Take a forest bath

Science has a way of validating the obvious. Consider how often psychologists are quoted in the news to prove something everyone knows.

In the case of "shinrin-yoku," translated as "forest bathing," it has been established that people can "restore balance and health by immersing themselves in a forest environment and absorbing its atmosphere." Japan's Ministry of Agriculture, Forestry and Fisheries coined the term years ago, and quite a bit of research has been done on the phenomenon.

Before proceeding, I should emphasize that I am not a doctor, nor do I play one on TV or Facebook. This column will not contain any cures for COVID-19, but therapies or preventions for it do appear in research on forest bathing.

I don't usually set out to engage in forest bathing. While harvesting firewood or herbs, planting trees, or raking up dead leaves for composting, I often check on existing plantings. From a chestnut or fig, I find my eyes wandering to trillium or vanilla leaf plants that are spreading from their wild stands.

Examining the extent of the stand, I might see a Pacific waterleaf or cedar seedling that I hadn't noticed before. The parameters of my senses expand as my sense of duty to my limited tasks drains away.

If the sun's arc hasn't clued me in to how much time has passed, a sense of calm exhilaration does. I end up some distance from where I started, carrying tools that are suddenly incongruous with my experience.

I give myself over to this state because it's infinitely preferable to toil and I know it's therapeutic. As work shades into wild, there will be a dwindling boundary between what I have introduced and what the woodland has manifested itself. As I move toward my permaculture objectives, this is a little taste of what perusing tomorrow's woods will be.

Something similar affects the mushroom hunter in an old-growth forest. Once you've got your forest senses on, fungi appear to you. What is that physiological and psychological shift?

Numerous studies have shown that forest bathing reduces stress hormones such as cortisol, lowers blood pressure and reduces the risk of coronary heart disease. Increased intake of oxygen and nonrepetitive physical activity (taking place, as it does, over the varied surfaces of a forest floor) stimulate the lungs and boost immune function.

Inhalation of phytoncides, volatile substances emitted by trees, increases our production of NK, natural killer, cells. NK cells cull struggling cells, such as those developing into tumors or afflicted by viruses, from our bodies. Fragrances from trees can reverse stress-induced immunosuppression and normalize immune function and neuroendocrine levels.

Of course, this is all particularly salutary during a pandemic caused by a respiratory virus. Tree-emitted volatile terpenes like a-pinene, β-pinene, D-limonene, camphor and α-terpineol have been used to treat respiratory inflammation, and administering them through forest bathing may be safer than ingesting or applying them topically.

Botanist and chemist Diana Beresford Kroeger has suggested certain trees with health-promoting aerosol chemistry be planted around hospitals as part of a therapeutic "bioplan." I couldn't find evidence that Douglas fir is helping anyone at Mason General Hospital, but our evergreen mascot appeared in Italian and Chinese studies as the most effective tree for stress relief - and you don't even have to forest bathe to get the effect. Both studies used virtual-reality woodlands.

South Korean researchers found that forest therapy, a practice analogous to forest bathing, lessened depression and anxiety. An international study concurred, adding that sleep disturbance eased and changes in inflammatory biomarkers took place in young adults affected by cancer aged 18-39.

Combing through the literature on forest bathing has given me a case of the wanders. I hope I remember to take a picture for this column during my therapy. Get out there and immerse yourself in our forest clinics - for your health!

■ Alex Féthière has lived on Harstine Island long enough to forget New York City, where he built community gardens and double-dug his suburban sod into a victory garden. He can be reached at [email protected].