On Forest Bathing and Nature’s Powers

by Brooke Aruffo


        Researcher Amy Molloy writes “Taking time in nature, specifically a wooded area, can have emotional and physical benefits” (p.6).  Shinrin yoku, or forest bathing, first termed by the Japanese, is prescribed to treat depression, insomnia, high blood pressure, immune disorders, and helps speed up recovery after having surgery (Molloy, 6).  In my research I studied how nature gives us its benefits.  Below I include historical evidence relating to Japanese culture specifically, which has used the natural benefits of nature for centuries.  I will be specifically discussing how nature has a physiological, and psychological power over us when time is spent in natural areas away from large populations.  Nature offers more than beauty to please the eyes of mankind.  Nature offers an improvement to our health with potential to lower blood pressure, increase our power to fight cancer, and allow us to live happier, more sustainable lives.
        The ideas I address in detail are nature’s ability to boosts our levels of cancer fighting cells, the rise of obesity causing increased blood pressure and other health issues such as heart disease caused by high blood pressure.   In regards to mental health, I researched how nature helps to increase happiness, and lowers over all stress levels.  Below I discuss and analyze scientific studies that have been conducted in support of these specific topics.  Giving reason to spend time in nature, I will also discuss how time spent in nature can can be incorporated into daily life, and the challenges many may face doing so.
        The purpose of this paper is to share evidence, and discuss why as humans, we should incorporate more time in nature into our daily lives, as well as spread the word to others.  In the daily life of the average individual living in a cosmopolitan area, there is a lack of availability to nature.  In regards to having a lack of nature, I will discuss the role National forests and protected lands have, and the importance they have to these topics.
        I believe the most notable problems we face with our relationship to nature, is a lack thereof, or a disconnect that many people now have, or are raised with.  The idea of having a relationship to nature is very subjective, and is a case by case matter.  To simplify the concept of  having a relationship with nature, I will define it in regards to this paper as— The time an individual willingly spends surrounded by nature.  It is important for people to understand that having a relationship with nature can be the answer to solving many problems.  The fact that more and more people are beginning to rely on industrialized living in order to adapt to fast paced living is not only pulling people away from the glory of nature but also poisoning us. All in all, in the world of fast paced lifestyles we need to bridge the gap between industrialized living and nature.
         Humans are animals too, and there was a time we lived within nature just like other species.  Scientifically speaking, as animals we adapt to our environments whether it is a success or not.  We all have the same 5 senses, hearing, seeing, smell, taste, and touch.  Thinking about the power of sense of smell, we do not see it as such an asset other than in relation to our use of German shepherds to detect bombs, and drugs.  The human species may not be able to do that, but our sense of smell is still extremely important even if it seems we just use it to smell the flowers, or for cooking.
         Our our ability to intake air allows us to ingest microscopic particles in the air that do have an effect on us.  As stated in The Nature Fix our nasal pathway links directly to our brain.  This being said, anything entering through our nose is fast acting due to the ability of small molecules and gasses to freely pass through the blood brain barrier into brain tissue.  Phytoncides are fumes let off by forest pants, which are able to go through our blood brain barrier into our brains.  The effects of phytoncides have been studied on rats to determine their effectiveness.  Not only did studies show the ability of phytoncides to lower blood pressure, but also to increase the number, and activity of the natural killer cells that fight cancerous cells (Kawakami K, et al.).
         As time progresses there is a rising number of people with health issues caused by the world humanity has created.  Medical specialists are focused on finding cures as well as preventative care.  I believe nature’s potential is not getting fulfilled.  Nature has a great power to impact our health but more often than not, people turn to medications instead of taking the time to be healthful.  Our civilization knows having a healthy diet and exercise can greatly impact our well-being.
        Obviously eating healthier and spending time in nature is not the cure to everything, but it is a start.  There has been a growing rate of depression and high blood pressure in our society and medication is only acting as a band aid, a seemly temporary fix to a much greater and rapidly growing problem.  These problems through more recent decades are beginning to shift from a diagnosis in middle aged adults, to young adults, and now children.  Rob Stein stated during the ongoing National Health and Nutrition Examination Survey between 1988 and 2000 “the average systolic blood pressure increased from 104.6 to 106 and the average diastolic pressure rose from 58.4 to 61.7” in regards to a study conducted about children.  The study discusses how the diagnosis of diabetes, and high blood pressure are rapidly growing in children at younger ages than ever.
         The above study touches on how poor diet has effected this problem, and that it can be treated with better eating habits and exercise.  Something the above study does not mention, is the lack of information being distributed to children, or their families to help aid them in making better choices for their health.  I know from experience that children don’t understand the harsh effects processed foods have.  It is important to distinguish why processed foods are causing this damage, and why spending time exercising is important.  Information like this should be taught and given to families.  Many of these problems root from a lack of education.
        With the rise of destruction and damage to natural lands, I want to share why nature is important.  The evolution of daily life has become much more stressful and fast paced.  Our world has brought rise to many health issues.  There are many companies working to develop inorganic cures for something that has been caused by civilization.  As a human culture we are growing further away from nature, which can easily influence our overall wellbeing.
        Below I will be investigating nature.  It is very important for the success of this paper to develop my own conclusions about why nature is important based on the research I’ve found.  It is also important that the information I provide will influence people to incorporate nature into their lives, even if it is only effecting people I have a direct relationship to.  My goal is to inform, and offer a new perspective on why we should be appreciative of nature, including reasons to protect it, as well as why it should be incorporated into people’s lives.
        Topics I discuss below, are the history of forest medicine in Japanese culture, and an overview of benefits of nature.  The benefits of nature I will be referencing are in regards to our mental state, and the physical condition of our bodies.  I will also discuss a bit of nutrition and how consuming nutrients coming from different plants, fruits, nuts, and seeds affects our body’s mental and physical health.  A majority of my research will be discussion, and analysis of studies supporting my thesis.  The articles I will be referencing discuss nature in its ability to lower blood pressure, help depression, lower stress, and increase immune response in regards to cancer.  
        To create a successful source of knowledge I feel the need to explore environmental issues involving forests, such as forest destruction, as well as the idea of being uneducated about health and nature.  I think as a culture we have become so far removed from experiencing the outdoors, and learning about something that impacts us everyday.  I hope to address problems like climate change, which as humans, we have impacted.  I believe, as a community of beings living on this planet, we need to be more thankful, and respectful to our world in order to live happier and healthier lives.  I personally feel we need to integrate more knowledge about the natural world into our education systems for this to occur.  I believe it is important to educate current and future generations, so we can help to end the destruction of natural areas, as well as incorporate the practice of spending time outside into everyday living as opposed to yearly camping trips, or the occasional hike for some of us.


