A Dose of Nature
How much time in nature do we need for a positive effect?
Does the amount of time we spend in nature make a difference to our health and well-being? Is there an optimal ‘dose’?
There is a lot of research that has explored these questions. Here are a few of the findings.
Happiness
People tend to underestimate the increase in happiness they are likely to experience after a ‘short’ walk (17 mins) in ‘unspectacular nature’, and greater time in nature results in a greater increase in happiness[1].
Depression and high blood pressure
Visits to outdoor green spaces of 30 minutes or more during the course of a week result in reduced blood pressure and depression[2].
Health outcomes
There are studies that look at the effects of long-term exposure to nature by correlating green space with where people live. This reflects people who are typically in contact with nature on an everyday ongoing basis. A Japanese study found that people who lived in areas with higher forest coverage had significantly lower mortality (death) rates from cancer than people who lived in less well forested areas[3].
The Harvard School of Public Health reported that 80% of anti-cancer agents have natural origins, and it is widely accepted that the many specific ways nature contributes to improved health outcomes are not all understood[4],[5]. So perhaps the ultimate health and well-being benefit is to live surrounded by nature.
Relaxation
A Japanese study found that 20 minutes viewing an outdoor forest scene resulted in increased relaxation (as measured by brain blood flow)[6].
There are even studies of brain function that show that the human brain prefers scenes of natural environments over those of urban (city) environments even when the images are present for less than a second[7]. We are definitely wired to prefer nature.
Japanese Shinrin Yoku/Forest Bathing
These walks or wanders are typically of 2-3 hours duration, with some becoming all-day ‘retreat’ type experiences in nature. The Nature and Forest Therapy practice developed by the American Association of Forest and Nature Therapy typically involves walks of 2-3 hours duration and we find this gives people time to really be able to slow down and ‘drop in’ to a more relaxed state with the help of our Certified Guides.
So what do we recommend? Really, just that ‘any time in nature is better than no nature’. For tips on ways to connect with nature every day, you can download our free e-book, upon subscription to our newsletter.
In a future post, we’ll explore the question of whether the type of nature makes a difference to the benefits we experience.
Bronwyn Paynter is an occupational therapist, Certified Nature and Forest Therapy Guide and business owner of Flourish nature based OT.
References
[1] Nisbet, E & Zelenski, J 2011, ‘Underestimating nearby nature; Affective forecasting errors obscure the happy path to sustainability’, Psychological Science, vol. 22, pp. 1101-1106.
[2] Shanahan, D, Lin, B, Bush, R, Gaston, K, Dean, J, Barber, E & Fuller, R 2015, ‘Toward improved public health outcomes from urban nature’, American Journal of Public Health, vol. 105, no. 3, pp. 470-477.
[3] Li, Q, Kobayashi, M & Kawada, T 2008, ‘Relationship between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan’, The Open Public Health Journal, vol. 1, pp. 1-7.
[4] Africa, J, Logan, A, Mitchell, R, Korpela, K, Allen, D, Tyrvainen, L, Nisbet, E, Li, Q, Tsunetsugu, Y, Miyazaki, Y, Spengler, J 2014, The Natural Environments Initiative: Illustrative Review and Workshop Statement, NEI Working Group, Center for Health and the Global Environment, Harvard School of Public Health, Boston.
[5] Kuo, M 2015, 'How might contact with nature promote human health? Promising mechanisms and a possible central pathway' Frontiers in Psychology, vol. 6, viewed 3 October 2017 https://www.frontiersin.org/articles/10.3389/fpsyg.2015.01093/full
[6] Tsunetsugu Y, Miyazaki Y 2005, ‘Measurement of absolute hemoglobin concentrations of prefrontal region by nearinfrared time-resolved spectroscopy: examples of experiments and prospects’, Journal of Physiological Anthropology and Applied Human Science, vol. 24, pp. 469–472.
[7] Tinio P, Leder H 2009, ‘Natural scenes are indeed preferred, but image quality might have the last word’, Psychology Aesthetics Creative Arts, vol. 3, pp.52–56.