Nature as Health Therapy: A Medico-Scientific Perspective
- sarah8648
- 1 hour ago
- 10 min read
By Sarah Bersey BSc (hons) Pg Dip
The stress landscape:
Over the past decade, self-reported excessive stress and anxiety among adults have shown marked increases across multiple countries and demographic groups.
In the United States, the 2024 National Survey on Drug Use and Health (NSDUH) found that 7.4% of adults aged 18 and older reported experiencing moderate or severe anxiety symptoms—a notable metric that was first systematically tracked in 2024 (SAMHSA, 2024).
When stress becomes a problem:
Looking ahead, projections for 2025 estimate that approximately 42.5 million U.S. adults will be living with an anxiety disorder, making it the most common mental health condition in the country (LAOP Center, 2025). This represents a dramatic shift from pre-COVID pandemic baselines, with the U.S. Census Bureau's Household Pulse Survey documenting that the percentage of adults reporting symptoms of anxiety and depression surged from 11% to 40% between 2019 and 2020 (Census Bureau, 2020).
The American Psychiatric Association's 2024 annual mental health poll provides additional context on the drivers of this increase. Their survey identified:
health concerns (65%)
money worries (63%)
economic instability (64%)
as the top day-to-day stressors affecting U.S. adults (APA, 2024).
Women are approximately twice as likely as men to experience anxiety disorders (ADAA, n.d.).
On a global scale, the World Health Organization's 2023-2024 mental health assessment estimates that anxiety disorders affect roughly 3.8% of adults worldwide—approximately 300 million people—with one-year prevalence of generalized anxiety disorder (GAD) at approximately 7% of adults globally (WHO, 2024).
Globally, low-resource (Bie et al, 2024) and low-income urban populations (Hystad et al 2021) frequently experience disproportionately high levels of chronic stress, a condition made worse by systemic inequalities in access to restorative blue (water) and green (vegetation) spaces.
Despite the high prevalence of anxiety disorders, access to mental health services remains limited, with only 43.2% of those affected in the U.S. receiving treatment (ADAA, n.d.). It is not clear if this represents a low level of availability of talking therapies and/or prescribing pharmacological drugs to treat the effects of stress and anxiety, or a reluctance on the part of sufferers to seek medical help. Certainly, it can be surmised that those who are most likely to suffer the effects of chronic stress (low income urban residents), may also be the least likely to seek medical help (Hystad et al 2021).
It seems clear that even if we're not low-income urban dwellers, it's likely that we suffer from stress symptoms sometimes, or even frequently. The question is what we can do about it ourselves to build our resilience?
There are an enormous number of suggestions available - everyone has their tried and trusted de-stressor. Apart from resorting to recreational drugs, alcohol and/or smoking, which tend to lead to addiction and spiralling mental health problems, these can generally be broken down into the following types:
Reducing stress and anxiety involves active lifestyle management, such as
exercising regularly, practicing deep breathing, maintaining a healthy diet, and getting adequate sleep. (NHS 2022). Key techniques include connecting with others, taking "me time" for hobbies, limiting alcohol/caffeine, setting small goals, and using mindfulness or journaling to manage thoughts.
The case for exposure to nature:
Getting out into green and blue spaces would seem to combine several of these suggestions: exercise, setting goals, "me time", deep breathing and a space to practice mindfulness. Being out in nature has been associated with "stress buffering" (Nature stress buffering is the process by which exposure to natural environments acts as a protective factor, reducing the negative impact of daily stressors and social isolation on mental and physical health). Natural environments promote restoration by lowering cortisol levels, calming the nervous system, and reducing anxiety, fatigue, and anger. (Marselle et al 2019) "Nature restorativeness" can be modelled :
The restorative effects are thought to be a combination of the following factors:
(i) Stress Hormone Reduction Through Phytoncide Exposure
One of the most well-documented physiological benefits of nature exposure involves the reduction of stress hormones through inhalation of phytoncides—volatile organic compounds emitted by trees and plants. Research led by Dr. Qing Li and colleagues has demonstrated that forest bathing (Shinrin-yoku) significantly lowers salivary cortisol concentrations, along with adrenaline and noradrenaline levels, compared to urban environments (Li, 2022). These phytoncides stimulate parasympathetic nervous system activity and modulate the hypothalamic-pituitary-adrenal (HPA) axis, effectively dampening the physiological stress response. A 2024 meta-analysis confirmed that phytoncide exposure produces measurable immunological benefits, with significant increases in Natural Killer (NK) cell activation (effect size: 2.50; 95% CI [1.94–3.05]) (Lew & Fleming, 2024). This mechanism provides a biological pathway explaining why even brief nature visits produce immediate calming effects.
