Abstract:
After hearing author Richard Louv speak at the American Academy of Pediatrics Annual Conference and Exhibition in 2010, and meeting countless researchers, advocates, and park professionals from around the world, I became aware of the preponderance of scientific studies (more than 500) that show a convincing correlation between time spent in nature and improved physical and mental health outcomes.
As a pediatrician In Washington, D.C., for the past 18 years, I have provided primary care to thousands of children and personally witnessed the toll taken by chronic disease. The U.S. Centers for Disease Control and Prevention reports there are 70 million Americans diagnosed with hypertension, 29 million with diabetes, 10 million with serious mental illness, and 90 million with obesity. Twenty years ago, I would never have imagined such an immense burden of chronic disease in children and their adult counterparts. This prevalence of chronic disease has reached epidemic proportions as our exposure to natural areas in our environment has plummeted.
After hearing author Richard Louv speak at the American Academy of Pediatrics Annual Conference and Exhibition in 2010, and meeting countless researchers, advocates, and park professionals from around the world, I became aware of the preponderance of scientific studies (more than 500) that show a convincing correlation between time spent in nature and improved physical and mental health outcomes.
A systematic review published in 2018 correlated time spent in nature-rich environments with a decrease in the following conditions: salivary cortisol, heart rate, diastolic blood pressure, cholesterol, risk of preterm birth, Type II diabetes, small size for gestational age, cardiovascular mortality, stroke, hypertension, dyslipidemia, asthma, coronary heart disease, and all-cause mortality.(1) In another systematic review, time in nature positively correlated with improvements in psychological well-being, psychosocial function, psychophysiological stress response, cognitive performance, and social skills and relationships.(2)
Spending time in nature is also linked with decreased anxiety, rumination, and negative affect.(3) Forest environments are shown to decrease cortisol levels, blood pressure, and sympathetic nervous system activity.(4) Access to parks reduces the risk of obesity(5), and living in a neighborhood with more opportunities for physical activity is associated with lower risks of Type 2 diabetes.(6) Some of the earliest studies from Japan showed that forest bathing (shinrin-yoku) increases natural killer cells, which are linked to reducing cancer risk.(7) Living near green spaces reduces overall mortality, even when adjusted for sociodemographic factors.(8)
The science linking nature and human health is promoted by park management and related fields such as landscape architecture, city planning, environmental activism/stewardship, etc., rather than by medicine/public health. For example, although the concept of a park prescription originated in Australia, the concept quickly spread to countries around the world, including to the United States, where the U.S. National Park Service developed the Healthy Parks Healthy People (HPHP) initiative.
Like me, most doctors were unaware of the extensive research that links “spending time in nature” to improved health outcomes. About 10 years ago, I began to educate my colleagues in the health profession about this under-recognized science and have spent the last decade building relationships with both the parks management and health professions to promote two agendas: human health and environmental stewardship.
Connecting my patients to nature has a two-pronged effect: improved human health outcomes and a renewed connection to nature. The former is of interest to doctors and the latter to the parks world. Conscientious visitors need to visit parks and protected areas and form meaningful relationships with nature. This mature relationship between humans and natural areas informs the way humans interact with and value nature. An engaged public will be more likely to exert the political pressure to protect and, in some cases, create more natural spaces. This brings us full circle to park prescription as a powerful tool to promote human health and protect our environment.
Park Prescription
A park prescription literally is a prescription to spend time in a nature-rich setting, most commonly a park. The term “park prescription” is often used synonymously with “nature prescription.”
Naturally, as a physician preoccupied with how better to help my patients prevent and treat chronic disease, I became intrigued with prescribing nature. For the past several years, I have worked diligently to give structure to the concept of “park prescription” and to standardize the nature prescription in the office setting.
In 2017, I founded Park Rx America (PRA), a nonprofit organization whose mission is to educate health professionals about the benefits of prescribing nature and to provide a “no-cost” electronic platform through which registered health professionals can easily prescribe nature to their patients. Every PRA nature prescription specifies place, activity, dose, and frequency. Reminders to patients to fill their nature prescriptions are delivered via text or email. PRA’s platform provides an easy, pain-free way to document the park prescription in the medical record.
By prescribing nature using our platform, clinicians can take advantage of the added clinical value of specificity, electronic reminders, and a patient/client-centered commitment to take the first step to redirect their trajectory of illness into one of health.
Perhaps the best way to illustrate how a doctor prescribes nature using our platform is through a real-life example. Ruth is a 15-year-old female whom I’ve known since she was born. I know both her parents, her maternal grandmother, and her two younger siblings. When she came to me for her well visit, I noticed she was stressed and asked her if there was something she wanted to share with me.
