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That Science Stuff

Most people find that when they spend time in nature it has some sort of positive effect on their mental state, but what you might not know is there is actually science and research behind this stuff! Before I start on the science a quick reminder about what Forest Bathing or Shinrin-yoku is…

Shinrin-yoku is rooted in Japan and literally translates to ‘take the atmosphere of the forest’ and when we are Forest Bathing this is what we are doing, bathing in things called phytoncides and their natural goodness to boost our own physical immunity and powering up our mental health batteries. As a qualified Nature and Forest Therapy Guide with the ANFT, during a session I aim to help you remember, whether consciously or not, that we are all part of nature and explore our deep-rooted relationship with all other beings and the ‘more than human world’. But, there is many elements behind what makes Nature and Forest Therapy so effective on our physical and mental health…

People forest bathing


Trees keep themselves healthy by showering themselves in their own essential oils called phytoncides (meaning ‘exterminated by the plant’ or in latin – phyton/plant + cide/exterminate). When a tree is attacked by a fungus or other organism, the tree diffuses these phytoncides into the air and they seek out and kill the attacking fungus and bacteria. Phytoncides are not just for trees and can also be found in house plants, fruit and vegetables so you do not need to be outside to benefit! In addition, when we spend time amongst phytoncides our own first line defenders, NK or Natural Killer cells increase significantly, even seven days after we have been exposed. These cells are critical to our immune system, they provide rapid responses to virus infected cells and tumour formations. So bathing in the natural oils of the forest is truly good for our bodies!

Back in the 80’s…

Shinrin-yoku all began in Japan in the 1980’s, when the Japanese were transitioning to a tech-based economy. This meant that a lot of people were spending a considerable time inside and the government noticed a huge spike in cancer and autoimmune diseases. So, they began several research projects to figure out how to combat the epidemic. One project asked a very simple question; what happens when human beings are exposed to forest environments? They discovered the magic of phytoncides and the effects these have on the human body and thought this was rather incredible, that simply going into the forest can be considered a preventative treatment for very serious diseases and so Shinrin-yoku was born.

Fractal Patterns

Repetitive patterns found in nature are known as fractal patterns - we find these aesthetically pleasing and they have been found to be stress reducing in humans. When looking at patterns in nature an easy starting point is a tree - the trunk rises from the earth with branches shooting from the trunk, smaller branches shoot from the larger ones, then small twigs, spindly twigs and so on, this repetitive pattern of branch upon branch, twig upon twig is a fractal pattern; the wooden scales of a simple pine cone, spirally arranged around a central stalk; the spiral of a snail shell; unfurling of a fern or the bloom of a flower – all repetitive patterns in nature that reduce our stress levels.

Green and Blue

Green is a quiet colour, our eyes need to do little to be able to process it, green strikes the eye in such a way no adjustment is required and we therefore find it restful. Being in the centre of the spectrum, it is the colour of balance - a more important concept than many people realise. When the world about us contains plenty of green and may appear ‘lush’, this indicates the presence of water and little danger of famine, so on a primitive level we are reassured by green. Blue is peaceful, calm and gentle, blue has tremendous power to manage stress. It's a very soothing colour that helps calm your mind, slow down your heart rate, lower your blood pressure and reduce anxiety. We of course find blue in the sky above and the water below us.


There has been lots of research as to why water brings on such a calming or pleasing reaction, studies comparing people who live by the sea to those who don’t and the higher stress levels in the latter for example. The exact reasons as to why water is so calming are not completely known, but the fact is that in most people, water lapping nearby, a flowing stream on a warm day or an incoming sea tide helps our shoulders lower and mind relax. Water is a key element to a Forest Therapy session, it can slow down our brainwaves, help us to reach a meditative state, bring out a creative playful side or leave us in awe of its power and beauty.

Additional Reading

Association of Nature and Forest Therapy

Effects of phytoncides from trees on humans NK cells

Fractal Patterns in Nature


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