(ii) Attention Restoration and Cognitive Recovery
Attention Restoration Theory (ART), developed by Rachel and Stephen Kaplan, posits that natural environments replenish depleted directed attention resources through "soft fascination"—effortless engagement with natural stimuli that allows the brain's executive-attention system to recuperate. Recent empirical validation includes a 2023 field study where participants taking 50-minute walks in natural settings showed reduced anxiety, decreased rumination, and improved working memory scores compared to urban walkers (Bratman et al., 2023). Furthermore, a 2024 EEG investigation revealed that 40-minute nature walks enhanced neural markers of executive control, specifically increasing error-related negativity signals that indicate improved executive attention capacity (McDonnell & Strayer, 2024). These findings suggest nature exposure provides rapid cognitive recovery from mental fatigue, with implications for conditions involving attentional deficits such as ADHD and burnout.
(iii) Cardiovascular and Immune System Enhancement
Regular exposure to green spaces produces measurable improvements in cardiovascular function and immune competence. Studies consistently demonstrate that time spent in vegetation-rich environments lowers resting heart rate, reduces blood pressure, and decreases systemic inflammation—all key risk factors for cardiovascular disease (Keith et al 2024). Simultaneously, forest environments enhance immune surveillance through increased activity and numbers of Natural Killer cells, which are critical components of the innate immune system responsible for identifying and destroying virus-infected or malignant cells (Li & Kawada 2011). A narrative review examining greenspace and cardiovascular health identified multiple mechanisms including reduced inflammation, improved endothelial function, and decreased sympathetic nervous system activation (Keith et al, 2024). These physiological changes translate to tangible health outcomes, with epidemiological studies linking greater greenspace access to reduced cardiovascular mortality rates.
(iv) Mental Health and Psychological Well-being
The psychological benefits of nature therapy extend across multiple domains of mental health, with robust evidence supporting its efficacy for anxiety, depression, and trauma-related conditions. A systematic review of therapeutic nature activities—including gardening, hiking, horseback riding, and fishing—found consistent improvements in mood, self-esteem, and perceived overall health across diverse populations (Hudkins et al, 2024). Nature-based interventions have shown particular promise for patients with mild to moderate mental health conditions, with studies demonstrating reduced symptoms of PTSD, decreased social anxiety, and diminished feelings of loneliness (CHEGG, 2024). The therapeutic mechanisms appear multifactorial, involving stress hormone reduction, attention restoration, increased physical activity, and enhanced social connection through shared nature experiences. Clinical guidelines increasingly recommend "nature prescriptions" as complementary interventions alongside conventional treatments.
The research described above makes a compelling argument for us all to get out into nature in green and blue spaces regularly, so we should all try to include it in our schedules, either indvivdually or as family groups. However, other studies indicate that residents of economically disadvantaged neighborhoods often face a "nature gap," where the scarcity of parks, tree canopy, and accessible waterways limits opportunities for stress reduction and physical activity compared to wealthier counterparts. A study published inThe Lancet: Planetary Health found that individuals living in areas with low green space coverage reported significantly higher levels of psychological distress, with the disparity being most pronounced in low-income communities where environmental stressors like noise and pollution are also concentrated (Hystad et al., 2021).
Furthermore, the lack of safe, well-maintained green infrastructure in these areas prevents the "stress-buffering" effects typically associated with nature exposure, creating a feedback loop where high stress levels are maintained by the built environment itself (Bratman et al., 2019). While proximity to green space is linked to lower cortisol levels and improved mental health outcomes, low-income urban residents often must travel greater distances to reach quality parks, effectively reducing their utilization and the associated mental health benefits (Wolch et al., 2014).
For these reasons, community-led initiatives are vital for bridging the "nature gap" in urban areas, where nearly 47% of people lack access to green space within a 15-minute walk of home
By reclaiming underutilised spaces and fostering direct interaction, communities can improve both mental health and environmental resilience.
(Knill 2021)
Community actions that are being suggested or actively undertaken:
Transforming Underutilized Land:
Vacant Lot Greening: Communities can convert derelict or "wasteland" sites into community assets by clearing rubbish and planting native trees.
Pocket Forests and Meadows: Small-scale "micro-injections" of nature, such as wildflower meadows or mini-forests, increase habitat suitability in dense areas.
Guerrilla Gardening: Unofficial planting in neglected public spaces can introduce native species like prairie sage or sunflowers to detoxify soil and improve local aesthetics.
Shared Stewardship and Maintenance:
Community Gardens: These spaces foster social cohesion and bonding through shared care for resources.
"Friends" Groups: Voluntary organisations that steward local parks ensure they remain safe, inclusive, and well-maintained.
Wildlife Monitoring: Local groups can participate in citizen science by tracking pollinators, birds, or bats to inform conservation efforts.
