The living environment of modern people is significantly different compared to the ancient times. According to the World Health Organization, modern Europeans spend approximately 90% of their time indoors. Meanwhile the UK government media regulator Ofcom says people spend more than 8 hours per day on media devices. Besides, more than half of the world’s population now lives in cities.
Since the environment we live in shapes our brain and affects our health, we can ask how this modern environment is affecting us. Constant stress experienced by modern people seems to be the result of this modern environment, including so called “technostress” – the inability to cope with technologies in a healthy manner. Not surprising, poor mental health is one of the biggest public-health problems in Western nations, including depression, anxiety and mood disorders.
Many studies have been carried out to evaluate the various ways to treat these mental health problems. Amongst them is the effect of the natural environment on human beings, which has been actively studied since the 1980s. The natural environment including plants, wilderness, landscapes and animals.
Since the ancient times, human beings have been communicating with the natural environment. However, the amount of available green space now compared to the past, has drastically reduced, and not without consequences. A growing body of literature shows that expose to natural landscapes or their features, such as plants and animals, has beneficial effects on various health outcomes, such as well-being, physical and mental health, mood and recovery from illness.
Evolutionairy theories suggest that humans are drawn to sounds such as bird songs and breaking waves, and to sights such as colourful leaves of plants and trees as a result of natural selection. Such experiences could have signalled the prescence of preys and the opportunity for shelter, tranquility, comfort, and recovery from stress across human evolution.
Currently, we can achieve these same comforting experiences by viewing natural landscapes during a walk, viewing from a window, or – to a lesser extend – looking at a picture or a video.
Evolutionary theories give us an idea as to why natural environments have a positive effect on humans, but current research explores how the underlying physiological responses are established. How might natural environments promote health? To date, studies have revealed an abundance of possible mechanisms, which are summarized below.
Many plants give off phytoncides – antimicrobial volatile organic compounds – which reduce blood pressure and boost immune functioning. The air in forested and mountainous areas, and near moving water, contains high concentrations of negative air ions, which reduce depression. These environments also contain mycobacterium vaccae, a microorganism that appears to boost immune functioning. Similarly, environmental biodiversity has been proposed to play a key role in immune function by affecting the microorganisms living on the skin and in the gut, although the evidence for this is mixed.
The sights and sounds of nature also reduce sympathetic nervous activity (also known as the ‘fight or flight’ part) and increase parasympathetic activity (the ‘rest and recover’ part). This accounts for the relaxing effects of nature experience, which in turn improves sleep, and counters stress.
Implementing Nature In Daily Life
The medically proven effects of nature on our health are now being used as health-promoting methods in the face of stressful environments. This so called “nature therapy” is defined as “practices aimed at preventing disease through exposure to natural stimuli, providing physiological relaxation and boosting the immune system”.
So, what does that practically mean? Nature therapy could be a walk in the forest or in an urban green space. Visiting such outdoor green spaces for 30 minutes (or more) during the course of a week could already reduce feelings of depression and high blood pressure. Besides outdoor nature, integrating the natural world into indoor spaces also effectively benefits our health. Plants in the workplace increase employee well-being, psychological comfort, job satisfaction, physical health and comfort, creativity, and productivity. Besides, plants improve air quality by filtering the air, reducing indoor air pollution. Photos of natural scenery and the use of esential oils have also been suggested to reduce stress.
Fitzgerald, C. J. & Danner, K. M. Evolution in the Office: How Evolutionary Psychology Can Increase Employee Health, Happiness, and Productivity. Evol. Psychol. 10, 147470491201000 (2012)
Frumkin, H. Beyond toxicity: Human health and the natural environment. Am. J. Prev. Med. 20, 234–240 (2001).
Kuo, M. How might contact with nature promote human health? Promising mechanisms and a possible central pathway. Front. Psychol. 6, 1093 (2015)
Lederbogen, F. et al. City living and urban upbringing affect neural social stress processing in humans. Nature 474, 498–501 (2011)
Lee, M., Lee, J., Park, B.-J. & Miyazaki, Y. Interaction with indoor plants may reduce psychological and physiological stress by suppressing autonomic nervous system activity in young adults: a randomized crossover study. J. Physiol. Anthropol. 34, 21 (2015)
Makin, S. Searching for digital technology’s effects on well-being. Nature 563, S138–S140 (2018)
Tost, H., Champagne, F. A. & Meyer-Lindenberg, A. Environmental influence in the brain, human welfare and mental health. Nat. Neurosci. 18, 1421–31 (2015)
Shanahan, D. F. et al. Health Benefits from Nature Experiences Depend on Dose. Sci. Rep. 6, 28551 (2016)
Spiers, J. G., Chen, H.-J. C., Sernia, C. & Lavidis, N. A. A Combination of Plant-Derived Odors Reduces Corticosterone and Oxidative Indicators of Stress. Chem. Senses 39, 563–569 (2014)
Velarde, M. D., Fry, G. & Tveit, M. Health effects of viewing landscapes – Landscape types in environmental psychology. Urban For. Urban Green. 6, 199–212 (2007)
World Health Organization. Combined or multiple exposure to health stressors in indoor built environments. (2013). Available at: http://www.euro.who.int/__data/assets/pdf_file/0020/248600/Combined-or-multiple-exposure-to-health-stressors-in-indoor-built-environments.pdf