Forest Bathing Relieves Stress, Fights Cancer, Strengthens Immunity

A steel catwalk 150 feet in the air stretches out across the treetops near Sacha Lodge in the rain forest of Equador Courtesy of Sacha Lodge

“Forest bathing” has become a popular leisure activity, and is also a field of study for medical doctors. In Japan, there is the “Japanese Society of Forest Medicine” and “Forest Therapy Society” dedicated to promoting the medical applications of forests and advocating the various health benefits of forest bathing.

Scientists have discovered that when people are close to the forest, their mood becomes relaxed, their stress reduced, their blood pressure and heart rate will be lowered, and more importantly, their immunity will be strengthened. Therefore, regular forest bathing not only prevents diseases, but also has the effect of healing them.

There have been many stories of healing related to immersion in nature.

Gravely Ill Tuberculosis Patient Cured After Moving Into a Forest

“I Lived in the Woods,” a best-selling book in the 1950s, recounted one case in which a cosmopolitan woman dying from tuberculosis moved into a cabin in a pine forest in Maine, to live the life she wanted before her passing.

So she spent one winter in the woods doing what made her happy every day.

In the following spring, she found that her breathing had become normal and all her discomforts had subsided.

She found this to be very strange, so she visited several doctors and a local hospital and did various physical examinations. The new diagnosis was that her tuberculosis had disappeared.

Tumor Disappears After Patient’s Month-Long Hiking Trip

According to Discover magazine, John Matzke had a melanoma in his armpit and underwent several surgeries to remove the tumor. Later, the cancer spread to his lungs, and doctors advised him to get immediate treatment, or he would pass away within a few months. However, Matzke decided to take a month off to get stronger before returning for the treatment.

Matzke then went for a hike in the mountains. He paid attention to healthy eating and meditated. And he often imagined that he had powerful white blood cells in his body to destroy the cancer cells. A month later, he returned to the hospital to prepare for treatment, and the doctors surprisingly discovered that the cancerous lesions that had been so large had already disappeared without a trace.

After Matzke returned from his hike, a white halo appeared around his melanoma. Doctors determined that it was a sign that the immune system was attacking the cancer cells. This means that while Matzke was recuperating, something suddenly triggered his immune system to remove the tumor from his lungs.

The Healing Powers of Forest Bathing

In both cases, the individuals’ self-healing might have been triggered by factors other than the forest, such as mood changes, dietary changes, meditation and/or mindfulness (thoughts), all of which may strengthen the immune system and thus produce health benefits. There are also many studies, which have proven that simply being in the forest can relieve physical and mental stress, enhance the body’s immune functions, and strengthen its ability to fight cancer and infections.

The following are several of the research findings by the scientists:

Strengthening Immunity, Fighting Cancer and Infections

Japanese forest medicine authority Qing Li published a research study in 2007 in the International Journal of Immunopathology and Pharmacology. In the study, his team took 12 urban men and asked them to spend three days and two nights in three different forests, during which time they each walked for a total of six hours.

At the end of the trip, the natural killer cells in the subjects’ blood increased in activity by around 50 percent. Natural killer cells are immune cells that specialize in destroying various types of cancer cells and infected cells. In addition, all three major anti-cancer proteins of natural killer cells increased in number, and these effects lasted for more than seven days after the forest bath.

In a follow-up study, Qing Li detected phytoncides, including α-pinenes and β-pinenes, in the forest air.

Phytoncide is a volatile organic compound released by plants for self-preservation, and is anti-insect and anti-bacterial. Qing Li confirmed that inhalation of these phytoncides can increase the activity of natural killer cells and the amount of anti-cancer proteins even in an urban indoor environment. Phytoncides are an important factor in the immune boosting effect of forest bathing.

A 2017 South Korean study in the journal Toxicology Research also pointed out that terpenes, the main component of phytoncide, are toxic to cancer cells and harmless to healthy cells. In the article, the anti-tumor, anti-inflammatory and neuron-protective potential of various terpenes in forests was discussed in detail.

Reducing Stress Hormones

Stress accumulated in urban life can also be relieved in the forest. Qing Li’s research team then brought in 13 women to repeat the forest tour experiment. However, in addition, they also collected their urine samples. The results showed that after the forest bathing, the concentration of stress hormones, such as adrenaline and norepinephrine, in the subjects’ urine samples decreased. Of course, this experiment also reaffirmed the previous results that the natural killer cell activity and the amount of anti-cancer proteins in the blood of these women also increased.

To verify that forest bathing’s health benefits were due to the forest environment rather than the effects of exercise, Qing Li conducted another control experiment. In this study, the subjects took a trip to the forest and a trip to a city without trees. Both trips lasted three days and two nights, and their lifestyle and activities were the same, except for the different environments. The city tour did not produce the same effect as the forest tour, and the city air did not contain phytoncides, such as α-pinenes and β-pinenes.

Regulating the Autonomic Nervous System

A 2010 study published in the journal Environmental Health and Preventive Medicine discovered that walking in the forest or just sitting in the forest and watching the lush nature can help lower cortisol, blood pressure, heart rate, and sympathetic nerve activity; and increase parasympathetic nerve activity, to achieve the effect of regulating the autonomic nervous system. It can also reduce fatigue and improve mood. Meanwhile, walking in the city or sitting and watching the city has no such healing effect. In this study, the researchers recruited a total of 280 subjects to do experiments in 24 Japanese forests, and all received consistent results.

Another study found that even looking at trees from a distance or photos of natural scenery can heal the body and relieve physical and mental stress.

A study by Dr. Roger Ulrich, a renowned medical architect, was published in the journal Science in 1984. This study pointed out that patients with lush trees outside their windows had shorter recovery times than those with only brick walls outside, and they used less painkillers and had fewer postoperative complications than the latter group.

A 2010 study published in the Health Environments Research & Design Journal showed that looking at pictures of verdant landscapes, streams, or flowers for just a few minutes relaxed physiological parameters, such as muscle tension, electrocardiogram, and blood pressure, and also reduced pain, anger, and anxiety.

How to Reap the Benefits of Forest Bathing—It’s Simple

Just by walking into a forest, you are already bathing in the forest. Qing Li pointed out that forest bathing is not a sport or a walk, but a way to feel the forest with your five senses and to connect with nature.

First of all, you should put away your cell phone and camera, and then stroll casually, not necessarily with a destination in mind.

Appreciation: Observe the flowers, trees, valleys, and streams, and see the sun rays penetrate through tree leaves and branches.

Listening: Listen to the chirping of birds and insects, the sound of flowing water, and the rustle of swaying leaves and branches.

Smelling: Take a deep breath and enjoy the fresh air of the forest and the fragrance of phytoncides.

Touching: Feel the tree trunks, soak your hands and feet in the stream, or lie down on the grass to rest.

If you can’t go into the forest, you can still walk around in the nearby park, hang a few delightful pictures of the natural landscape in your office and home, and put some natural essential oils in your room. All of these methods can be helpful.