Forest Bathing: Not Just for Homeless People, Anymore

What have trees ever done for anybody, anyway? Sure they help us build ships, tables, paper and a bunch of other things that make civilization possible, but that stuff all comes from chopping them down. In today’s increasingly ‘green’ culture, you always hear about saving the rainforest and protecting nature in general, but does leaving trees standing actually benefit any person?

The answer is a resounding and irrefutable “Yes.” Quite obviously they help improve the air quality and the recycling of oxygen to help us breathe. As an added plus, they are also quite nice to look at. However, it also turns out that they may be helping beyond what is obvious.

Shinrin-yoku – literally “Forest Bathing” – is a Japanese concept introduced by the nation’s Forest Agency in 1982 as a means to promote healthy and active lifestyles. Though they didn’t have the science to support it at the time, the people behind the initiative felt that there must be some benefit to spending time in nature, because quite frankly it seemed too pleasant not to be good for you.

In recent years Dr. Qing Li – associate professor in the Department of Hygiene and Public Health at Tokyo’s Nippon Medical School – has begun to provide the hard proof to back forest bathing.

Researchers have known for quite a while that time spent in nature helps us to relax. When we watch the waves roll in off the ocean or take in a big, spicy lung-full of mountain air, the pressures of modern life seem to wash away. Psychological research has shown that people who spend time in nature often perform better on mental tasks than those who try to relax in the city. They are also rated higher on measures of basic effectiveness.

Dr. Li’s work has gone one step further and measured actual responses the body makes to kicking back in the woods. Participants in his studies – though some might prefer to call them vacations – have demonstrated reduced stress hormones and improved stability in their heart rate. They were even more reactive to changes in their environment.

This is all well and good, but there is one result from forest bathing research that almost seems too amazing to believe. Dr. Li and his students have observed enhanced immune system activity and greater numbers of cancer-fighting cells in their forest-bound guinea pigs.

That almost seems to go too far. You had me with lower stress and better attention, Dr. Li; but a walk in the woods as cancer treatment? What do you take me for?

Once again, cue Qing Li with hard science to support his claims. Leaving the woods and heading into the lab, Dr. Li has shown that phytoncides, which are chemicals produced and emitted into the air by trees through their wood oils, can induce human “Natural Killer” cell activity. Natural killer cells are far better than they sound. The killing they do is of cancer. It’s like Terminator 2.

This work has been supported by other researchers as well. In a study of cancer-laden lab rats, the subjects living in a care-free phytoncide-rich environment had slower tumor growth and their tumors were 40% smaller compared to their regular lab compatriots. 

A good scientist will never tell you that they have proven something beyond all doubt, but sometimes the evidence speaks for itself. Next time you have a choice between a jog on the treadmill or a run through the forest, you might want to opt for the latter. Not only will you feel less stressed and more effective, but  your cancer might not grow as fast, either.