Nature and health

Last changed: 02 February 2023

Swedish research

One of the first Swedish researchers to demonstrate the positive health effects of nature was Terry Hartig, professor of environmental psychology at Uppsala University (Hartig et al 1991). He was followed by several others, the most influential for several decades has been Patrik Grahn and the research group around him at SLU in Alnarp. Together with students, they established a rehabilitation garden and came to be at the forefront of research into garden therapy. In many studies, the Alnarp researchers, as well as researchers at Green Rehab in Gothenburg, have shown that stays and well-designed therapeutic activities in a garden contribute to a better recovery in areas such as exhaustion disorders (e.g. Grahn et al 2017, Sahlin et al 2012; 2015, Stigsdotter et al 2011). In Sweden epidemiological studies have also been carried out which show that being close to accessible nature can lead to better health, although the results varied according to age and gender (among others, Hartig et al 2020, van den Bosch et al 2015).

In the field of nature-based health research in Sweden and internationally, it has been difficult to establish the basic principle: that nature has a positive effect on man's ability to recover. Very little of the research has focused on which type of nature environment has the best effect. Experiences and effects differ between urban nature (park or garden), the nature influenced by man (fields, meadows, production and recreation forests) and more or less undisturbed nature. And if so, how? We may also believe that the nature we have grown up with, as well as other previous experiences of nature, reflects how we react to outdoor stays.

What even counts as nature? This can also be important to know.

Theoretical research on nature-based experiences

The way we experience nature is usually described in terms of spontaneous and focused attention, with its basis in Attention Restoration Theory (ART), which is based on Rachel and Stephen Kaplan's research (Kaplan & Kaplan 1989). According to this theory, spontaneous attention helps boost recovery, and what we experience is then described by the term fascination. We are fascinated by nature's visual impressions (these can be beautiful views but also details, such as the uniform patterns known as fractals) and sounds, such as birdsong and wind, the skin's perception of wind, the sun's warmth, etc. The feeling of getting away (from everyday life), compatibility (that nature meets our needs for recovery) and extension (we feel that everything in nature is holistically connected) also plays a part in the effect (Kaplan 1995).

Using ART as the basis, other researchers have then developed another way of describing nature-based experiences: Perceived Restorativeness Scale (PRS), a questionnaire that can be processed statistically. (Hartig et al 1997, Korpela & Hartig 1996). This instrument has since evolved into Perceived Sensory Dimensions (PSD), where the experience of nature is studied and described in more detail using characteristics such as serenity, space, biodiversity, wildness, culture, prospect/protection, common and presence (Stigsdotter & Grahn 2002). These characteristics have later evolved to describe the experience of nature from four opposing pairs: Natural or culturally influenced, peaceful or social, open or protected, cohesive or diverse (Stoltz et al 2021).

Researchers have found that in rehabilitation from stress-related disease, the garden must contain the ART components fascination, getting away, extension and compatibility. The so-called experience dimensions that are important for stress reduction are serenity, space, nature, prospect and protection. It has also been discovered that social silence can be an important ingredient in ensuring the environment has an assistive function in the rehabilitation garden (Palsdottir et al 2018).

In Swedish forest studies, it has been shown that the most important parameters for recovery ere serenity, space (openness) and wildness (naturalness). Translated into forest-related terms, this means that the forest should be old, have high trees and a good distance between the trees (Sonntag Öström et al 2011, 2015, Stoltz et al 2016).

People's experiences in different environments

There are, after all, some studies examining how people in practice react to different types of nature. One example is a study that shows that the greater the diversity, at both species and ecosystem level, in the surrounding nature, the better it is for people's well-being and health (Aerts et al 2018).

Finnish researchers have shown that both park and forest visits yield positive results on cardiovascular functions (pulse rate, blood pressure and heart variability) in women (Lanki et al 2017). Another study in a Polish suburb with forests also showed the positive effect on mental well-being, pulse rate and blood pressure (Janeczko et al 2020). Similar results have also been obtained from Sweden. Here, comparisons were also made between nature and the urban environment which revealed that the park and the forest reduce stress whereas the city does not (Hedblom et al 2019).

A research study carried out in an arboretum showed positive effects for people with mental ill-health, autism, and dependency and behavioural problems who took part in the activity (O’Brien 2018). An important element in feeling better and becoming engaged was establishing a social connection, working to care for the arboretum, participating in creative activities and mindfulness exercises and using the senses in different ways by tasting, looking, feeling, listening and smelling.

A Swedish study showed that patients in a rehabilitation garden chose to walk in different environments depending on how they felt (Tenngart, Ivarsson, Grahn 2012). Anyone who needed to recover, reflect or concentrate took the 'introverted walk' in the protected part of the garden, which is less landscaped and more natural, and therefore requires less attention. Anyone who needed physical activity or sought rich experiences chose the 'extrovert walk' in those parts of the garden that are more laid out. There is more to watch and interact with, which requires more attention.

Well-being and better health

A major study in which researchers looked at the quality of life of inhabitants of 51 European cities showed the more green space was available, the better the quality of life (Giannico et al 2021). The green spaces were particularly important in the urban areas where the inhabitants had lower incomes.

Researchers also found that well-being and a feeling of connection, closeness and belonging are greater in more natural surroundings than in environments that are more managed and built-up (Knez et al 2018).

