can trees help you heal?
Have you heard of forest bathing?
Forest bathing was a term coined by the Japanese government in 1982 from the word “shinrin-yoku,” which means, “taking in the forest atmosphere.” As you might have guessed, forest bathing therapy is simply taking a walk in the woods. Before the rise of the pharmaceutical era, it was common to prescribe unwell people a trip to the woodsy resorts of the Adirondacks or the Swiss Alps in order to connect with nature. Forest bathing was highlighted in a recent wellness trend reports, yet today many consider the therapy good to relieve stress rather than helpful in treating their conditions. Could improvement in well-being be that simple as taking a walk in the forest?
Let’s look at the research
It was interesting to discover that the Japanese government has been leading the way in research funding in this area. From 2004-2013, they spent 4 million into funding forest therapy studies to supplement research being performed by researchers in South Korea, Taiwan and Finland. Today, there are well over 100 studies that measure the health impact of forest bathing in the PubMed research database. In studies that compared forest bathing to city walks, the studies showed that forest bathing significantly lowers blood pressure, heart rate, cortisol levels and sympathetic nerve activity. In other studies, forest bathing showed improvements in depression, anxiety, anger, and stress and significantly increases vigor.
Researchers concluded that the benefit of walking in the woods is due to effect of the phytoncides (essential oils) from the trees on human immune functions. There are several studies measuring human natural killer (NK) activity in NK cells in the presence of these essential oils from the different types of trees. These NK cells are reported to kill tumors or virus-infected cells by releasing anti-cancer proteins. Since forest bathing trips have demonstrated an increase NK activity and the intracellular level of anti-cancer proteins, according the researchers, these findings suggest that forest bathing trips may have a preventive effect on cancer generation and development.
Exploratory research has expanded to cardiovascular disease. In a recent study, patients with congestive heart failure showed a steady decline in the brain natriuretic peptide levels, a biomarker of heart failure, and attenuated inflammatory response after a 4-day forest bathing trip.
Research in this forest bathing continues but that hasn’t stopped that National Health Service in Shetland (Scotland) to last year urge doctors to issue “nature prescriptions” to treat mental illness, diabetes, heart disease, stress and other conditions. They have patient pamphlets that describe the health benefits of being outdoors with activities that can be done throughout the year.
If you are interested in learning more about the research, Dr Qing Li has been a researching Forest Bathing for 30 years and recently released the book titled, “Forest Bathing: How Trees Can Help You Find Health and Happiness.” Or you can also do your own PubMed search for forest bathing and discover these experiments for yourself.
What is forest bathing exactly?
Now that you are aware of the health benefits from walking in the forest, how do you do it? Forest bathing is a short, leisurely visit to a forest and is natural aromatherapy [breathing in the phytoncides (wood essential oils)]. Evergreens like pine trees, cedars, spruces and conifers are the larges producers of phytoncides. Dr. Li recommends that once you have found your spot, you walk aimlessly and let your body be your guide by following your nose. He states,
“The key to unlocking the power of the forest is in the five senses. Let nature enter through your ears, eyes, nose, mouth, hands and feet.”
Two-hour trips are recommended but you can experience improvements after 20 minutes. You are not limited to forest excursions, urban settings and botanical gardens are also restorative.
If you can’t get to a forest or outdoors, then try diffusing essential wood oils such as white cypress, hinoki wood, rosemary, cedar wood, eucalyptus and pine. It is suggested that you diffuse the oils in your room while you sleep, but you can also do it in stressful work environments. Vanderbilt University Medical Emergency Room Center undertook an experiment to study the impact of diffusing oils on a stressful work environment. Before the use of essential oils, 41% of staff reported worked related stress very often and only 13% felt equipped to handle these situations. After the oils were diffused in the department only 3% of the staff reported work related stress often and there were 58% of staff that felt equipped to handle stress situations. There was also an increase in perceived energy from 33% to 77%. There are now over 68 hospitals and other institutions using essentials oils in the workplace.
The future of forest medicine
I get excited when I read and research about these complementary and alternative medicines. It is also always great to learn that there are countries taking the lead in bringing this information forward. For example, the South Korean government has spent more than 140 million on a National Forest Therapy Centre and is developing 37 state-run recreational forests and training 500 hundred forest healing instructors (who knew that was a job?). I have already talked about Japan’s investment in this area, they have 62 designated healing forest bases and roads across the country with each have a particular healing feature. In some forest bases, you can be accompanied by a doctor or have your blood pressure checked along the trail. Special “engagement-based” trails in Finland, France, Luxembourg and Sweden exists because of “Health from the Forest” project through a partnership with the Finnish Forest Research Institute. There is an International Society of Nature of Forest Medicine (infom.org) as an additional resource in promoting forest medicine.
In the US, there are several park prescription initiatives. I found a couple of internet resources at parkrx.org with a planned national park RX day on Sunday April 28th and parkrxamerica.org led by the U.S. pioneer in the “prescribing nature,” Dr. Robert Zarr. There are also a number of wellness resort spas that have forest bathing experiences and businesses that are leading forest excursions. There is even a tree hotel in Sweden. Maybe building a tree house isn’t just for kids. I haven’t been one to be a nature walker, but some of the benefits have swayed me otherwise. I am challenging myself to do a 1-hour walk between now and national park RX day.
 Li Q. Effect of forest bathing trips on human immune function. Environ Health Prev Med. 2009;15(1):9-17.