She told me that while her father was abroad visiting her grandmother, he was badly injured and unable to return home. She clearly wanted to see her dad and grandmother but knew that was not likely to happen any time soon. She was comfortable talking with me, but I wondered if she might benefit from a visit with our social worker. She said she wasn’t ready for that step yet; she also denied any suicidal thoughts or intentions.
I knew I wasn’t going to find a way (in the next five minutes) to reunite father and daughter, but I did want to address her stress, anxiety, and feelings of helplessness. To get an idea of her coping skills, I asked her how she managed stress, and she answered that she had a quiet place. I asked if that quiet place happened to be outdoors. As she described the park grounds at the National Zoo, I asked her if she felt safe and comfortable there, then commented on the science behind nature’s role in stress reduction.
When I asked her to share more details of this quiet place, she replied that she likes to sit under a particular tree. I was amazed how one question about “a quiet place” brought her to describe a specific tree.
Dr. Zarr: How often do you do this?
Ruth: Not often enough.
Dr. Zarr: How about I write you a prescription to sit under this tree at the zoo three times week?
Ruth: I can do that.
Dr. Zarr: For how long?
Ruth: Twenty minutes.
Dr. Zarr: Done! When can you come back to see me for follow-up, to make sure you’re feeling better?
Ruth: A month sounds good.
I asked her if I could send her a text/email reminder three times a week. I instructed her to respond on the text/email every time she filled her script. Between that visit and the next, I could follow how many times she was filling her nature script — her “contract” to fill her “own” script to manage her stress.
As doctors, our job is to ask the right questions and to listen to our patients. Our objective is to motivate our patients to do more of what they enjoy and to encourage and reassure them that being in nature is good for them. Using the science link between wellness and nature as a guide to giving advice convinces me that the results of 500 studies are proof enough.
Because Ruth trusts me and my advice, I was able to legitimize her desire to manage this stress with quiet time outdoors, to amplify her intentions, and turn this script into a contract. With the nudge she needed to do this, Ruth practically “wrote” her own nature script. I was just there to guide the process and make it official.
Start Prescribing
Park Rx America is a nationwide community of 650 healthcare professionals, with at least one nature prescriber in every state. Since January 2019, we have collectively written 2,000 nature prescriptions, and of those, 500 have been filled one or more times! PRA continues to make a concerted effort to train clinicians how to prescribe nature effectively to increase the likelihood of patients’ filling their nature prescriptions.
I am confident that PRA can teach us to help our patients feel a sense of accomplishment about changing their lifestyles and ultimately improving their health. PRA capitalizes on the dynamic relationship between healer and patient and provides a powerful tool to enhance the counseling on chronic disease management. We are more reliably and efficiently re-connecting our patients to the natural world and watching them reap the health benefits.
We at PRA are thrilled to partner with AAPL toward our common goal of encouraging more active time in nature-rich areas. I invite you to register at www.ParkRxAmerica.org so you can start prescribing parks today.
References
Twohig-Bennett C, Jones A. The Health Benefits of the Great Outdoors: A Systematic Review and Meta-Analysis of Greenspace Exposure and Health Outcomes. Environ Res. 2018;166: 628–37.
Mygind L, Kjeldsted E, Hartmeyer RD, Mygind E, Bølling M, Bentsen P. Immersive Nature-Experiences as Health Promotion Interventions for Healthy, Vulnerable, and Sick Populations? A Systematic Review and Appraisal of Controlled Studies. Front Psychol. 2019;10:943.
Bratman GN, Daily GC, Levy BJ, Gross JJ. The Benefits of Nature Experience: Improved Affect and Cognition. Landscape and Urban Planning. 2015;138:41–50.
Park B, Tsunetsuga Y, Kasetani T, Kagawa T, Miyazaki Y. The Physiological Effects of Shinrin-yoku (Taking in the Forest Atmosphere or Forest Bathing): Evidence from Field Experiments in 24 Forests Across Japan. Environ Health Prev Med. 2010;15(1):18–26.
Coombes E, et al. The Relationship of Physical Activity and Overweight to Objectively Measured Green Space Accessibility and Use. Soc Sci Med. 2010;70(6):816–22.
Christine PJ, Auchincloss AH, Bertoni A G, Carnethon MR, Sánchez BN, et al. Longitudinal Associations Between Neighborhood Physical and Social Environments and Incident Type 2 Diabetes Mellitus: The Multi-Ethnic Study of Atherosclerosis (MESA). JAMA Intern Med. 2015;175(8):1311–20.
Li Q. Effect of Forest Bathing Trips on Human Immune Function. Environ Health and Prev Med. 2010;15:9–17.
Villeneuve PJ, Jerrett M, Su JG, Burnett RT, et al. A Cohort Study Relating Urban Green Space with Mortality in Ontario, Canada. Environ Res. 2012;115:51–8.