The researchers most often investigate and describe what we see in nature. But it is probably not only the visual that is important to nature's beneficial effects but also other sensory experiences. Scents, for example. Swedish research shows that scent perceptions from the park and forest reduce stress more than both sound and visual experiences (Hedblom et al 2019). However, the city's sensory input does not reduce stress.

Here it is appropriate to mention mindfulness, or conscious presence, as it is often called in Swedish. Using the sensory input from nature to train the ability for mindfulness and attention to the present is becoming more and more common (the training is otherwise usually done indoors, focusing mainly on the body, breathing, mind and thoughts). For example, when staying outdoors, we can focus our curiosity on, for example, how the bird song sounds or how the sun feels against our skin; then the brain is allowed to rest for a while, which can lower the stress level.

According to research, mindfulness training in nature can contribute to increased awareness, better cognitive function and less chronic stress compared to doing nothing (Lymeus et al 2020). In fact, nature seems to work as well as a venue for mindfulness training as a meditation room. The researchers also point out that nature can be an environment that facilitates the conscious presence of those who have difficulty concentrating on other mindfulness training.

Natural-based interventions in care and rehabilitation

When describing the effects of nature on well-being and health, it is often a question of how nature stays affect healthy people. Nature-based interventions or 'therapies' are about therapeutic treatments intended to cure or improve a health condition (often stress-related). In the latter case, the rehabilitation gardens at SLU Alnarp and Green Rehab in Gothenburg have been pioneers (see for example Stigsdotter et al 2011 and Sahlin et al 2012). Both the enterprises have worked with multimodal treatment in the nature and garden environment. (Multimodal treatment means there is a team made up of doctors, psychologists, physiotherapists and occupational therapists working together to rehabilitate patients).

Most of the participants who underwent rehabilitation at SLU Alnarp returned to work after one year (Grahn et al 2017). The longer the rehabilitation period (8–24 weeks), the higher the proportion of people who became available for work. The rehabilitation outcomes at Green Rehab in Gothenburg indicate that it reduces burn-out, depression and anxiety and increases well-being. In addition, this type of rehabilitation works well in terms of restarting a stalled rehabilitation process (Sahlin et al 2015).

People who have fled to Sweden to escape war and persecution have also been welcomed to Alnarp's rehabilitation garden. According to research relating to this, the stays there were able to act as a break from everyday problems and stress and help engender a temporary feeling of peace and security. However, this could at the same time be perceived as paradoxical, when the rest of life was filled with uncertainty and the feeling of "being stuck in a rut" in everyday life (Ekstam et al 2021).

Research shows that patients who have participated in nature-based therapy for at least five weeks, afterwards described a feeling that they have become more self-aware and taken ownership of their problems (Dybvik et al 2018). They felt that nature was of existential importance and that the green environment acted as a symbolic tool in the therapy, whilst at the same time helped build new relationships with other participants.

Nature-based rehabilitation in north-west Iceland has also found that open nature, such as coastal areas, forests and parks, in particular in rural areas, has restorative and health-promoting properties (Kristjánsdóttir et al 2020). It was interesting to note that external conditions, such as weather, rarely proved to be an obstacle to treatment.

Nature sounds were described by patients in a nature-based rehabilitation as part of a pleasant and “quiet” experience that contributed to spontaneous attention and fascination (Cerwén et al 2016). Nature scents can also evoke associations and contribute to feelings and physical reactions in people undergoing this type of treatment (Palsdottir et al 2021). The scent of geranium, in particular, played a role in reducing stress and facilitating mental recovery. According to the scientists, scent became a catalyst for sensory consciousness and memory.

Research methodology

Many research articles on nature and health have been published, especially in recent years. Whilst it is true that almost every one reveals positive outcomes, it is important to understand how the research studies are structured. There has been a plethora of review studies (summaries of research studies evaluated by independent researchers) in the field of nature and health, and the same studies are repeated in review article after review article. One might think that reading a few review articles is enough to get a handle on the research area, but it’s not quite that simple. Unfortunately, there are disagreements: for example, many of the review studies do not take into account the fact that nature can be described in many different ways, which means that independent researchers who use too few keywords do not find all the articles in the databases. This leads to them sometimes basing their reasoning on erroneous data (Hartig et al 2014). The review studies are also often based on only one scientific field, such as psychology, although studies also exist that focus on epidemiology, medicine, environmental psychology, forest science, landscape architecture and more.

Another problem is that some of the review articles highlight the benefits of nature without a thorough analysis of the quality of the research studies involved Although today, both physical and mental parameters are usually measured, the evidence is often not convincing as most experimental studies have few study participants and are rarely randomised. This is sometimes pointed out in otherwise relatively positive review studies of nature-based interventions. (Moeller et al 2018, Annerstedt & Währborg 2011). But when even established researchers, such as Ming Kuo in 2015, present summaries blending the high and the low - small studies with larger studies, some which are wholly unambiguous and have good supporting evidence and some which are more questionable, it is all too easy for the layman to believe that all of these have the same probative value.

The best thing would be for more randomised studies to be carried out; unfortunately, it is difficult and expensive to carry out large, randomised studies, and even if these do happen, often only relatively short-term conclusions about improved recovery can be drawn. It is not possible to determine from the same study how long the effect lasts and how nature's beneficial effects contribute to a long-term improved quality of life, well-being and possibly a longer life. This is achieved by carrying out epidemiological studies. This fills some of the gaps in knowledge (but in these, the nature environment itself is a very nebulous concept).

/Text: Ann Dolling


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