Nature Exposure / Green Prescribing
Nature Exposure and Green Prescribing
Evidence grade varies by use. See the breakdown on the entry. Read how the Atlas grades evidence.
The strongest synthesis is Nguyen and colleagues' 2023 systematic review in The Lancet Planetary Health, which the authors report screened 92 unique studies and pooled 28 in meta-analyses. The authors reported a mean systolic blood pressure reduction of about 4.8 mmHg, a moderate-to-large effect on depression scores (standardised mean difference roughly -0.5), an effect on anxiety scores, and higher daily step counts. Those are findings attributed to that review, and the authors flag substantial heterogeneity, generally short follow-up, small samples, varied "prescription" definitions, and difficulty isolating nature from co-delivered physical activity and social contact. This supports an honest grade 3: emerging human data with some randomized trials, not the multiple-RCT, guideline-endorsed footing of grade 4 or grade 5. Program evaluations (for example UK Green Social Prescribing pilots that report wellbeing gains across roughly 8,000 participants) describe service-level benefit but are uncontrolled.
Reference only. Not medical advice.
| Treatment | Grade | Notes |
|---|---|---|
| Blood pressure / cardiometabolic | 3 of 5 | 2023 meta-analysis reported about -4.8 mmHg systolic; modest, heterogeneous, short follow-up |
| Depression symptoms | 3 of 5 | Moderate-to-large pooled effect (SMD about -0.5) reported, but small samples and confounding by co-delivered activity |
| Anxiety symptoms | 3 of 5 | Significant pooled reduction reported; wide confidence intervals and high heterogeneity |
| Physical activity / step count | 3 of 5 | Higher daily steps reported; overlaps with exercise prescribing, hard to attribute to nature alone |
| Immune function (NK cell activity) | 2 of 5 | Repeatedly reported by one Japanese group in small cohorts; limited independent replication |
What can go wrong
Risk is low for most people: outdoor time is broadly safe and self-limiting. Practical cautions include sun exposure, ticks and insect-borne illness, heat, allergens, terrain and fall risk, and access inequity, since safe green and blue space is not equally available across neighborhoods. Nature exposure is an adjunct, not a substitute, for indicated care of moderate-to-severe depression, anxiety, or cardiovascular disease, which should be managed by a qualified clinician.
This is something to take to a clinician. The Atlas can tell you what is known about nature exposure / green prescribing in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Green prescribing is the formal practice of a health professional referring a patient to time in nature, parks, gardens, woodlands, or blue space such as rivers and coast, sometimes as a written prescription. It is broader than forest bathing, which is one Japanese expression of the same idea. Proponents describe consistent short-term effects on blood pressure, mood, anxiety, and physical activity, and several national programs (New Zealand's Green Prescription, Canada's PaRx, the UK's Green Social Prescribing network) have built referral pathways into routine care. The honest evidentiary picture is encouraging but unsettled: human trials exist and meta-analysis reports benefit, yet effect sizes are heterogeneous, follow-up is short, and the active ingredient is hard to isolate from the exercise and social contact that nature prescriptions bundle in. Enel treats green prescribing as a low-risk, plausibly beneficial environmental intervention whose population-health value may exceed what any single mechanism can yet explain.
A clinician writes "spend time in nature" on a pad, and a growing body of human studies suggests the dose may do something, even if no one can fully separate the trees from the walking and company that come with them.
How it is supposed to work
Mechanisms are proposed rather than settled. Researchers describe candidate pathways including reduced sympathetic arousal and lower stress-hormone levels, increased physical activity, restored directed attention, exposure to daylight, and possible immune effects. Proponents such as forest-medicine groups report increased natural killer cell activity after forest trips. Reviewers stress that nature prescriptions bundle exercise, daylight, and social contact, so the specific contribution attributable to nature alone is not yet isolated.
What people get wrong
Often saidForest bathing is an ancient Zen or samurai-era tradition.
ActuallyThe term shinrin-yoku was coined in 1982 by Japan's Forestry Agency as a public-health and forest-conservation campaign, though it draws on far older land-relationship traditions.
Often saidStudies prove that nature itself, not the walking or company, is doing the healing.
ActuallyTrials report benefit, but most nature prescriptions bundle exercise, daylight, and social contact, and reviewers note the specific contribution of 'nature' is not yet isolated.
Who profits, and who pushes back
Phi-Yen Nguyen and colleagues
Nature prescriptions showed effects on blood pressure, depression, and anxiety, but the evidence carries substantial heterogeneity and the effective components remain to be disentangled.
Melissa Lem
Sells this. Has a commercial interest in a product sold as this compound, as of July 2026.
We describe nature as a low-cost, low-risk prescription, and thousands of clinicians have now registered to write it.
Qing Li
Our studies report increased natural killer cell activity and lowered stress hormones after forest trips, an effect we did not see on a comparable city trip.
Indigenous land-health scholars
Connection to Country is reciprocal and place-specific; reducing it to a prescribable nature dose risks stripping the relationship that gives it meaning.