         To begin I will discuss the roots of my study which had developed a concrete background, and culture that practices spending time in nature.  This is not a study, or test to see the possible benefits, but a lifestyle of another culture which not only looks to nature to increase physical health, but also psychological help.  Japanese culture has practiced what is referred to as ‘shinrin-yoku’ for many years now (Burret, and Simmons).  Shinrin-yoku, synonymous with forest bathing, is the idea of immersing oneself into the forest and taking in the elements of the atmosphere.  Because of the practice of forest bathing, Japanese culture shows its ability to control health problems like blood pressure to mental well being in concerns of stress and depression.
        To my understanding, there is a strong cultural connection to the forest similar to the way some of our culture connects religion with a church.  Japanese culture however, sees a direct relationship between ancient mythology and certain aspects of forest landscaped.  An ancient Japanese religion, ‘Shinto’ has a strong interconnection with the elements of nature.  It is also thought that the elements are recognized as spirits, or ‘Kami’ (Burret, and Simmons).  Kami is a very complex idea to comprehend, and it is stated in Shinto, Nature and Ideology in Contemporary Japan: Making Sacred Forests, by Aike P Rots that observation of Kami can only be experienced intuitively and and cannot be understood conceptually (67).  ‘Kami’, can be understood as the existence of a being (spirit) or physical objects in nature, rocks, trees, soil, ect, and a natural phenomena or occurrence in the forest, the wind blowing, thunder, or water flowing (Rots 66).  Many native peoples believe Kami exists in all aspects of the forest, and are worshiped as an expression of the native faith (Rots 36).
        There are many Shinto shrines, and to explain the space of a Shinto shrine, it can be grasped as almost a cross between a church and a national forest.  The shrine itself sits on a wide spread land of forest, in some cases designed forestry, rebuilt due to of the destruction by man, and in other cases because of natural disasters (Rots, 123). The land is meant for prayer and connection with the Kami.  It is believed by Japanese culture that there are over eight million  Kami within the forests and shrines of Japan.
        One of the most popular forests areas is the Tadasu no Mori, in Kyoto, Japan.  Tadasu no Mori is 12.4 hectares in size.  Although it is undeciphered what the original meaning of the forest name meant, its title loosely translates to ‘forest of correction (or justice)’.  Tadasu no Mori is distinguished with great significance as a land of historical presence and was appointed as a National Historical Site and declared a World Heritage Site by UNESCO.  The Shimogamo-Jinja within the Tadasu no Mori is one of the oldest shinto sanctuaries (Rots, 121).  Although the shrine itself is old in age, the surrounding forest is not.  Many trees in the Tadasu no Mori have been planted, and the grounds are maintained by trained foresters.  The original forest has been previously damaged by natural disasters such as typhoons, and battles during the Onin war during the 15th century (Rots, 123).
         The elements in Japan’s forests which are believed to have powers are the mountains, rivers, waterfalls, and trees.  Based on studies conducted by Nippon Medical School, it is suggested that the experiences an individual has within these elements, that is the combination of the feeling of the sunset, smell of the trees, and sounds of the water, all have abilities to lower stress, promoting better mental health.  The act of emerging oneself within these kinds of environments is almost a form of meditation, focusing on most of our senses by listening, seeing, feeling, and smelling (Burret and Simmons).
        With the use of our five senses, nature can be a very powerful asset to our health. According to Edward O. Wilson who has termed the idea of “Biophilia” believes as human we are born with natural instinct to be attracted to nature.  In the Biophilia Hypothesis it is discussed why as humans we are attracted to nature and have begun to become detached from it, even though it is biologically necessary to our well being.  With this being said, it has become more common for people to move close and closer to cityscapes pulling us away from mother nature. Although we seem to have adapted to these concrete cities, from a physical health standpoint, our bodies have not.  The environment of the city is actually negatively impacting both mental, and physical wellbeing, with a combination of harmful toxins in the air, stressful lifestyles, unhealthy eating, and a lack of nature.  Nature may have the ability to counter balance these negative effects, or at least lessen the symptoms.  Many different studies have provided very compelling conclusions. Some studies with suggestive evidence, for example one study tests rats and their stress response. Other studies which provided concrete evidence tested human subjects over a duration of weeks for example a study by Li, Q, et al, provided a compelling conclusion that forest exposure increases power to fight cancer.


