A return to Shinrin-Yoku
Addressing evidence limitations and accessibility barriers within forest-bathing
Hello. Welcome to Compassionate Nature, the weekly research digest of psychological studies around topics relating to nature connection and compassion. This edition is the second part of a look at Shinrin-Yoku or as it is more well-known, forest-bathing.
“many urban trees owe their existence and survival to our spiritual and instinctive connection to the canopy”
Writing his excellent book Urban Jungle, Ben Wilson discusses the importance of trees within our towns and cities, highlighting an evolved, intuitive relationship we appear to have with them. That deep, often personal, connection featured in this edition last year, which also considered related social and cultural aspects.
Trees within towns and cities can be referred to as the urban forest, which the Forestry Commission research department define as “all the trees in the urban realm – in public and private spaces, along linear routes and waterways and in amenity areas. It contributes to green infrastructure and the wider urban ecosystem. It provides numerous benefits to human society and it does so in vast quantities.”
Some of these health benefits can be maximised by spending time within wooded areas coupled with slow, thoughtful engagement using all of our the senses. This sits at the heart of Shinrin-Yoku or forest-bathing. The psychological benefits, along with some of the physiological ones, featured in this recent post which looked at the overall evidence based using three reviews of related research.
I summarised the research as suggesting “a strong evidence base of forest-bathing as an affordable, accessible opportunity to replenish psychological and emotional states.” There was caution around the quality of some of the related research, primarily due to the use of small, non-generalisable samples, lack of study control protocols such as blinding and results assessed over the short term. This is not to detract from the evidence base, rather to highlight the limitations.
In this second part, I wanted to look at some questions that came to mind while writing that post. Is there an example where some of the research limitations, several of which were described in one of the reviews as challenging to mitigate, been addressed? And just how accessible is forest-bathing for some individuals ?
A lack of control
One of the key limitations highlighted in reviews of forest-bathing research is that it often does not compare forest-bathing with another activity in a controlled study format. A 2024 paper by Dararat Simpattanwong, Qing Li and Kirsten McEwan addressed this by comparing guided forest-bathing with a guided mindful urban walk.
The study was undertaken in Thailand to consider the health benefits that forest-bathing may provide to help address increasing levels of depression and cardiovascular disease in the country. A sample of 30 undergraduate students from Kasetsart University with an average age of 20 years old took part. Two thirds of the participants were female. The research was conducted in December 2023 and involved participants undertaking both a guided forest-bathing walk and a guided mindful urban walk. A group of 15 participants completed the urban walk first while the other 15 participants undertook the forest bathing walk first. Each walk lasted around an hour and involved exercises to support the multi-sensory engagement of the forest and urban environments. The forest-bathing walk was undertaken in an urban forest, with a diversity of trees, wildlife and varied natural landscape features while the urban walk was undertaken in a business area of Bangkok, with high buildings, a few trees, occasional heavy traffic and very little wildlife. The participants emotional state, blood pressure and heart rate variability were taken before and after each walk.
In line with other forest-bathing studies, participants emotional state was found to have benefited from the forest-bathing walk, with increases in vigour and decreases in fatigue, confusion and tension, with the opposite effect observed following the urban walk. However other results were not quite as expected. The authors had expected participants would have lowered heart rate and blood pressure plus increased heart rate variability from the forest-bathing walk in comparison to the urban walk. Indeed participants heart rates did reduce following both walks but with a greater decrease recorded after the urban walk. Additionally systolic blood pressure only reduced in the urban walk condition. There were no significant differences in heart rate variability across the two walks.
What to make of these contradictory findings to most forest-bathing studies? The authors suggest there may have been a compounding ceiling effect upon baseline measurements depending on the order in which participants undertook each walk that may have influenced the effect size of differences. The sample size was too small to detect anything other than large differences.
The study addresses some of the control protocols that the reviews had highlighted as frequent limitations, although it would have been even better if participants had been randomly assigned to the order within which they undertook the two walks. The study does have a few key limitations which often occur in nature related research - participants were predominantly female and the effects are assessed across a short time-period. It also had the key limitation that a lot of psychology studies have in its use of a convenience sample of undergraduate students which reduces the generalisation of results.
