Step Outside – Why it’s more important than ever to take a daily dose of nature

Research Reviews
Author: Gemma Goldenberg
Date:

The relationship between nature and well-being

This article looks at a range of research evidence which suggests that contact with nature is beneficial for physical and mental health, cognition and learning.

It will consider why nature has this effect, how this is applicable to the current situation given the outbreak of COVID-19 and how adults and children can still access the benefits of nature while observing rules on social distancing, self-isolation or lockdown.

The benefits of nature exposure – what is the evidence?

Nature has long been considered beneficial to humans in many ways and a wide evidence base has documented the positive effects of nature on humans. In children, nature exposure has been linked to a wide range of benefits, including improved wellbeing and self-regulation (McCree, Cutting and Sherwin, 2018 ), better performance in school tests (Sivarajah, Smith and Thomas, 2018; Wu et al., 2014), reduced ADHD symptoms (Faber Taylor and Kuo, 2009; Kuo and Faber Taylor 2004) improved confidence and social skills (Sheldrake, Amos and Reiss, 2019) and better imaginative play and relationships (Dowdell, Gray and Malone, 2011). Access to nature has also been shown to potentially buffer the effects of childhood stress (Wells and Evans, 2003).

In some of these studies, the effect of nature was substantial. In one experiment, children with ADHD who took a 30 minute walk in a park, as opposed to in an urban setting, experienced such significant improvements in their concentration, that the researchers claimed the effect of the nature walk was equal to that gained by taking Ritalin (Faber-Taylor and Kuo, 2009). In another experiment, children were found to focus so much better on their schoolwork following a lesson outdoors in nature, that teachers redirected children’s attention and behaviour around half as often as they did when indoors (Kuo, Browning and Penner, 2018).

For adults, being in a forest environment has been shown to lower blood pressure, heart rate and levels of cortisol (a stress chemical) more than built environments (Park et al., 2010). In one research study, a 90 minute walk in nature was also shown to decrease rumination, a maladaptive pattern of thought linked to depression, and reduce anxiety (Bratman et al., 2015). Brain scanning imagery has shown that when viewing images of urban environments, activity is greater in brain areas associated with anxiety and stress (the amygdala), whereas images of natural environments trigger activity in the anterior cingulate and insula; brain areas used for positive social behaviour (Kim et al., 2010).

A meta-analysis of over 140 studies, involving over 240 million people, linked spending time outdoors in nature with a wide range of health benefits such as reducing the risk of type II diabetes and cardiovascular disease. They were also more likely to report good overall health and increasing sleep duration (Twohig-Bennet and Jones, 2018).

Why does nature have this effect?

Before looking at the potential mechanisms behind nature’s benefits to humankind, it’s important to critically consider the research evidence. Caution must be taken when looking at correlations such as living near natural green spaces and reporting better overall health. Living in a greener area may be indicative of socio-economic status or a range of other factors that may explain better health. Similarly, when studies claim that people who access nature more frequently are happier and healthier, they do not always account for the fact that someone who has the time and capacity to take walks in the forest regularly may have a less stressful life to begin with. A correlation between factors does not mean that one causes the other.

However, this field of research contains many experimental studies that control for these factors and in some cases, are able to evidence causation. The research base is vast and provides a lot of compelling evidence that nature is beneficial in many ways. So why is this the case?

The meta-analysis cited above suggests that people living near green spaces may have more opportunities for physical activity and social interaction, which lead to better physical and mental health. The authors also believe that exposure to the diverse bacteria in natural areas may improve immunity and reduce inflammation (Twohig-Bennet and Jones, 2018).

According to stress reduction theory (SRT) or psycho-evolutionary theory (Ulrich, 1983) humans have an adaptive, positive response to areas with water and vegetation, which evolved as a means for survival. In other words, humans evolved to be most comfortable where they can seek food, water and shelter, and for this reason natural settings reduce feelings of stress.

It is also thought that content from natural environments, such as views of trees, may be processed more efficiently and easily because the brain and senses evolved in natural environments. This idea has been supported by studies which show that processing urban scenes creates more cognitive load than processing natural ones (Valtchanov and Ellard, 2015; Grassini et al., 2019).

According to attention restoration theory (ART) (Kaplan and Kaplan, 1989) nature is beneficial because it allows our attentional capacities to rest and replenish. Nature engages the brain effortlessly, minimising demands on directed attention, and this means that following nature exposure, cognition is improved.