         One fault of studying the effects of nature to obtain concrete answer is that the environmental factors are uncontrolled in every situation.  Uncontrolled variables make it very difficult to conclude a study with proof of forest bathing having benefits. It is discussed in Trends in research related to ‘‘Shinrin-yoku’’ (taking in the forest atmosphere or forest bathing) in Japan, from The Japanese Society for Hygiene in 2009, that in order to conduct a study that will show evidence of benefits from forest bathing, it is needed to be preformed on a national scale.  This study conducted their own controlled version of forrest bathing with the use of modern technology to try reflect the same environments found in Japan’s forests.  One thing the study focused on measuring specifically, was how stress levels were effected by forest bathing.  To measure the physiological benefits of forest bathing, two groups were tested.  One in a lab, and one field study.  For each group both central and autonomic nervous systems were measured, along with biomarkers which indicate stress response.  As the forest environments stimulate ones senses, this triggers sensory responses.  In some cases, these responses are able to reach areas of the brain that effect our emotions and physiological functions.  Different tactics were used to induce the five senses.(Tsunetsugu, Yuko, et al, 30)
        The main goal of the study was looking to prove the benefits of forest bathing, Yuko Tsunetsugu and other writers discusses how forest bathing can have a very calming effect do to its environmental characteristic.  The study states:     
"The reason underlying this feeling of comfort with ‘nature’ or ‘natural matters’ is closely linked with

the human evolutionary process…human physiological functions have had to adapt to the natural   environment through the course of evolution. Consequently, living in  our modern ‘artificial’ society is inherently stressful" (Tsunetsugu, Yuko, et al).