The study is reported as the first forest-bathing study to be undertaken in Thailand with the overall results indicating forest-bathing was an engaging activity, with little adverse side-effects and which provided improvements in emotional state. Interestingly the results indicate that whether walking in a forest or an urban setting, taking the time to slow down and notice our surroundings using all of our senses may provide short-term restorative health benefits.
Accessibility
In the previous post on forest-bathing I highlighted the difference between the UK and Japan in terms of forest coverage, with the UK having much less wooded areas, especially of ancient woodland. This presents one access barrier, requiring transport and likely incurring an expense. This becomes even more challenging for individuals with disabilities.
Around a quarter of the UK population has a disability and the British Ecological Society highlight they face a number of additional barriers to accessing nature, from inadequate infrastructure to social exclusion and stigma. For example, a report by Natural England in 2023 considered the accessibility issues for visually impaired people, highlighting there is an increasing prevalence of sight-loss within an ageing population. Natural England also highlighted infrastructure barriers, such as lack of information about sites, poor navigation signage and low levels of accessible facilities.
Given the well-evidenced health benefits that connecting with nature can provide, these barriers preventing a large part of society from experiencing them. Some of the suggestions to address the barriers include increasing multi-sensory opportunities and guided activities, which forest-bathing can provide. However there appears little published peer-reviewed research around forest-bathing and disabilities.
A 2023 qualitative study by Kirsten McEwan and a Canadian research team looked at how forest-bathing could assist individuals with impaired mobility and chronic fatigue. In the paper the limitations and inequalities in accessing nature that many individuals with mobility impairments face are highlighted, which may lead to a sense of exclusion. The research team considered if virtual access to nature in conjunction with guided forest-bathing and an online community could help provide health benefits while helping to address some of the inequality. There is evidence that virtual contact with nature can provide similar benefits, albeit perhaps with reduced effectiveness, as actual contact. Rightly, the authors stress it should not one type of access or the other for individuals with disabilities and the study used a mixture of both in the study.
The online forest-bathing sessions were lead by individuals with disabilities themselves and involved 26 adult participants across Western Canada who all had impaired mobility including as a result of low energy. The mobility impairments of the participants resulted from spinal cord injury, cerebral palsy and multiple sclerosis, with 21 participants requiring the use of a wheelchair. The participants ranged in age from 24 to 80 years old, with an average age of 57, were predominantly of white ethnicity (88%) and the majority (73%) were female.
The forest bathing activities were held over two video conferencing sessions held in groups with each lasting 2.5 hours. The sessions involved a mixture of videos and images taken from a local forest, which not only included images of nature but also first-person perspective videos of people engaging with nature, such as stroking moss or paddling in a stream. The inclusion of these videos was informed by the concept of mirroring - this where the same set of neurons are activated in someone’s brain from the observation of another persons physical action, such as stroking the moss.
Before the sessions participants were invited to collect natural stimuli such as leaves or stones to have with them, as well being able to look outside or where possible go into a garden. It was important that each participant could adapt the sessions to their circumstances. Qualitative analysis was based on three data inputs - surveys completed by participants around the experience of the sessions immediately afterwards and one month later; transcriptions of discussions and chats from the online group sessions; and identification of key themes by 9 of the participants. This provided ten themes.
Firstly delivery by virtual means was seen by participants as an important way to help address barriers in accessing nature. They reported the virtual delivery was made more real by the quality of the visual materials used and accompanying sounds of nature. The use of visualisation exercises helped participants to gain a sense of immersion in a natural environment, while the use of mirroring of physical activities resonated deeply with some participants. I thought this was a powerful quote relating to this aspect - “ It’s so important to some of us. I used to love hiking and skiing in the outdoors and. . . I thought that was not available to me, then it has truly become available through this, it’s amazing!”
The delivery of the sessions by disabled guides was seen as a soothing and skilled facilitation by the participants, providing a sense of compassionate understanding and connection along with the sense of being valued. The group dynamics underlined the importance of peer support and the provision of a safe space within which to share emotions and experiences.
The forest-bathing approach supported participants to connect deeply with nature and to notice subtle details that they had not previously. This included greater awareness of sensations, such as feeling the breeze from an open window and from touching the natural items they had selected for the sessions.
The mindfulness element of forest-bathing provided both a sense of calmness during the sessions and a break from daily concerns for many of the participants. This enabled a deep sense of relaxation, with some participants reporting improvements in the quality of their sleep. This calming, restorative effect was identified as a key theme by the participants review of the thematic analysis.
