Evidence of Nature Benefits for Mental Wellness #3

Every individual can cope with the normal stresses of life.

“Stress response is triggered by the physical elements of our surroundings, by unpleasant social interactions, or by a perception of something threatening or fearful. When stressed one’s body releases hormones, such as cortisol, that trigger an inner ‘fight or flight’ response. Frequent stress response can fatigue the immune system, and negatively affect other health responses. Researchers typically describe stress in two ways: acute and chronic stress. Acute stress plays an evolutionary and survival role, occurs less often, and is in response to an alarming or traumatic event (such as loss of a job or death of a loved one). Chronic stress occurs when one experiences an ongoing stressor (such as daily freeway commuting, or work demands), leading to a heightened and nearly constant physiological response. Chronic stress is now more often studied because it is the type of stress most likely experienced by urban dwellers, and is an alarming public health threat. One can reduce or eliminate stressors, avoid situations that are triggers, or develop the mindfulness to cope with challenge. Studies suggest that nearby nature experiences in cities can be a helpful buffer.

• The experience of nature appears to be an antidote to the stress effects of urban living. In a key experiment people who viewed a video of a natural setting, after viewing a visual stressor, displayed faster and more complete physiological recovery than those seeing built environments ^1,2.
• Exposure to nature in the form of trees, grass, and flowers can effectively reduce stress³ particularly if initial stress levels are high^4,5. 
• Physiological measures of stress are restored to desirable, more healthful levels when study participants have either been placed within or view green spaces. Stress indicators include heart rate, muscle tension, systolic and diastolic blood pressure, brain electrical activity, skin conductance (sweating), as well as self-reports of perceived stress (a summary is provided by an article in the Journal of Environmental Psychology)⁶.
• A study found that even short-term visits (of about half an hour) to urban nature environments have positive effects on perceived stress relief compared to built-up environments. In addition to more positive mood, salivary cortisol levels decreased⁶.
• A study of 11,000 adults from Denmark showed that living more than 1 km away from green space (forests, parks, beaches, lakes) were 42 percent more likely to report high stress and had the worst scores on evaluations of general health, vitality, mental health and bodily pain⁷.
• Comparing household medical records and natural amenities, those residents with only 10% green space within about half a mile had a 25% greater risk of depression and a 30% greater risk of anxiety disorders vs. those with the highest degree of green space near the home⁸.
• Studies examined the effects of exposure to nature on positive affect and ability to reflect on a life problem⁹. Participants spent 15 min walking in a natural setting, a built setting, or watching videos of natural and built settings. Exposure to nature was found to increase connectedness to nature, ability to direct attention, positive emotions, and ability to reflect on a life problem. The effects were stronger for actual nature than for virtual nature.
• Research found that experiencing nature had a powerful influence on the rehabilitation potential of people greatly affected by a crisis¹⁰. Individuals who have many experiences of nature were less affected by their crisis than are those who have few such experiences. The rehabilitative effect of nature is tied to its function as an enriched environment. During stays in natural settings an interaction takes place between sensory stimulation, emotions and logical thought—an interaction that leads to a new orientation and new ways of seeing one’s self and one’s resources.
• In a Korean study involving patients with moderate to severe depression, participants were assigned to cognitive-behavioral therapy in either a hospital setting or a forest setting (arboretum), while a third group acted as a control and were treated using standard outpatient care in the community¹¹. Overall depressive symptoms were reduced most significantly in the forest group, and the odds of complete remission were relatively high – 20-30% higher than that typically observed from medication alone. Moreover, the forest therapy group had more pronounced reductions in physiological markers of stress, including lower levels of the stress hormone cortisol and improvements in heart rate variability, a marker of adequate circulatory system response to stress. It appears that the settings where psychotherapy is conducted can actually become part of the therapy.
• Based on decades of research we now have guidelines for supportive outdoor spaces ^12,13. A restorative environment should be visually stimulating; it should include the nuanced complexity and opportunity to access information about one’s surroundings that is experienced in well-designed gardens and parks. An environment that readily supports one’s movements and intentions is also more likely to move your body from a stress state to a relaxed state, thus a lower stress level. A restorative green space should have slower movement in the visual field and smells that one associates with pleasant memories. Notably, when we go to a place that we believe heals us we actually do send the human body on a path towards healing.

For more about the healing power of nature:  Reflect and Restore – Urban Green Space for Mental Wellness

¹ Ulrich, R.S., R.F. Simons, B.D. Losito, E. Fiorito, M.A. Miles, & M. Zelson. 1991. Stress recovery during exposure to natural and urban environments. Journal of Environmental Psychology 11, 3: 201-230.

² Ulrich, R.S., & R. Parsons. 1992. Influences of passive experiences with plants on individual well-being and health. In: D. Relf (ed), The Role of Horticulture in Human Well-Being and Social Development: A National Symposium. Timber Press, Arlington VA, pp. 93-103.

³ Ulrich, R.S. 1986. Human responses to vegetation and landscapes. Landscape and Urban Planning 13: 29-44.

⁴ Ulrich, R.S., & D.L. Addoms. 1981. Psychological and recreational benefits of a residential park. Journal of Leisure Research 13, 1: 43-65.

⁵ Ulrich, R.S., U. Dimberg, & B.L. Driver. 1991. Psychophysiological indicators of leisure benefits. In: B.L. Driver, L.R. Brown, & G.L. Peterson (eds), Benefits of Leisure. Venture Publishing, State College PA, pp. 73-89.

⁶ Tyrväinen, L., A. Ojala, K. Korpela, T. Lanki, Y. Tsunetsugu, and T. Kagawa. 2014. The influence of urban green environments on stress relief measures: A field experiment. Journal of Environmental Psychology 38: 1-9.

⁷ Stigsdotter, U.K., O. Ekholm, J. Schipperijn, M. Toftager, F. Kamper-Jørgensen, & T.B. Randrup. 2010. Health promoting outdoor environments – associations between green space, and health, health-related quality of life and stress based on a Danish national representative survey. Scandinavian Journal of Public Health 38, 4: 411-17.

⁸ Maas, J., R.A. Verheij, S. de Vries, P. Spreeuwenberg, F.G. Schellevis, and P.P. Groenewegen. 2009. Morbidity is related to a green living environment. Journal of Epidemiology and Community Health 63, 12: 967-973.

⁹ Mayer, F.S., C.M.P. Frantz, E. Bruehlman-Senecal & K. Dolliver. 2009. Why is nature beneficial? Environment and Behavior 41, 5: 607-643.

¹⁰ Ottosson, J., & P. Grahn. 2008. The role of natural settings in crisis rehabilitation: How does the level of crisis influence the response to experiences of nature with regard to measures of rehabilitation? Landscape Research 33, 1: 51-70.

¹¹ Kim, W., S.K. Lim, E.J. Chung, & J.M. Woo J.M. 2009. The effect of cognitive behavior therapy-based psychotherapy applied in a forest environment on psychological changes and remission of major depression. Psychiatry Investigation 6: 245-254.

¹² Sternberg, E.M. 2009. Healing Spaces: The Science of Place and Well-being. Belknap Press, Cambridge MA.

¹³ Marcus, C. C., and N.A. Sachs. 2013. Therapeutic Landscapes: An Evidence-Based Approach to Designing Healing Gardens and Restorative Outdoor Spaces. John Wiley & Sons, Hoboken NJ.