Scientists are discovering each day more and more of the benefits of nature for human beings, both physical and psychological. Those benefits include helping with self-esteem, happiness, creativity, relaxation, as well as the production of soothing brain waves that promote a sense of well-being.

The practice of forest bathing, or Shinrin-Yoku in Japanese, is taking in the forest atmosphere through our senses, it is a way to connect back to mother nature. Forest bathing was developed in Japan during the 1980s, and since then a robust body of scientific research came to confirm its benefits.

In fact, a simple mindful walk in the forest would promote relaxation, stress reduction, boost immune functions, and the list goes on. Forests are particularly beneficial, but the slightest element of nature does us good. So let’s discover how this works.

What is Shinrin-Yoku (Forest Baths)?

Shinrin-Yoku is a practice originated from Japan and is becoming very popular in the western world these recent years. Shinrin in Japanese means “forest,” and yoku means “bath.” So shinrin-yoku means bathing in the forest atmosphere.

People suffering from lung diseases would be brought to forests to provide them with healthier air.

Forest bathing consists of immersing yourself in a forest, paying attention only to your senses and the present moment. The general idea of shinrin-yoku is to bring humans closer to nature in order to benefit from its therapeutic properties.

Experts in the subject have even coined the term Sylvotherapy (of silva which means wood/forest in Latin) because of its virtues and its positive physiological effects proven by research.

In a 1995 study, the most important results observed in several subjects who spent 40 minutes in the forest in the morning and afternoon were:

  • Decreased tension

  • Decreased anxiety and fatigue

  • And decreased salivary cortisol

Other studies have supplemented this research and have shown other benefits, including:

  • Decreased blood glucose levels in some diabetics

  • Improved moods

  • Increased immunoglobulin A, G and M levels in the blood

The practice of shinrin-yoku is well known and followed, particularly in Asian countries. But today, especially in big cities, it has become harder to get in contact with nature frequently.

How Human Relationship to Natural Have Changed?

Our relationship with nature has changed a lot in recent centuries and even more so in recent decades. The truth is, our relationship to nature has been ambivalent:

  • On the one hand, it is essential to our survival, ensuring the habitability of the planet through a diversity of ecological and ecosystem processes.

  • But on the other hand, it also refers to our vulnerability. It can represent an area of insecurity, even predation. In the movies, stories set in a dark forest still haunt our imagination.

Historically, humans have grouped themselves at the heart of forests and gradually organized the control of their environment, particularly through agriculture.

But today, forests have regressed and given way to urban areas. Now more than half of the world’s population lives in an urbanized area, and more than three-quarters of Americans live in cities.

In fact, our interactions with nature have changed in several ways:

  • We live mainly in environments designed and built by humans. Also, fields and forests are disappearing from living spaces.

  • Encounters with animal and plant diversity are becoming increasingly rare. Several specialists, such as Robert Pyle, an American ecologist, speak of an “extinction of the natural experience”.

  • Our lifestyles have changed. We move less than before and spend a lot of time in front of screens (almost four hours a day on average) instead of enjoying natural parks and wildlife.

However, studies that highlight the benefits of nature have accumulated in recent decades.

What Are The benefits of Forest Bathing

Forest bathing promotes several health improvements, including:

  • A decrease in stress, measured by a decrease in heart rate, blood pressure and cortisol levels in saliva. (Cortisol is often called the stress hormone)

  • Reduces depression

  • Improves self-esteem

  • Increases feelings of happiness and well-being

  • Contact with nature also promotes cognitive functions (concentration, learning, etc.), reducing fatigue and restoring attention abilities.

As early as the 1990s, Rachel Kaplan of the University of Michigan, USA, had shown that scenes of wilderness (such as the passage of the wind in foliage or a flowing stream of water) attract our attention in a gentle and discreet way, allowing rest and cognitive recovery.

In a 2012 experiment conducted by Ruth Atchley of the University of Kansas and her colleagues, the performance of participants in a creativity test increased by 50% after four days of hiking in major American parks.

Are there also physical benefits to nature?

The benefits of nature are not only psychological, but they are also physical. Several studies have shown that being close to natural environments reduces pain and accelerate the healing of some patients, or prevent certain diseases.

In 2006, Qing Li of the Japanese School of Medicine in Tokyo and his colleagues discovered that phytoncides (essential oils emitted by trees) promote the activity of NK cells, which in humans track and kill cells infected with viruses.

