Forest Therapy and Shinrin Yoku (森林浴)

Video 1.  Forest Bathing | Shinrin-Yoku | Healing in Nature | Short Documentary (YouTube link)

Forest therapy, a term refer to immersing yourself in the atmosphere of the forest, can be incorporated as a stress-reduction strategy.^[2] The practice began in Japan. Back in the early 1990s the Japanese Ministry of Agriculture, Forestry and Fisheries coined the term Shinrin-yoku — which translates roughly as forest bathing.

The idea that spending time in nature is good for our health is not new. Most of human evolutionary history was spent in environments that lack buildings and walls. Our bodies have adapted to living in the natural world.

Video 2. Trees in the Amazon that make their own rain clouds (YouTube link)

Benefits of Forest Bathing

"Forest bathing could be considered a form of medicine," Philip Barr says, a physician who specializes in integrative medicine at Duke University. "And the benefits of nature can be accessed so simply."

There's a growing body of evidence that the practice can help boost immunity and mood and help reduce stress.

One study published in 2011 compared the effects of walking in the city to taking a forest walk. Both activities required the same amount of physical activity, but researchers found that the forest environment led to more significant reductions in blood pressure and certain stress hormones.

There's another factor that might help explain the decline in blood pressure: Trees release compounds into the forest air that some researchers think could be beneficial for people. Some of the compounds are very distinctive, such as the scent of cedar. 

Back in 2009, Japanese scientists published a small study that found inhaling these tree-derived compounds — known as phytoncides — reduced concentrations of stress hormones in men and women and enhanced the activity of white-blood cells known as natural killer cells .

A study found inhalation of cedar wood oils led to a small reduction in blood pressure. These are preliminary studies, but scientists speculate that the exposure to these tree compounds might enhance the other benefits of the forest.

References

1. Trees Are More than Just Trees: the Good, the Bad, and the Ugly
2. Forest Bathing: A Retreat To Nature Can Boost Immunity And Mood
3. Acute effects of walking in forest environments on cardiovascular and metabolic parameters
4. Autonomic responses during inhalation of natural fragrance of Cedrol in humans
5. Why Forest Therapy Can Be Good for Your Body and Mind
6. The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan
7. Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest)--using salivary cortisol and cerebral activity as indicators
8. Acute effects of walking in forest environments on cardiovascular and metabolic parameters
9. Effect of Natural Compounds on NK Cell Activation
• NK cell-activating compounds: vitamins belonging to classes A, B, C, D, and E, polysaccharides, lectins, and a number of phytochemicals