Enhancing Built Infrastructure:
Green Built Interventions: Installing rain gardens, green roofs, and living walls helps manage stormwater while bringing nature to rooftops and facades.
Wildlife Corridors: Linking isolated green patches through "stepping stone" plantings or "green chains" allows wildlife to move through the urban matrix.
Animal Habitats: Installing bee hotels, bird boxes, and bat houses provides essential nesting sites in areas without natural hollows.
Other Engagement and Inclusion Strategies:
Co-Design Workshops: Involving residents—especially children and marginalised groups—in the design process ensures spaces meet actual community needs and feel safe.
Targeted Outreach: Programs like Nextdoor Nature work to recruit community organisers specifically in nature-deprived neighbourhoods to address environmental justice.
Educational Programming: Hosting "Green Gym" sessions, nature walks, or sustainable living workshops encourages people to use and value their local green spaces
(Drake 2025, Knill 2021)
The Benefits of Community Action:
Benefit Category | Key Outcomes |
Health & Wellbeing | Reduced stress/cortisol, improved mood, and increased physical activity. |
Social Cohesion | Reduced loneliness, stronger neighbourhood ties, and decreased crime/violence. |
Climate Resilience | Mitigation of the "urban heat island" effect and improved floodwater management. |
(Drake 2025, Knill 2021)
Conclusion:
Stress seems to be a part of modern life for all ages - everyone I spoke to about it from the ages of 8 to 80 was affected. At low levels, it can boost productivity, but can quickly become out of control and harmful. Research has shown that contact with nature is very beneficial for the sufferers of stress and anxiety, which is absolutely great for those who can include trips out into green and blue spaces into their lives and their families' lives. They will probably see benefits within a very short time.
However, those who are documented to have the greatest levels of harmful stress and anxiety, low income urban dwellers, may well require help in accessing nature, either through community transport schemes, or through neighbourhood greening interventions and community gardens/spaces.
If we can become involved in community projects, it is likely that they will benefit us all.
Useful References:
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American Psychiatric Association (APA).(2023). Stress in America 2023: A nation recovering from collective trauma. Retrieved from https://www.apa.org/news/press/releases/stress/2023/collective-trauma-recovery
Anxiety and Depression Association of America (ADAA). (n.d.). Anxiety Disorders - Facts & Statistics. Retrieved from https://adaa.org/understanding-anxiety/facts-statistics
Bie F, Yan X, Xing J, Wang L, Xu Y, Wang G, Wang Q, Guo J, Qiao J and Rao Z (2024) Rising global burden of anxiety disorders among adolescents and young adults: trends, risk factors, and the impact of socioeconomic disparities and COVID-19 from 1990 to 2021. Front. Psychiatry 15:1489427. doi: 10.3389/fpsyt.2024.1489427 [online] https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2024.1489427/full
Bratman, G. N., Anderson, C. B., Berman, M. G., Cochran, B., de Vries, S., Flanders, J., ... & Daily, G. C. (2019). Nature and mental health: An ecosystem service perspective. Science Advances, 5(7), eaax0903.
Bratman, G.N. et al. (2023) 'Nature May Be Key to Strengthening Our Attention', Psychiatric News, 12(12), pp. 6-7. Available at: https://natureandhealth.uw.edu/2023/11/nature-may-be-key-to-strengthening-our-attention/
CHEGG (2024) Student Mental Health Week: A guide to nature-based therapy [online] Available at: https://www.chegg.org/student-mental-health-week-2024-content/a-guide-to-nature-based-therapy
Climan, A. (2024) Green Spaces and Heart Health: A Natural Connection (2024) The Cardiology Advisor. Available at: https://www.thecardiologyadvisor.com/features/green-spaces/
Drake, D (2025) Nature Towns and Cities: Creating Greener Neighbourhoods and Brighter Futures [online] https://naturalengland.blog.gov.uk/2025/04/04/nature-towns-and-cities-creating-greener-neighbourhoods-and-brighter-futures/#:~:text=The%20programme%20has%20united%20a,the%20Northern%20Ireland%20Environment%20Agency.&text=Our%20Green%20Infrastructure%20Framework%20supports,green%20space%20close%20to%20home.&text=We're%20working%20with%20towns,more%20resilient%20places%20for%20everyone.
Hudkins, A., Greaves, L., Small, D., Bushway, M., Diaz, C., Wheartly, M., Murray, A., Winz, C. (2024)Therapeutic Nature Activities to Improve Well-Being: A Systematic Review American Journal of Occupational Therapy, 78(Supplement_2). [online] Available at: https://research.aota.org/ajot/article/78/Supplement_2/7811500166p1/25493/Therapeutic-Nature-Activities-to-Improve-Well
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