Evolution is something that is scientifically proven, and this study argues it is the reasoning for nature being so beneficial to our out mental health.  Because nature is something that is familiar to our subconscious, it defines a state of familiarity which we as humans find comfort in. I found it very interesting that the study discusses modern society’s environments as ‘artificial’, in which case causes stress among many other issues.
         I also was able to see a parallel in the concept of an ‘artificial’ society within the realm of nutrition, and the way many artificial ingredients in modern day’s processed foods are known to cause health problems.  The cause of food related health issues, is mostly due to the presence of unfamiliar ingredients that are created by man.  When our body does not recognize a substance it usually processes into fat cells, or can cause growth of mutated cells leading to the growth in tumors and cancer.  I realize this is a whole other issue that I can’t quite cover extensively, but I thought it was worth mentioning at this point.
        As pointed out by the study conducted by The Japanese Society for Hygiene in 2009 it was of great importance to be able to prove the benefits of forest bathing by conducting research on a national scale.  After the discussion of their own findings, they discussed previous studies conducted, which also suggests the benefits of forest bathing and sought for a pattern within the results.  “to fully exploit the therapeutic effects of forests by enjoying the benefits of ‘‘Shinrin-yoku’’ on a daily basis, the accumulation of data based on scientific evidence should be continued” says the researchers Tsunetsugu et al.  
        A single study discussed within the above research by Tsunetsugu et al. stood out for revealing the effects of shinrin yoku for the first time.  It was tested on people who walked within the forest for 40 minutes twice per day, and was compared to a walk in a lab, with simulated temperature and humidity to match the factors when the subjects walked in the actual forest.  A POMS (profile of mood state) test was submitted by the subjects before and after the walk in the simulated forest environment, and after the walk within the real forest.  The purpose of this test was to evaluate the subjects psychologically to determine the affect of the forest and the lab tests.  Levels of salivary cortisol concentration was also determined to distinguish the stress response of the subjects.  The result of the study was lowered rates of tension, depression, anger, fatigue, and confusion.  The stress response also showed significant decreases after walking in the forest, and increased after walks in the simulated environments of the lab, proving that even with the advanced technology of today, we are unable to replicate the forest environment close enough to receive any benefits.
        According to the Journal of Wood Science, our sense of smell has been proven to be a powerful source of ingesting Phytoncides.  Phytoncides are natural substances which are let off by forest type trees as defense form to repel certain insects which are considered harmful to them.  After flowing through our nasal passage way, Phytoncides are effective by then passing through the blood brain barrier into our brains.  For humans ingesting these substances directly from the forest air has been proven to increase cancer fighting cells, which will help lower the risk of cancer, counteracting the harmful effects of cancer causing pollutants many interact with daily who live in highly populated areas.  Chamaecyparis Obtusa, or Hinoki Cypress is a tree which is known to emit Phytonocides proven to be effective to our health, both are discusses in a journal from PLOS One (Public Library of Science).  Hinoki Cypress is a species indigenous to Japan’s forests.
         According to the International journal of immunopathology and pharmacology, authors Li, Q, et al. conducted a study on human subjects to identify how Phytoncides effect the production of natural killer cells (NK cells) and effect our stress hormone.  The study took two groups, one who was tested in a city environment, and one who was tested in a forest environment.  Both groups were tested with both blood and urine samples, within a 30 day range testing the levels, and activity of NK cells, and adrenaline, after two hour long walks on the first and second day, a second time after 7 days, and a final time after 30 days.  The controlled group, spent a total of two days in the forest and returned to the city in order to create a consensus of the impact of NK cells after leaving the forest.  The results of the study show that the controlled group who were exposed to the forest for a total of four hours in a two day span showed a noticeable increase of NK cells, as well as a decrease in adrenaline.  The blood tests taken on day 7, 5 days after the walk in within the forest, showed a mild decrease in the number of NK cells but overall was still notably increased.  The group who walked the city streets, showed no changes in their results.  On day 30 the blood and urine samples showed a significant decrease in the NK cells, suggesting the effects lasted well into day 7 but began to decrease gradually until day 30 (Li, Q, et al).
        Because of studies like Li, Q, et al the use of these kinds of essential oils have become popularized to help decrease stress.  In the recent years there has been a craze for the use of essential oils in humidifiers to create different kinds of moods, thesis kinds of oils which aren’t necessarily naturally occurring, are not the same as the oily substance let off by the trees and do not have the same effect as they would normally being present in the forest (Cheng, W. W, et al). This specific benefit of nature has been proven that it cannot be simulated, and can only be obtained by spending time forest bathing.
        A huge problem across America is an increase in high blood pressure.  According to the Centers for Decease Control and Prevention 32% or one third of adults have high blood pressure. High blood pressure puts people at a higher risk of having both heart decease and stroke. As concluded by Current Health Journal, heart disease is the leading cause of death in the United sates with 647,457 deaths tracked in 2017.  Throughout the years the increase of hypertension has gone from seniors, to middle aged, and to young adults, and now the increase in high blood pressure is being seen in children (Stein, Rob).  There is no one factor that has been identified as a cause to this increase, but it had been identified that it is something that can be controlled by something other than medicine.  High blood pressure is another thing that has been studied and proven to show decrease when exposed to nature for periods of time.
        In a study conducted by Kawakami, Kohei, et al. it is shown that blood pressure levels were decreased by the exposure on Phytoncides. Although this study was conducted on test rats, I felt the findings are very compelling in terms of these topics. I also found it convincing in combination of by the research by Li, Q, et al. as it is discussed the stress hormone, adrenaline, is decreased with phytoncide exposure. To track the heart rate of the rats they were placed in tail-cuffs. Blood pressure was measured every hour for 5 hours on two test groups. Overall, the controlled group showed a decreased heart rate. The adrenaline levels showed a decrease of up to 23% within the controlled test subjects (Kawakami, Kohei, et al).  Similar to the study from Li, Q, et al. The subjects stress response, in this case blood pressure, was notably decreased. “Although phytoncides and other volatile compounds can play a role in the overall effects of Shinrin-yoku, watching the forest and contemplating the natural environment seem the most important components capable of significantly influencing cortisol levels” (Antonelli).  Cortisol is a stress hormone that is produced when and individual experiences stress.