Another key theme for participants was that of embodiment and pain relief. Participants felt that the forest-bathing sessions supported seeing themselves in more a holistic way rather than by health condition or reduced from the medical specialism within their treatment. They encountered the awareness of their pain alongside noticing the soothing sensations from nature. This provided a positive connection to themselves and for some participants a relief from tension and pain sensations.
The forest-bathing activities invoked positive memories for many, of times spent in nature prior to their disability. However this also invoked complex emotions, as alongside these memories was the awareness of negative emotions arising from the loss of opportunities their disability presented. Many participants found the sessions helped them to “grieve in a good way” for this loss.
Participants reported positive emotions, such as happiness, from the sessions coupled with feeling motivated. These emotions were linked by participants to both the peer support the group provided and from the multi-sensory connection to nature.
Agency was hugely important to participants who welcomed the adaptive nature of the sessions and how this allowed them to make the sessions individually meaningful. These adaptations were carried on after the sessions and at the one month follow up many of the participants reported containing to use nature connection and the forest-bathing activities as part of their ongoing self-care.
The experience of nature provided participants the opportunity to identify metaphors for themselves which were personally instructive and meaningful. Several participants noted that the forest-bathing activities helped them to form new perspectives of nature while the peer support provided a sense of being seen and having experiences validated.
Lastly the participants felt that the activities provided them with a sense of belonging, both within nature and as part of a community. This was facilitated by the common experiences of the participants, the sense of inclusion and acceptance they had towards each other and by the connection with nature, which afforded some with a sense of being part of something bigger.
While the results are limited by the subjective interpretation of participants words and survey responses I think there is real strength in how the analysis was undertaken, especially having a number of the participants help identify key themes. A further strength of the study is the use of follow-up data one month after the sessions.
The study provides real insight into how a carefully planned and delivered virtual method of forest-bathing can provide an accessible way of supporting people with mobility disabilities to connect with nature. The feedback underlines how important this was to the participants and how it provided ways for them to continue that connection with nature. It was also striking how the forest-bathing sessions helped to address the feeling of being valued less and excluded that many disabled individuals sadly experience.
“Most of us think we know woodlands and forests. Instinctively, perhaps – our ancestors came from the trees. We have known woodlands our whole lives, their shapes and textures, even if we cannot name the species of trees nor the birds we hear in their canopies. We walk our woods in the evenings or at weekends, in our spare moments of time, and they are familiar to us.”
Wyl Menmuir, writing in his book The Heart of the Woods illustrates the relationship many have to woods and forests, as familiar places, which can invoke a sense of attachment and place.
Across the two forest-bathing posts the evidence, despite study limitations, suggests that the slowing down and paying close attention to our surroundings, using all of our senses, can provide health benefits, at least in the short term. These health benefits should be available to all and there is increasing awareness and adaptations being made to address the key barriers for individuals with disabilities to engage and connect with nature. In this post that has only been considered from a forest-bathing perspective, of which there is an apparent scarcity of research even though the guided, multi-sensory aspects of forest-bathing appear as suggestions for addressing some of the barriers.
Writing this edition of Compassionate Nature has underlined two items on my list of topics to cover in future editions. One is to explore in greater detail key study design considerations, as I am aware that talking about things like effect sizes and blinding are very academic, although understanding them is key to evaluating the results of research. The second topic is to explore the issue of accessibility to nature for individuals with disabilities in much greater detail. Posts on these topics will appear in the near future.
Despite some of the limitations in study designs, key aspects of forest-bathing do appear to provide real health benefits. The challenge is how access to those health benefits is enabled for everyone equally.
As ever thanks very much for reading Compassionate Nature. Until next time, look after yourself and enjoy noticing nature in all of its subtle details.
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References
McEwan, K., Krogh, K. S., Dunlop, K., Khan, M., & Krogh, A. (2023). Virtual forest bathing programming as experienced by disabled adults with mobility impairments and/or low energy: A qualitative study. Forests, 14(5), 1033. ; https://doi.org/10.3390/f14051033
Simpattanawong, D., Li, Q., & McEwan, K. (2024). A controlled trial comparing the impact of guided forest bathing or a mindful urban walk on heart rate, blood pressure, and mood in young Thai adults. People and Nature, 6(6), 2577-2586. https://doi.org/10.1002/pan3.10744