Where the research comes from
Most of the published research on this comes from one place. 85% of it is from Japan. Findings that no unrelated group has reproduced are weaker than the study count makes them look.
| Place | Share of published research |
|---|---|
| Japan | 85% |
| United Kingdom | 80% |
| New Zealand / Australia | 75% |
| Canada | 70% |
| United States | 55% |
How we got here
Structured relationships between human health and land are oldest in Indigenous traditions. Aboriginal and Torres Strait Islander peoples of Australia describe health as inseparable from caring for and being on Country, a framing they document across tens of thousands of years of continuous practice, and many Indigenous peoples of the Americas, the Pacific, and named African regions hold comparable land-as-medicine cosmologies. The most direct modern ancestor of clinical nature prescribing is Japanese, where the Forestry Agency under director Tomohide Akiyama coined shinrin-yoku (forest bathing) in 1982 as a public-health and forest-conservation campaign, later building a network of certified Forest Therapy bases with state-funded physiological research from roughly 2004 to 2006. New Zealand's Green Prescription, a written primary-care prescription introduced in the 1990s, formalized the idea of a clinician prescribing physical activity and outdoor time. The United Kingdom, Canada, and parts of Australia and Scandinavia have since layered nature referral onto social-prescribing infrastructure. Western academic framing through biophilia and attention-restoration theory arrived late and should not be mistaken for the origin.
Health-and-land traditions are oldest among Indigenous peoples. Aboriginal and Torres Strait Islander peoples of Australia describe wellbeing as inseparable from connection to Country, and Indigenous peoples of the Americas, the Pacific, and named African regions hold comparable land-as-medicine frameworks documented across very long timescales. The clinical, prescribable form is far younger: Japan's Forestry Agency coined shinrin-yoku in 1982 as a public-health and forest-conservation campaign and later certified Forest Therapy bases with government-evaluated physiological research. New Zealand introduced the written Green Prescription in the 1990s, Canada's BC Parks Foundation launched PaRx in 2020, and the United Kingdom embedded nature referral within NHS social prescribing, with a cross-government Green Social Prescribing program evaluated nationally. Western theories of biophilia and attention restoration entered the story late and describe rather than originate the practice.
- Pre-contactIndigenous peoples (Aboriginal Australian, Americas, Pacific, named African regions) practice land-based, relational models of health
- 1982Japan's Forestry Agency director Tomohide Akiyama coins shinrin-yoku (forest bathing)
- 1990sNew Zealand introduces the Green Prescription, a written clinician prescription for activity and outdoor time
- Nov 2020PaRx, Canada's first national nature-prescription program, launches via the BC Parks Foundation
- 2023-2024Lancet Planetary Health meta-analysis reports pooling of 28 studies; UK Green Social Prescribing pilots report a 2024 national evaluation
How it is understood
Indigenous Australian and other land-health traditions are living frameworks whose relational meaning is easily lost when reduced to a prescribable nature dose.
Where scholars disagree
Green prescribing is not itself a regulated ceremony, but its lineage and history rest on living Indigenous frameworks, especially Aboriginal and Torres Strait Islander connection to Country and comparable land-as-medicine traditions of the Americas, the Pacific, and named African regions. Commercializing or repackaging these relational frameworks into a generic prescribable nature dose raises active sovereignty questions, including who holds the knowledge, who benefits, and whether place-specific reciprocal meaning is credited rather than extracted. The flag is on so that Indigenous custodianship is named, not flattened.
Whether observed benefits come from nature itself or from the exercise, daylight, and social contact bundled into nature prescriptions is contested. The clinical finding (people referred to nature tend to improve on blood pressure, mood, and activity) is treated separately from the mechanistic claim that nature is the active ingredient.
Forest-medicine proponents (e.g. Qing Li and colleagues, Nippon Medical School)
Nature exposure has specific physiological effects, such as increased natural killer cell activity and lowered stress hormones, that they report were not seen on comparable urban trips.
What it rests onRepeated small-cohort studies from a Japanese research group reporting immune and stress-hormone changes after forest visits.
Systematic reviewers (e.g. Nguyen and colleagues, 2023 Lancet Planetary Health)
Benefits are real at the program level but the specific contribution of nature cannot yet be isolated from co-delivered physical activity, daylight, and social contact.
What it rests onMeta-analysis reporting high heterogeneity, short follow-up, varied prescription definitions, and bundled co-interventions across the trial base.
This disagreement is live. It has not settled.
At a glance
- Oldest documented origin
- Indigenous land-health traditions (e.g. Aboriginal Australian 'Country'); clinical form coined in Japan as shinrin-yoku, 1982
- Best current evidence
- Nguyen et al. 2023, Lancet Planetary Health, as reported by the authors: 92 studies screened, 28 meta-analyzed; SBP about -4.8 mmHg, depression SMD about -0.5
- Typical 'dose'
- Programs such as PaRx recommend roughly two hours per week in nature, in sessions of at least 20 minutes
- Scope
- Broader than forest bathing: includes parks, gardens, woodlands, and blue space (rivers, lakes, coast)
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Nature Exposure / Green Prescribing. A short entry is not a safe entry.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- What people take it for. We have not catalogued the claims made for it.
Sources
No sources recorded for this entry yet. Nothing on this page can be checked against a citation until that changes, so treat it as a summary awaiting its evidence.