Most wellness businesses quote the studies that flatter them and quietly skip the caveats. We would rather tell you exactly what is known, what is likely, and what is not proven — and let you decide.
What the research consistently shows
Shinrin-yoku has been studied in Japan since the 1980s, and the physiological findings have been replicated many times. Three results stand out.
Stress hormones fall
The landmark field study measured people in 24 forests across Japan against city environments. Forest settings produced lower cortisol, lower pulse rate, lower blood pressure, greater parasympathetic ("rest and digest") nerve activity and lower sympathetic ("fight or flight") activity.
A later systematic review screened 971 papers, included 22, and meta-analysed 8: salivary cortisol was significantly lower in forest groups than in urban groups.
Park, Tsunetsugu, Kasetani, Kagawa & Miyazaki (2010), Environmental Health and Preventive Medicine; Antonelli et al. (2019), International Journal of Biometeorology
Phytoncides are part of the forest environment
Trees release aromatic compounds known as phytoncides. Their concentration varies with tree species, season and weather, making the air in each forest a distinct sensory environment.
Research continues into how these compounds relate to the wider forest-bathing experience. We describe their presence without treating them as medicine or promising a health outcome.
Mood improves
Measured on the Profile of Mood States scale, forest sessions have been associated with lower scores for anxiety, depression, anger, fatigue and confusion, and higher scores for vigour.
Li Q. (2022), Environmental Health and Preventive Medicine
A surprisingly European idea
Shinrin-yoku is usually presented as something purely Japanese. It is not, quite. Japan's forest therapy system was modelled on Kneipp therapy, developed in nineteenth-century Germany by Sebastian Kneipp, who drew out the body's capacity for recovery through plants, water, terrain and harmony — a response to the pollution and deteriorating cities of the industrial revolution. In Germany today, medical insurance still covers a stay at a health resort.
Japan adapted related European nature-cure traditions to its own forests and developed a distinctive research programme around shinrin-yoku. Both European and Japanese traditions have continued to develop through observation, practice and scientific study.
The rhythm underneath it
Why a forest specifically, rather than any pleasant place? Part of the answer is a phenomenon called 1/f fluctuation — yuragi in Japanese — the rhythm that sits precisely between order and randomness, and which the human nervous system appears deeply attuned to. Dappled light through leaves carries it. So does a mountain stream, and birdsong, and your own heartbeat.
We wrote about this in detail →
See the visual guide to a forest bathing session →
Where we stop
What we will not claim
Forest bathing is not a treatment. The official position, printed on the visitor centre wall at Akasawa where all of this began, is admirably plain: forest bathing and forest therapy do not cure specific diseases. The purpose is to support everyday wellbeing and resilience, not to treat illness. Professor Miyazaki, one of the field's founding researchers, says the same thing — shinrin-yoku is preventive, not a medicinal cure. It is not a substitute for medical care, and we will never suggest otherwise.
Phytoncides are measurable; disease-prevention claims are not established. These aromatic compounds are part of forest air, but their presence does not justify promising that a forest visit will prevent or treat disease.
Expectation plays a part, and the researchers say so. The authors of the largest cortisol meta-analysis noted that anticipated placebo effects may contribute to the results, and called for further research. We think you should know that. It does not make the rest less true — it makes the people reporting it more trustworthy.
So what is actually being offered here?
A few hours in a forest with someone who knows it, moving slowly enough that your body notices. The measured effects on stress physiology are real and replicated. The rest — whether the afternoon matters to you, whether you leave feeling like yourself again — is not something a study can settle, and we would not pretend otherwise.
Most of our guests are not looking for a medical intervention. They are looking for the first genuine rest they have had in months. On that, the evidence and our experience agree.
What Aki has been reading
If you want to go deeper, these are the books that shaped how we guide.
Shinrin-Yoku: The Art and Science of Forest Bathing
By the man who turned a cultural practice into a scientific discipline — associate professor at Nippon Medical School and president of Japan's Society of Forest Medicine. Part science, part practical guide, part argument for the future of forests.
The insight we use most: the effect does not require a wilderness. It requires attention, and time.
Shinrin-Yoku: The Japanese Art of Forest Bathing
The more restrained of the two founding voices. Miyazaki, of Chiba University, prefers the term "forest therapy" for the scientific work and is careful about what the data can and cannot support.
His insistence that this is preventive rather than curative is the reason we write our science page the way we do.
Your Guide to Forest Bathing
Less about the physiology, more about the craft of guiding: how to offer an invitation, how to hold a silence so that it feels safe rather than awkward, how to close a session properly.
The line that stayed with us: the forest is the therapist. The guide only opens the door.
The papers, if you want the originals
- Park B.J., Tsunetsugu Y., Kasetani T., Kagawa T., Miyazaki Y. (2010). "The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan." Environmental Health and Preventive Medicine, 15(1), 18–26.
- Antonelli M., Barbieri G., Donelli D. (2019). "Effects of forest bathing (shinrin-yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis." International Journal of Biometeorology.
This page describes a wellbeing practice and does not constitute medical advice. If you have a health condition, speak to your doctor. Written by Akihiro Wada, certified shinrin-yoku facilitator, Hakone.