How do trees

promote wellness?  

It’s the phytoncides.

Phytoncides are the aromatic compounds given off by trees and plants. You’re probably most familiar with them when you notice a whiff of a pine or cedar tree. However, all trees and plants give off phytoncides — whether you notice the scent or not.

A tree’s immune system

Phytoncides are part of a tree’s immune system. These chemicals protect a tree from pests and pathogens and are even used as a way for trees to communicate with one another.

Scientific studies have shown that when we breathe in these compounds, our immune system gets a boost as well.

Trees take in carbon dioxide and give off oxygen. We take in oxygen and give off carbon dioxide. In this way, we literally breathe with trees when we’re outdoors. And, by breathing in trees’ phytoncides in the process, we benefit from their system of immunity.

“Prevention of lifestyle related diseases is a big challenge in the world ... Forest therapy can reduce stress hormones, suggesting that forest therapy may have preventative effects on lifestyle-related diseases.”

— Qing Li, Ph.d., Nippon Medical School in Tokyo, in the “International Handbook of Forest Therapy”

What the science shows

Scientific studies on the effects of spending time in forests have been conducted in Asia, Europe, North America and Australia — all finding similar results. The positive effects on human health can include:

Physiological health:

  • Boost immunity by increasing natural killer cells and anticancer proteins 

  • Reduce stress by lowering cortisol levels

  • Reduce inflammation

  • Lower blood pressure and heart rate

  • Improve sleep

  • Deactivate the sympathetic nervous system (fight or flight)

  • Activate the parasympathetic nervous system (rest and digest) 

  • Regulate blood sugar 

Mental health:  

  • Improve mood by increasing serotonin

  • Reduce anxiety and depression

  • Improve self-esteem  

  • Improve concentration and short-term memory

  • Increase creativity

Spiritual and social health: 

  • Foster understanding of interdependence

  • Increase feeling of social connection and empathy

  • Improve spiritual well-being