Our brains become more efficient

For thousands of years, our ancestors lived in the wild. It is there that, generation after generation, evolution has worked its way, forging our genes and neural systems.

Even today, our brains would still be adapted to it. A whole series of neuroscience studies show that the performance of our brains is better around natural landscapes, and this leads to a more positive psychological state.

One of the common advantages nature have to offer to our brains is performance optimization: Research suggests that our visual cortex is particularly effective in analyzing natural scenes, and is better able to detect the elementary components of an image depicting a natural environment such as line orientation, contrast, shapes, and so on.

In 2016, Florian Mormann of the University of Bonn, Germany, and his colleagues further showed that some neurons of the human parahippocampal gyrus are specialized in processing outdoor scenes. Since this region is closely connected to the hippocampus (the memory center of the brain), it could help to better memorize places, especially natural ones, when forming a memory.

But the benefits of nature are not limited to perception. In a study conducted in 2015 by Zheng Chen of Tongji University in Shanghai and his colleagues, participants were asked to sit for 20 minutes in an environment that was either man-made or natural, while their brain activity was recorded by electroencephalography.

The researchers then found that the different brain regions interact more when we are surrounded by greenery. According to them, this is a sign that the brain is generally more efficient around nature.

The brain ruminates less in the wild

But performance is not everything. In 2015, Gregory Bratman of Stanford University and his colleagues investigated why a natural environment prevents depression and anxiety disorders.

They showed that 90 minutes of walking in a forest leads to a decrease in the activity of the prefrontal ventromedian cortex, a cerebral zone associated with self-reflection and focusing on oneself, and therefore to negative ruminations, omnipresent in depressive patients.

Through psychological questionnaires, the researchers confirmed that the harmful ruminations decreased after a 90 minutes walk in nature. However, these benefits were not observed after walking in an urban environment.

Part of the explanation would come from the fact that nature provokes a sense of wonder, which diverts our attention from our ruminations. As early as the 1990s, American researchers Stephen and Rachel Kaplan showed how beneficial this “effortless fascination” is.

But what exactly attracts our attention in natural landscapes?

Of course, nature is full of varied and interesting things to experience: The sight of swaying trees, the sound of the wind, the smell of the earth, and so on. This certainly plays a role.

But several studies have shown that another purely visual factor called “fractal dimension” is important. 

Fractals are shapes that show similar patterns at different sizes and scales. For example, a simple straight line (when you zoom in, you always get a line). However, “natural” fractals are rougher, more imprecise, than those present in artificial environments (think of a tree branch). The patterns are not exactly the same at the different scales, and the shapes are generally more irregular, which results mathematically in a higher fractal dimension.

It is this lack of precision that seems to attract the attention of observers. And it would be even greater if nature is preserved.

In 2018, Paul Stevens, from the University of Derby, United Kingdom, showed that the richer the biodiversity of a site, the higher its fractal dimension and the more positive emotions it inspires for those who watch it.

This pleasant psychological state can be detected in the brain. In 2015, Caroline Hägerhäll of the Swedish University of Agricultural Sciences and her colleagues measured the brain activity of participants who were looking at either fractal forms in nature or exact fractals.

The researchers then found that exposure to natural fractals led to the production of alpha waves, characteristic of a state of relaxation. 

And as early as 1981, Roger Ulrich of the University of Delaware showed the presence of these alpha waves when looking at a natural landscape rather than an urban environment.

In this way, nature gently engages our neural systems without overloading them. Our attention is neither violently captured by aggressive noises, nor blocked by negative ruminations. It is the opposite of that; our brain alternates pleasantly between the surrounding world and our own thoughts.

In addition, having adapted to natural environments during evolution, the brain easily analyzes what it perceives, and this fluidity seems to soothe it. On the contrary, the urban environment is a source of stress and negative emotions.

In 2010, thanks to functional magnetic resonance imaging (fMRI), Korean researcher Kwang-Won Kim and his colleagues discovered that the sight of a busy environment such as a high traffic part of a city activates the amygdala, an area associated with anxiety and other unpleasant psychological states. This activation was not observed in the case of scenes of nature.

