Does forest bathing actually do anything?

Does forest bathing actually do anything

Forest bathing, the Japanese practice of shinrin-yoku, has real and repeatedly measured short-term effects on stress, mood and a handful of physiological markers. Two separate systematic reviews, pulling together dozens of studies, found consistent drops in blood pressure, stress hormones and reported anxiety after time spent slowly and deliberately in a forest. What the evidence doesn't yet support is the stronger version of the claim circulating in wellness content: that forests have some unique, scientifically settled healing power that ordinary green space or quiet outdoor time can't match.

The term itself dates to 1982, when Japan's forestry agency coined shinrin-yoku to describe slow, unhurried, sensory immersion in a forest, explicitly not hiking, running or exercising. That distinction matters for reading the research: most studies aren't testing exercise in nature, they're testing calm, phone-free presence in it.

What the reviews actually found

A 2019 systematic review published in Environmental Health and Preventive Medicine examined 28 studies, 17 of them randomized controlled trials, covering outcomes from blood pressure and heart rate variability to cortisol, immune markers and self-reported mood. The authors concluded plainly that "forest bathing activities may significantly improve people's physical and psychological health," and found notable reductions in measured anxiety and depression across the pooled studies. Using a standard quality checklist, they rated 16 of the 28 papers as high quality and 12 as low quality, with randomized trials scoring meaningfully better than non-randomized ones.

A separate, broader 2017 state-of-the-art review in the International Journal of Environmental Research and Public Health covered 64 studies and reported some of the more specific physiological findings behind the trend. Natural killer cell activity, a measure tied to immune function, rose after a forest trip and in one study stayed elevated for more than seven days. Forest exposure was linked to lower inflammation markers in patients with hypertension and COPD, and to improved cardiac function in people with coronary artery disease after a supervised park walk. In one cited depression study, 61% of a forest-program group reached remission, compared with 21% of a hospital-program group and just 5% of controls, a striking gap, though from a single study rather than a replicated finding.

The limits that matter

Both reviews are candid about where the evidence runs thin. Sample sizes in the underlying studies were frequently small, often 12 to 24 people, and many studies drew only on healthy young adults or university students, which limits how far the results generalize to, say, an older adult with chronic illness or someone outside Asia. Geography is itself a limitation: in the 2019 review, 13 of the 28 studies came from Japan, 6 from China, 5 from South Korea and 3 from Taiwan, with just one from Poland and none from the Americas. Most sessions were also short, with 71% of the reviewed trials lasting only one to three days, which says little about whether benefits persist or compound with regular practice.

There's also a harder question the research mostly skips: is this about forests specifically, or about slowing down, disconnecting and being outside in general? Few of the studies compared a forest directly against another calm green space, like a park or a garden, rather than against a busy urban street. One smaller 2022 study that did test this found a virtual-reality forest produced stress and mood improvements similar to a real one, which hints that at least part of the effect may be about attention and relaxation rather than anything forest-specific, like phytoncide compounds given off by trees, a mechanism often cited in popular coverage but still thinly tested.

The 2017 review frames this with a few older psychological theories rather than one single forest-specific mechanism: Rachel and Stephen Kaplan's attention restoration theory, which holds that natural settings let overtaxed, directed attention recover; Roger Ulrich's stress reduction theory, which proposes humans have an evolved, largely automatic calming response to certain natural scenes; and the biophilia hypothesis from Edward Wilson and Stephen Kellert, which argues humans have an innate affiliation with living systems. None of these three frameworks is specific to forests over other green, relatively untouched natural settings, which again points toward "being calmly outside in nature" as the likelier active ingredient rather than something unique to trees.

Our take

Forest bathing is a legitimate, evidence-backed way to lower stress for an afternoon, with two independent reviews behind the core effects on blood pressure, cortisol and mood. It is not a proven immune treatment or a substitute for medical care, and the research base is still small, short and geographically narrow. If the nearest real forest is far away, the honest reading of this evidence is that slow, unhurried, phone-free time in whatever decent green space you can reach will likely get you most of the same benefit. For other nature-adjacent wellness habits worth the same scrutiny, we've also checked whether cold plunges live up to the hype and whether grounding or earthing sheets do anything measurable.

This is general information, not medical advice. Talk to a clinician before changing anything, especially if you are pregnant, nursing, or managing a condition.