Hansen and colleagues went looking. Starting from a hundred and twenty-seven papers on , forest bathing and nature therapy, sixty-four met their , sorted into physiological effects, psychological effects, and frameworks. Almost all of the research comes from Japan and China. The review supports the health benefits, and then says plainly what the evidence base still lacks.
The gap is in study design rather than in findings. What exists is a large body of short-term work on physiological and psychological measures, conducted in two countries. What the authors call for is , in Western cultures, on clinically therapeutic effects. They also address healthcare workers directly, suggesting the practice as something to use themselves against stress and burnout.
Forest bathing arrives in English-language wellness writing with a lot of confidence and not much citation. Hansen, Jones and Tocchini set out to establish what the empirical research actually shows about the physiological and psychological effects of Shinrin-Yoku, as studied in Japan and China.
The search was systematic. Electronic databases, including PubMed, PubMed Central, CINAHL, PsycINFO and Scopus, plus snowball references, produced a hundred and twenty-seven papers using the terms Shinrin-yoku, forest bathing and nature therapy. The collection was then narrowed to work published between 2007 and 2017, and sixty-four studies met the inclusion criteria.
Those sixty-four divide into four groups: physiological, psychological, sensory metrics and frameworks. That division is itself informative, because it shows a field measuring in several registers at once, from stress hormones to self-reported mood to the specific sensory channels involved, rather than converging on one outcome.
The conclusion is supportive and unfinished. The authors hold that current literature supports comprehensive health benefits from exposure to nature and green environments, and they encourage healthcare professionals to practice it themselves against undue stress and burnout. In the same breath they call for longitudinal research, conducted worldwide, to produce new evidence. Two cautions follow. This is a review and inherits the limits of its sources, and the geographic concentration in Japan and China leaves open how far the findings carry elsewhere.
wat. Sixty-four studies say the forest does something; almost none of them followed anyone for long.
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It separates two questions people tend to merge. Whether time among trees changes physiological measures is reasonably well studied. Whether it works as a clinical treatment over months is largely untested.
How do we know?
A state-of-the-art review searched PubMed, PubMed Central, CINAHL, PsycINFO and Scopus, along with snowball references, narrowing to papers published between 2007 and 2017 that evaluated forest bathing across varied populations and settings.
What is still unknown
A review rather than a trial, so it inherits the weaknesses of what it reviews: short exposures and measures that vary between studies. Its geographic concentration also leaves open how far the findings transfer.
Learn something?
Where to next
Half an hour in a park. Does it really do something to the body’s numbers?stress
What did researchers find in blood samples from perfectly healthy people?health
Which persuades more, numbers or one person’s story?health