When asked about their emotional state in the fMRI device, 50% of participants who had observed urban environments reported feeling “choked”, compared to only 4% of those placed in front of natural landscapes. Moreover, more than 90% of the latter had felt “at ease”.

How about the social benefits of nature?

Social benefits have also been observed. Richard Mitchell, from the University of Glasgow, for example, has shown that access to green spaces reduces health inequalities caused by income disparity; it is in a way a “free care for all”.

In addition, natural environments promote calmness, self-control and reduce feelings of frustration and anger. In doing so, they contribute to the development of pro-social behavior and an atmosphere of cooperation.

On the other hand, several studies associate the development of some pathologies (depression, allergies, attention disorders, obesity, etc.) with environments that are too artificial, or with too little contact with the natural environment.

In the hectic context of our essentially urban life, the benefits of trees and plants appear as a necessary counterpoint to the constant mental and social pressure. But which nature to favour? Are there any particularly beneficial environments? And if so, how can this be explained?

Why are forest walks particularly beneficial to us?

Regarding the first question, the award goes to forest walks, which offer a very immersive experience.

In the middle of forests, signs of human activity are rare or even non-existent. Instead, the forest is entirely open to seeing, smelling, hearing, feeling, and touching.

The landscape, the swaying of the foliage, the tree trunks that repeat themselves endlessly, the roughness of the barks, the smell of a forest after the rain, the singing of birds, the rustling of leaves – these elements produce a multi-sensory experience.

How forests benefit us through all of our senses

Smell

Some of the experiences discussed above are linked in particular to substances called phytoncides. This is a generic term that refers to a wide variety of molecules excreted in the air by trees and forests.

The information perceived by the senses is then analyzed by the brain and influences the activity of the areas dedicated to psychological and physical control.

The atmospheric concentration of these phytoncides in a forest depends on many factors, such as seasonality, the weather, as well as the composition of forest vegetation.

Several studies have highlighted the effects of some of these molecules. For example, in 2003, Samantha Dayawansa of Toyama University, Japan, showed that inhaling cedrol (found in the essential oil of confers trees, which are trees that grow needles instead of leaves and cones instead of flowers – see picture below) reduces blood pressure, heart rate, and helps with breathing to be slower and deeper.

conifer plant
A conifer plant

Also, in coniferous forests (consisting mostly of conifers), an antibacterial substance produced by trees called alpha-pinene is shown to promote relaxation.

Sight

Visually, nature is not shy of benefits either: the soft-focus induced by forests facilitates the restoration of cognitive functions and evokes calmness. This was what revealed in a study done by Yoshifumi Miyazaki’s team at Chiba University in Japan in 2018.

participants in this study saw their sense of comfort and relaxation increase after only one and a half minutes of contemplating forest photographs, compared to the control group that had to look at pictures of buildings and urban areas.

Trees and plants are beneficial to us even if they can only be seen from our windows. The view that one has from one’s window onto natural elements or landscapes contributes to a significant increase in residents’ satisfaction with their neighbourhood and their sense of well-being, compared to a view overlooking a man-made structure or even the sky.

Some studies, including that of psychologist Won Soo Shin of Chungbuk National University in South Korea, have even shown that employees who see a forest from their office windows are more satisfied with their work and feel less stress than those who only see urban buildings.

Sound

The sounds of nature, and especially the sounds emitted by birds, would be particularly effective in reducing stress and restoring focus.

In 2010, Jesper Alvarsson and his colleagues at Stockholm University showed through various physiological measurements that people calm down faster after a stressful task when listening to the sounds of nature.

According to the work of Eleanor Ratcliffe’s team at the University of Surrey in Great Britain, some bird songs also increase the sense of well-being and connection to nature.

Touch

Finally, let’s talk about the sense of touch. According to several studies, and this is very interesting and odd at the same time, the simple touch of a tree trunk would do us good. 

In some experiments, researchers have asked volunteers to touch raw or variously coated wood panels. They then found that the raw wood resulted in a beneficial lowering of blood pressure.

Thus, during a walk in the forest, each sense offers particular physiological and psychological benefits. These then add up, resulting in a much more restorative experience than a simple walk in an urban environment.

In the practice of forest walking, it is recommended to turn your attention to the present moment, to enjoy the immersion in full consciousness. This approach is similar to the practice of meditation, with the natural environment acting as the object of focus.

