Shinrin-yoku, also known as a "forest bath," originated in Japan and it's believed to enhance one’s well-being while helping “connect” with nature. It involves immersing oneself in a forest or natural environment and mindfully engaging with the surroundings through the senses. Western medicine offers “nature prescriptions” – the walk with or without the mindfulness. Does it improve our health?
Let’s begin with a quick definition, a nature prescription is a recommendation to a patient to “spend a fixed amount of time a week in a natural setting, such as a park.” It is most frequently an adjunctive treatment, perhaps like “you need to lose a bit of weight” or “make better diet choices.” And while its advocates point to benefits like a greater social connectedness or appreciation of the environment, are there any actual clinical benefits? The authors of this study in Lancet’s Planetary Health used meta-analysis seeking outcomes for “systolic blood pressure, diastolic blood pressure, depression, anxiety, step counts, and time spent on physical activities.”
They identified 92 studies, many (72%) randomized control studies, most frequently in high-income countries and across a range of participant ages. Cardiovascular and psychiatric co-morbidities were noted in about 14% of the studies. The settings for the “back-to-nature” prescriptions included forests and nature reserves, community, home and botanical gardens, and parks. Only two studies considered beaches. The prescriptive activities included walking (46%), gardening (29%), meditation, and breath exercises (29%). Of the studies,
- 67% reported psychological or cognitive benefits – a “moderate” improvement in depression scores and a “moderate to large effect” on anxiety scores.
- 42% reported physical health benefits – roughly 4mm Hg reduction in systolic and diastolic blood pressures. A study in obese children showed improvement in these pressures in those classified as high or “borderline” when the study was initiated. Whether the walking was in the woods or the city, blood pressure was improved.
- 25% reported behavioral benefits – including increased step counts and minutes of “moderate” physical activity. For school students and cancer survivors, nature vs. playground, and outdoor vs. indoor, made no difference in the improvements.
- 22% reported biomarkers of stress, inflammation, and cardiovascular fitness
The researchers noted that these nature prescriptions utilized a diverse range of natural settings and a range of activities suited to the patient's health conditions—many combined physical activities, such as walking, with relaxation, such as meditation.
“Our review concludes that the present evidence indicates nature prescriptions can provide positive benefits on blood pressure, symptoms of depression and anxiety, and physical activity.”
It is difficult to separate the increase in activity from the environment in which it occurs. There are studies showing that walking on a treadmill will also improve your cognitive and physical parameters. From a clinician’s perspective, any environment fostering and encouraging increased physicality is worthwhile. The physicians that know their patients can recommend an environment that supports those efforts; for some, walking the urban environment is uplifting; for others, trees, open air, or beaches mark the special place. That said, if one allows a more mentally “porous” relationship with our environment, many will find that “The Force” is strong in natural surroundings.
Source: Effect of nature prescriptions on cardiometabolic and mental health, and physical activity: a systematic review Lancet Planetary Health DOI: 10.1016/S2542-5196(23)00025-6
