themselves from it by living in cities, they feel a deep, genetic need to nurture this essential and regenerative bond.

In chapter five of Shirin Yoku, “Ecotherapy and Science” crucial issues are brought to light.

Firstly, let us focus on the nervous systems of the human body. Stimulation, whether auditive, visual or other, triggers brain activity, which can lead to stress in case of overstimulation. Relaxation is therefore a reduction of brain activity.

In case of strong brain activity, the sympathetic nervous system boots its activity whereas the parasympathetic nervous system reduces it. The parasympathetic nervous system for its part increases its activity when the brain relaxes.

Thus the activities of the sympathetic and parasympathetic nervous systems are indicative of the level of stress and stimulation of an individual in a given situation.

Yet what is even more interesting is to note that the more energy the human body invests in the activity of the sympathetic nervous system as it deals with stress, the less the immune system of the body performs. Thus a weakened production of white blood cells, natural killer cells, can be observed in case of stress experienced by the human body.

Between 2005 and 2017, a comparative study was conducted in Japan by the Centre for Environment, Health and Field Sciences of the university of Chiba.

By placing individuals in towns and in forests with “Shinrin Yoku”, body indicators relating to stress and therefore to the well-being of the body were compared. The individuals had to walk and contemplate alternately in town and in the forest.

It then appeared that the blood pressure as well as the heart rate of the individuals living in forests were lower. But also that the stress hormone, cortisol, was less concentrated in the saliva of those individuals.

The activity of the sympathetic nervous system diminished too, while the parasympathetic nervous system increased, producing a sensation of well-being, vitality and an improved emotional state by curbing anxiety. The parasympathetic nervous activity even increased by +102% as a result of a simple fifteen-minute stroll in the forest.

Shinrin Yoku had therefore produced a state of physiological relaxation, unlike the urban environment that subjected the bodies of individuals to various tensions.

There is therefore a causal link between Nature and the human body which, placed in a forest rejuvenates and soon recovers its physiological and psychological health. Practicing forest bathing cannot cure all ills, however, the Japanese scientists who conducted those studies recommended it as a means of preventing a weakened immune system and stress in people.

In view of the results of this methodical work, we should reassess the relationship of the body to natural environments and review our relationship to our own body. Reconnecting to Nature and to our own Nature then appears to be a simple, sensible and easy-to-adopt idea. Recharging our batteries in Nature, in the middle of the forest and the trees, has never been so invigorating.