          Depression is one common reason for increased cortisol production. Many people in the US, and the rest of the world for the matter struggle from depression. According to the National Survey on Drug Use and Health, 17.3 million adults suffered from depression. Although there are many forms of depression, the most common source of treatment are anti depressant medications, and psychotherapy. Sometimes patients use both therapy, and  prescription drugs, or use choose to use one or the other.  When these two forms of treatment are unable to relieve symptoms, it is common for healthcare providers to use electroconvulsive therapy, also known as shock therapy (Merz).  Electroconvulsive therapy is conducted by sending electric currents to induce a seizure. The treatment is known to be successful in some cases in which medication does not work, but it is not always lasting and many patients turn to a medication on a later date.  Over 70% of people who have previously been treated with Electroconvulsive therapy experience other depression linked symptoms after completion of treatment (Mills).  It has been determine the cortisol levels of an individual forest bathing is significantly reduced, simply by the sight of nature.  Cortisol levels measured from individuals who have forest bathed, or experienced digital computer-generated scenery, also show a decreased levels of cortisol, although the forest bathing group showed a more significant decrease.  In view of the fact that both groups of subjects had decreased levels of cortisol, this suggests that phytoncides, or other factors within a natural environment provide superior capabilities that can only be found in nature.

         All in all, I hope I was able to inform others about the benefits of nature as well as help to persuade people to make more conscious efforts to move forward with these ideas in mind, as well as form their own conclusions about nature.  My argument is that nature has the power to lower blood pressure, increase our power to fight cancer, and allow us to live happier more sustainable lives.  This research will have been a success to myself even if one person changes their opinions about nature.  It is important for me to help make an impact, and make strides towards a better, more sustainable future.  Our world is rapidly growing, just as sicknesses and disease is.  It is important that people understand the impact they have on the environment, as well as the impact the environment has on them.  Sadly the environments we have created for ourselves to survive in have created many health problems.  People living in cityscapes especially, have elevated stress. Many other people suffer from high blood pressure, cancer, and other disease.  Although there are some known causes of illness like cancer, there are so many other variables which are likely the cause to widespread disease within the US.  There are multiple reasons why nature can be beneficial, for example ingesting phytoncides to increase cancer fighting cells.  Additionally, being exposed to nature will assist is people who suffer from high blood pressure.  Finally, incorporating walks within in a forest landscape will decrease cortisol levels, helping to eliminate stress and depression.


