Forest Therapy

Paracelsus„The art of healing comes from nature, not from the physician.“

Shinrin yoku (derived from the Japanese shinrin’yoku = “forest bathing“), sometimes referred to as nature therapy or forest therapy, is a salutary method, which consists of spending time in nature with awareness in order to relieve stress, reestablish inner harmony and improve mental and physical health. Various physiological benefits have been proven by numerous studies, e.g., improved immunity function, balanced cardiovascular system, better sleep and decrease in depression and anxiety.

Nowadays, shinrin yoku makes up an inseparable part of the non-invasive and non-pharmacological medicinal approach, mainly in Japan.

Health benefits of forest therapy are above all demonstrated by the immune system and are attributed to volatile substances (wood essential oils) emanated from the trees. These substances possess antibacterial properties and probably contribute in regulation of the psycho-neuro-endocrine-immune pathways.

In one study, twelve subjects were tested before and after a three-day sojourn in a forest. The outcome showed that activity and number of the NK cells (NK – “natural killer”, responsible for the immune protection) increased by more than 50% after the forest-bathing. NK cells present a powerful immunity tool eliminating virus-infected- and tumor-cells. Therefore, increase in their number and activity is associated with an important immunity reinforcement.

Another study observed 12 subjects undertaking sessions in 24 different Japanese forests. Activity of the subjects’ physiological functions and stress-hormone levels were compared to that measured after interrelated sessions in the city environment. Results associated with the time that subjects spent in the forest environs displayed remarkable decreases in adrenaline, noradrenaline and cortisol levels, as well as in the blood pressure and heart rate. This refers to a shift from the sympathetic to the parasympathetic activity of the autonomic nervous system meaning the establishment of the relaxing state.

It is not surprising that forest environments provide salutary effects also on mental health. In 500 subjects, a one day sojourn in nature led to increased emotions of friendliness and wellbeing and decreased negative emotions including hostility and depression, compared to control evaluations.

Although health benefits of the forest are mostly attributed to chemical substances produced by trees, there is probably much more beyond this simple hypothesis.

Plants are living organisms subject to the same rules of Life on Earth as human beings. Like all living organisms, plants use deoxyribonucleic acid (DNA) as their genetic material and they emanate electrochemical potentials which can contribute to their interactions with other living forms.

Whatever the mechanism of the healing effect of nature is, it is highly advisable to benefit from its presence, especially in times of weak immunity or during stressful life-periods.

Summer time invites us to spend a lot of time in the nature. Forests offer fresh air, shade, birds’ singing, cool water streams, and delicious forest fruits.

Keep in mind that “Half day in a forest = half of the worries!”

For more detailed information about Shinrin Yoku including scientific references, please go to the “Applied techniques” section => Forest Medicine.

July 14th, 2023

Author Kristina Höschlová