However, the positive effects of nature are not limited to forest areas alone. Other natural environments also have a positive impact on human health and well-being.

How about the practice of Sea Bathing, is it similar to Forest Bathing?

As early as the 18th century, the practice of therapeutic Sea Bathing spread throughout Europe. In the nineteenth century, multiple sanatoriums were built in areas far from pollution, in the mountains or by the sea, to enable patients particularly those suffering from tuberculosis to enjoy the benefits of the open air and the sun.

The creation of many green spaces and urban parks also dates from this period. As a result of a hygienic concern, nature has been perceived as a means of offsetting the pollution and diseases generated by a high human concentration.

Generally, the more natural an environment is (which means, the less visibly modified by humans it is), the more beneficial it is to our health. The same activity provides superior benefits when practiced in a natural environment, rather than an artificial environment. And people who have the most green spaces near their homes are healthier.

The Feeling of Being Part of a Whole With Nature

The human species has evolved in contact with nature, and this contact has forged our preferences.

The biophilia hypothesis, developed by British biologist Edward Wilson in the 1980s, argues that humans have an innate, genetically registered tendency to seek connections with nature and other forms of life.

But as early as the 1950s, researchers like Fred Attneave and Horace Barlow believed that our brains had adapted to the natural environment, where they functioned better. This is what modern neuroscience tends to confirm.

Culturally, our relationship with nature also defines us as humans. Interactions with the natural environment can awaken our senses, create a feeling of being part of a whole, leading to an extension of values to the whole living world,  and inspire a spiritual approach to life, for example, by questioning the meaning of existence.

Unlike contemporary common belief, happiness does not necessarily lie in satisfying hedonistic needs, but perhaps through the search for and construction of a meaningful life, more focused on values such as personal development, social contribution and environmental awareness.

In reality, the preservation of nature and human well-being are two sides of the same ecological sustainability process. Only a change in behavior will help to cope with anthropogenic (human impact on the environment) disruptions.

But for people to accept change, it will be necessary to maintain, or even regain, the link with nature. Rising to this challenge is a societal choice, which must be translated into concrete actions:

On the one hand, we have every interest in multiplying the rich and diverse experiences that nature offers, for our children and for us.

On the other hand, we must preserve existing natural environments but also develop new ones, closer to homes. And thus put nature at the heart of our lives and cities.

How Forests Can Be Used To Heal Us In The Future

The study of what nature experiences bring us is bound to develop strongly.

According to some practitioners, increasing knowledge about the link between nature and the nervous system would make it possible to optimize the benefits by proposing personalized recommendations, which take into account the particularities of each person, the types of environments, and the type of interaction (e.g. camping, hiking, simple forest photography displayed in the living room, etc.).

The “dose of nature” received, which means the duration, the frequency and intensity of exposure, is probably also important.

Imagine that one day you will be given the following prescription: “You will take two hours of forest walking and one-hour sea bathing”. This would certainly involve reorganizing your schedule, but would provide more lasting benefits than a few pills.

Prescriptions will also have to be adapted to age. A study by Jo Barton of the University of Essex in Great Britain showed that outdoor physical activity (such as walking in a park) improves self-esteem more strongly among young people, and has a greater impact on the mood among older people.

The benefits of interacting with nature are also very important for children. This field of study is a particularly developed area of research (click here to read our article about the benefits of nature for children in particular).

In Summary

Forest bathing acts on our body and brain through multiple mechanisms, improving our physical and psychological state. A lot of research is now proving its benefits.

As the mechanisms underlying the improvement of well-being are revealed, we also question the foundations of these benefits; why do we react so strongly to contact with nature?

The simplest explanation is that we are intrinsically beings of nature, in the sense that we are connected to the environment, physically, genetically, and culturally. Research suggests that the stronger the sense of connection, the greater the benefits on health and well-being.

Physically, we are in constant contact with what surrounds us. People must therefore protect their environment as well because their happiness depends on it.

Author

Jim Miller

Jim spent his twenties trying tounderstand how our primitive minds get in the way of self-growth. He has a lot of interesting ideas about human psychology that he doesn't hesitate to share when opportunity presents itself.

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Author

Jim Miller

Jim spent his twenties trying tounderstand how our primitive minds get in the way of self-growth. He has a lot of interesting ideas about human psychology that he doesn't hesitate to share when opportunity presents itself.

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