Some people (cf. White and Shah, 2019) believe that because processing and attending to natural environments is less demanding than being in an urban environment, it creates greater capacity for our minds to work through problems, manage feelings and relate well to other people.

Other explanations for nature’s benefits include research that phytoncides (the natural scent of trees) contribute to reducing stress. Certain smells, such as those of cedar and Taiwan cypress, have been found to reduce blood pressure in laboratory experiments (Park et al., 2010). Bacteria found in soil have also been found to activate brain cells to produce more serotonin. Low serotonin is linked to aggression, anxiety and depression, so most anti-depressant medications work by increasing serotonin levels. It’s therefore thought that walking in nature rich areas and inhaling some of these microbes from soil could provide some of the same benefits as anti-depressant drugs (Lowry et al., 2007).

Why are these research findings so important at this time?

In the face of a global crisis, people may be experiencing more stress, anxiety and depression than before. Not being able to access usual hobbies and support networks and having restricted opportunities for social activity may make this even more difficult to manage. Anything that is available to support mental and physical wellbeing at this time is important to take note of, especially if it is backed up by research evidence and is relatively easy to implement.

Furthermore, the majority of children and adults are now working and learning at home. The home environment may be very different from the one usually used for activities requiring focus and concentration and may offer more distractions. As nature is considered to improve attentional capacity, it may help children and adults to increase their productivity as well as the quality of their work.

How can these benefits be achieved whilst observing rules on social distancing, self-isolation or lockdown?

The current guidance in the UK is that people are permitted to go outside once each day for exercise. Given the research evidence, it may be beneficial to take this exercise in a nature-rich area where possible. A walk or jog in a park or forest should yield greater benefits for physical and mental health than one in an urban environment. Aim for environments with fewer man-made features and a greater amount of green open space or tree canopy as these environments have proved most beneficial in research experiments.

For people who cannot access natural environments locally to home, or who cannot engage in exercise, time spent in a garden may provide some of the same benefits. Studies have shown that even sitting passively in natural environments can improve attention, memory and mood (Norwood et al., 2019). Garden visits and caring for plants have also been linked to improved wellbeing, cognitive skills and social relations in elderly people living in long term care (Rappe, 2005). Therefore, if people have access to a garden with natural features, it is worth spending time there each day, whether that time is spent walking, gardening or just sitting down and taking in the environment.

Where garden access is not available, indoor plants have also been effective. One study showed that installing vertical planted walls into a classroom improved children’s performance on a test of attention and executive function (van den Berg et al., 2017). Another showed that people in the workplace were less anxious and nervous when indoor plants were present (Chang and Chen, 2005).  Consider moving plants into the room where you or your children are working or studying to create more of a natural environment.

Window views, particularly of nature have also been shown to have benefits. Window views of green spaces at work have been linked to lower anxiety (Chang and Chen, 2005) and children have been found to perform better in English and maths if they learn in classrooms with more natural daylight from windows (Heschong, 2002).  Consider setting up work and learning spaces close to a window, ideally one which offers a green view, and take short breaks throughout the day to look out of the window.

Some people may live in urban areas without any green views from the windows. In this case, even viewing videos or images of nature can contribute to reducing stress and improving mood and cognition (Berman, Jonides and Kaplan, 2008). Much of the research on nature’s benefits takes place in a laboratory using slideshows of natural environments which have been shown to reduce blood pressure and heart rate (Gladwell et al., 2012). An internet search for ‘nature slideshow’ yields over 140 million results so there is no danger of running out of new images to view.

However you or your children choose to get your daily dose of nature, the natural environment is a valuable resource which we should not forget during these times.

References

Berman MG, Jonides J and Kaplan S (2008) The cognitive benefits of interacting with nature. Psychological Science 19(12): 1207–1212.

Bratman GN, Hamilton JP, Hahn KS et al. (2015) Nature experience reduces rumination and subgenual prefrontal cortex activation. Proceedings of the National Academy of Sciences of the United States of America 112(28): 8567–8572.

Chang CY and Chen PK (2005) Human response to window views and indoor plants in the workplace. HortScience 40(5):1354–1359.

Dowdell K, Gray T and Malone K (2011) Nature and its influence on children’s outdoor play. Journal of Outdoor and Environmental Education 15(2): 24–35.

Faber Taylor A and Kuo FE (2009) Children with attention deficits concentrate better after walk in the park. Journal of Attention Disorders 12(5): 402–409.

