How Forest Therapy Helps People

By Martyna Lazowska

“A forest is a living thing like a human body. Each part depends on all the other parts.”  Louis L’Amour

The notion of shinrin-yoku is about immersing yourself in the forest atmosphere while walking, using all five senses. It allows you to focus on what is here and now. At a time when the boundaries between home and workplace have become blurred, being present in a specific situation is especially difficult. Absorbing the forest allows you to establish a personal and ethereal relationship with it, and ultimately to relax, clear your head, and improve immunity. According to Japanese scientists who have studied the influence of the forest not only on well-being, but also on health. In this essay, I am going to refer to some research around the benefits of forest therapy. 

The precursor and one of the main researchers of resistance in forest therapy is Dr. Qing Li, an immunologist and scientist from Nippon Medical School in Tokyo. In 2006, he published a study in which he proved that the activity of NK immune cells, i.e. natural killers, after exposure to Forest phytoncides is significantly higher. For example, as a result of stress NK levels will be reduced, they regenerate quickly in contact with forest air. What is important, it has been shown that the increased level of cortisol that the body produces under the influence of long-term stress is associated with low activity of NK cells that protect the body. This may suggest why immunity decreases with chronic stress not only in infections but also in the fight against cancer- the better the mental state of the person at risk, the better the body will react in emergency situations under the influence of forest air. The substances used to fight pathogens and even cancer are also produced. Granulysin also damages the cell membranes of harmful microorganisms and granzymes are involved in the digestion of proteins Dr. Qing Li has shown in many studies that after forest baths the activity of NK cells increases in a statistically significant way not only at the level of the activity of NK cells, but also cells secreting perforins, granulysins and granzymes A and B. He also discovered that if we take a forest walk once a week, our immunity will improve for the next week, and the weekend study devoted to forest therapy, they walked about 2 hours one day, and the next day they had two such sessions, it will help for another month.  

The same researcher and his team discovered three very interesting phenomena. Forest therapy raises the basis of the body's immunity, facilitates the regeneration of immunity if it has been weakened, and in some way, protects against a decrease in immunity, even under risky conditions. The experiment was carried out in laboratory conditions where the subjects inhaled the fragrances of trees and also in the field. One group walked in the forest, the other group stayed in a highly urbanised area. As it turns out, the walks around the city, despite the same physical effort, did not improve immunity in any way. Therefore, it turned out that this is not about physical activity, but the body's immersion in ‘a cocktail’ of forest substances produced by trees.  It is worth mentioning that similar results were observed in studies of Japanese medical school employees who were tasked with staying overnight in a hotel where tree fragrances were sprayed. As a result, their immunity also improved significantly, the increased level of NK cells has been noted. They also slept longer and were less tired the next day.

Another scientist researching the influence of forest baths on immunity is Gen- Xiang Mao, Chinese doctor from Zhejiang. He has devoted himself to work on another aspect of the immune system. He has dealt with oxidative stress, this phenomenon occurs when there is a lack of balance between the production of harmful reactive oxygen species and the body's ability to cleanse the produced peroxides and free oxygen radicals can contribute to the damage of cells, cancer formation and diseases associated with dementia, such as Parkinson's or Alzheimer's disease. This does not mean that free radicals are completely unnecessary- they can be helpful in the fight against pathogens, but it is about maintaining their appropriate proportions. This is the antioxidant barrier of the body where the enzyme called Total Superoxide Dismutase (T-SOD) plays a very important role. T-SOD assessed the work of this barrier as little in the context of forest therapy, discovered that the forest bath reduces inflammatory reactions and reduces oxidative stress, antioxidant mechanisms work more efficiently.

Stress plays an important role in the immune process. The cortisol is produced by the adrenal glands. Intensive production of this substance has a detrimental effect on organisms, disrupts in a number of processes and weakens the body's defence reactions. Unfortunately, in modern life, cortisol is often produced in excess, and the constant pressure and haste cause that we do not rest, and we are in a state of constant agitation. In the event of acute sudden stress, the level of adrenaline in the blood rises, too. The research, where the influence of the forest on stress, and thus indirectly also on the immunity system, was conducted on one group of participants. It was examined whether being in the forest atmosphere is effective while walking slowly, paying attention to the environment around them. The second group in the next part of the experiment were engaged in the same activities, but they were asked to spend time in the city centre. Both experiments were carried out in accordance with some key rules: participants could not talk to each other, had their phones turned off, and during walks, they moved slowly without effort.  As it turns out, after 15 minutes of walking in the forest, the level of cortisol of participants significantly decreased both in saliva and in blood. This has given the evidence that we can regenerate in the forest quickly after various types of situations that are stressful to us everyday, for example, in a traffic jam. Also, some excessive duties at work generate a lot of stress and, as a result, present as a mental burden.Therefore, regular, even short (15 mins) trips to the forest allow us to get rid of the constant stress for a moment, ‘slow down this machine’.  We can take a break, slow down, regenerate and gain strength. Therefore, the practice of forest bathing is especially useful when we work in stressful conditions. 

Jung’s team decided to examine the female employees of the consulting and health services sector working under a lot of pressure.  It turned out that those who had more frequent contact with nature were generally less stressed, which showed a lower level of cortisol. Forest bathing participants recovered faster,and the forest therapy turned out to be effective in alleviating the effects of psychosocial stress- less exposure to stress and more frequent exposure to nature, makes us healthier and stronger.

Finally, it is worth mentioning that the forest affects the work of the nervous system from an early age. According to research, the benefits on children from being in nature are revolunatory. Research proves that the green remedy has a protective effect and even affects how the brain develops in childhood. This very important stage is key when it comes to shaping what we will be able to cope with in life as adults. It has been noted that children who do not have contact with nature, at a later age are more susceptible to attention deficit disorders and depression.  Thanks to being in nature, they develop cognitively much faster and are more creative. They easily learn how to play in a team, and learning is not so tiring for them. It also turns out that the brains of children growing up in green areas develop differently, the vegetation environment affects the volume of the prefrontal cortex, our most human part of the brain. These areas are also those that are responsible for more efficient memory and less inattention. To conclude, frequent contact with nature shapes our sensitivity and empathy. For that reason, numerous observations from a young age remain with us forever. 

To sum up, I would recommend forest therapy to anyone who would like to improve their health.  This is a very simple practice that benefits your mental and physical health. Forest therapy is based on connection with trees, which can be facilitated by the guide. Forest baths are an important reference to the healing bond between nature.