Works Cited

Antonelli, Michele, et al. “Effects of Forest Bathing (Shinrin-Yoku) on Levels of Cortisol As a Stress Biomarker: A Systematic Review and Meta-Analysis.” International Journal of Biometeorology, vol. 63, no. 8, 2019, pp. 1117–1134

Burrett, Tina, and Simons, Christopher. “Forest Bathing.” New Internationalist, vol. 491, no. 491, 2016, pp. 18–19.

Bronaugh, Whit. “Forest Therapy.” American Forests, vol. 101, no. 9, 1995, pp. 52–52.  Ebscohost.


CDC, “FastStats - Leading Causes of Death.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 17 Mar. 2017, https://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm.

Cheng, W. W, et al. “Neuropharmacological Activities of Phytoncide Released from Cryptomeria Japonica.” Journal of Wood Science, vol. 55, no. 1, 2009, pp. 27–31. Spriner Link.

Husain, M, et al. “Speed of response and remission in major depressive disorder with acute electroconvulsive therapy (ECT): A Consortium for Research in ECT (CORE) report.”  The Journal of Clinical Psychiatry 65(4): 485–491.

Igarashi, Miho, et al. “Effect of Stimulation by Foliage Plant Display Images on Prefrontal Cortex Activity: A Comparison with Stimulation Using Actual Foliage Plants.” Journal of     Neuroimaging, vol. 25, no. 1, pp. 127–130, 2015. Ebscohost.

Kawakami, Kohei, et al. “Effects of Phytoncides on Blood Pressure Under Restraint Stress in Shrsp.” Clinical & Experimental Pharmacology & Physiology, vol. 31, 2004. Ebscohost.

Kellert, Stephen R, and Edward O Wilson. The Biophilia Hypothesis. Island Press, 1993. Print

Lee, Shin-Hae, et al. “Effects of Essential Oil from Hinoki Cypress, Chamaecyparis Obtusa, on Physiology and Behavior of Flies.” Plos One, vol. 10, no. 12, 2015. Ebscohost.

Li, Q, et al. “Visiting a Forest, but Not a City, Increases Human Natural Killer Activity and  Expression of Anti-Cancer Proteins.” International journal of immunopathology and  pharmacology, volume. 12, issue 1, 2008. Sage Journals.

Mills, Jonathan, and Peter Elwood. “Electroconvulsive Therapy.” Innovait: Education and Inspiration for General Practice, vol. 10, no. 11, 2017. Sage Journals

Molloy, Amy. “Forest Therapy.” The Advertiser, vol. 6, 2015, pp. 6–6. Ebscohost.

Marz, Beverly. “Six Common Depression Types.” Harvard Health, Harvard Health Publishing, 9 June 2018, https://www.health.harvard.edu/mind-and-mood/six-common-depression-types.

NSDUH. “Results from the 2017 National Survey on Drug Use and Health.” SAMHSA, 2017, https://www.samhsa.gov/data/sites/default/files/cbhsq-reports/NSDUHDetailedTabs2017/NSDUHDetailedTabs2017.htm#toc.

Rots, Aike P.“Shinto, Nature and Ideology in Contemporary Japan: Making Sacred Forests.” Bloomsbury Publishing, 2017 . Print.

Stein, Rob. “Rise in Blood Pressure among Children Cited; Study Ties Increase to Obesity Epidemic.” The Washington Post, vol. A.01, 2004, p. 01. ProQuest.

Tsunetsugu, Yuko, et al. “Trends in Research Related to ‘Shinrin-Yoku’ (Taking in the Forest  Atmosphere or Forest Bathing) in Japan.” Environmental Health and Preventive  Medicine, vol. 15, no. 1, 2010, pp. 27–37.

Williams, Florence. The Nature Fix: Why Nature Makes Us Happier, Healthier, and More  Creative. W.W. Norton & Company, 2017. Print.I'm a paragraph. Click here to add your own text and edit me. It's easy.