Gladwell VF, Brown DK, Barton JL et al. (2012) The effects of views of nature on autonomic control. European Journal of Applied Physiology 112(9): 3379–3386.

Grassini S, Revonsuo A, Castellotti S et al. (2019) Processing of natural scenery is associated with lower attentional and cognitive load compared with urban ones. Journal of Environmental Psychology 62: 1–11.

Heschong L (2002) Day lighting and student performance. ASHRAE Journal 44: 65–67.

Kaplan R and Kaplan S (1989) The Experience of Nature: A Psychological Perspective. Cambridge: CUP Archive.

Kim, GW, Jeong, GW, Kim, TH, Baek, HS, Oh, SK, Kang, HK, Lee, SG, Kim, YS, & Song, JK (2010) Functional neuroanatomy associated with natural and urban scenic views in the human brain: 3.0T functional MR imaging. Korean Journal of Radiology11(5), 507–513.

Kuo FE and Faber Taylor A (2004) A potential natural treatment for attention-deficit/hyperactivity disorder: Evidence from a national study. American Journal of Public Health 94(9): 1580–1586.

Kuo M, Browning MHEM and Penner ML (2018) Do lessons in nature boost subsequent classroom engagement? Refueling students in flight. Frontiers in Psychology 8: 1–15.

Lowry CA, Hollis JH, De Vries A et al. (2007) Identification of an immune-responsive mesolimbocortical serotonergic system: potential role in regulation of emotional behavior. Neuroscience 146(2): 756–772.

McCree M, Cutting R and Sherwin D (2018) The hare and the tortoise go to forest school: Taking the scenic route to academic attainment via emotional wellbeing outdoors. Early Child Development and Care 188(7): 980–996.

Norwood MF, Lakhani A, Fullagar S et al (2019) A narrative and systematic review of the behavioural, cognitive and emotional effects of passive nature exposure on young people: Evidence for prescribing change. Landscape and Urban Planning 189: 71–79.

Park BJ, Tsunetsugu Y, Kasetani T et al. (2010) The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): Evidence from field experiments in 24 forests across Japan. Environmental Health and Preventive Medicine 15(18).

Rappe E (2005) The influence of a green environment and horticultural activities on the subjective well-being of the elderly living in long-term care. University of Helsinki, Department of Applied Biology, Publication 24.

Sheldrake R, Amos R and Reiss MJ (2019) Children and Nature: A research evaluation for The Wildlife Trust. London: UCL Institute of Education.

Sivarajah S, Smith SM and Thomas SC (2018) Tree cover and species composition effects on academic performance of primary school students. PLoS ONE 13(2): 1–11.

Twohig-Bennett C and Jones A (2018) The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes. Environmental Research 166: 628–637.

Ulrich RS (1983) Aesthetic and affective response to natural environment. In: Altman I and Wohlwill JF (eds) Behavior and The Natural Environment. Boston, MA: Springer, pp. 85–125.

Valtchanov D and Ellard CG (2015) Cognitive and affective responses to natural scenes: Effects of low level visual properties on preference, cognitive load and eye-movements. Journal of Environmental Psychology 43: 184–195.

van den Berg AE, Wesselius JE, Maas J et al. (2017) Green walls for a restorative classroom environment: A controlled evaluation study. Environment and Behavior 49(7): 791–813.

Wells NM and Evans GW (2003) Environment and behavior nearby nature, a buffer of life stress among rural children. Environment 35(3): 311–330.

White, H., & Shah, P. (2019). Attention in Urban and Natural Environments. The Yale journal of biology and medicine92(1), 115–120.

Wu C-D, McNeely E, Cedeño-Laurent JG, Pan W-C, Adamkiewicz G, Dominici F, Lung S-CC, Su H-J, Spengler JD (2014) Linking Student Performance in Massachusetts Elementary Schools with the “Greenness” of School Surroundings Using Remote Sensing. PLoS ONE 9(10): e108548.

Further Reading

Louv R (2008) Last Child in the Woods: Saving Our Children From Nature-Deficit Disorder. Algonquin books. Chapel Hill: United States.

Royal Horticultural Society (RHS) (2020) Your Wellbeing Garden: How to Make Your Garden Good For You. London: DK.

Williams F (2017) The Nature Fix: Why Nature Makes Us Happier, Healthier, and More Creative. New York: WW Norton and Company.