Can Forest Therapy Aid Hospital Recovery?

I was at a dinner party early in the year, chatting with the lady next to me about my work in Nature Connection. She had never heard of Forest Therapy, nor why it might benefit physical and mental wellbeing. Although I deeply believed in its power, I found myself struggling to articulate it clearly in the moment. I realised that if I couldn’t explain it simply, I would miss opportunities to share something profoundly supportive – not just for individuals, but potentially for patients recovering in hospitals.

A few months later, I found myself on the other side of the experience. After being admitted to hospital with pneumonia and spending 24 hours on the ward, I was discharged into the care of my partner. The first place we went wasn’t home, but Burrator, a beautiful part of Dartmoor and one of my favourite spots in nature.

The shift I felt was immediate and profound. Where there had been white and grey solid walls in the hospital, I was now immersed in a rich and moving terrain of colour and experience. Where the air in hospital had been heavy, disinfected, and sterile, here it was fresh, cool, and alive with smells that touched something ancient and deeply human in me. And where the hospital surfaces had all been stainless steel or plastic, I could now run my hands over ribbed bark, soft moss, and a hundred other natural textures that grounded me back into my body.

That afternoon I realised something important: hospitals are essential for treating illness, but nature has a unique power to heal the person. This experience ignited a passion in me to help bridge the two – to support recovery by bringing nature connection into healthcare settings.

This essay is my attempt to articulate how Forest Therapy works, from a medical and scientific perspective, to support patients in recovery. It is also designed to help me share a clear “elevator pitch” with doctors, nurses, and other health professionals: why they should consider this work, and what the evidence says about how it supports healing.

What is Forest Therapy?

Forest Therapy, also known as Shinrin-Yoku or Forest Bathing, is an evidence-based therapeutic practice involving immersion in forest or natural environments. It engages all five senses—sight, sound, smell, touch, and even taste—to promote physiological and psychological restoration (Li, 2010; Hansen et al., 2017).

Unlike physical exercise or meditation, Forest Therapy is about slowing down and deepening one’s sensory experience of nature. It might involve observing leaves closely, listening to birdsong, listening to one’s breath, or simply touching the textures of bark and soil.

The discipline of Forest Medicine, born in Japan in the early 2000s, has been formally studying these effects through controlled experiments. The goal is to support recovery, prevent non-communicable disease, and enhance mental health through nature immersion (Li, 2018).

Attention Restoration Theory (ART), developed by Stephen and Rachel Kaplan, proposes that certain environments can help restore depleted cognitive resources, particularly the ability to direct and sustain attention (Kaplan & Kaplan, 1989; Kaplan, 1995). Directed attention—used in tasks such as problem-solving, studying, or decision-making – requires effort and can become fatigued over time, resulting in mental exhaustion and reduced performance.

Natural settings, such as forests, parks, or even views of greenery, help counteract this fatigue through a mechanism known as involuntary attention, or soft fascination. Unlike directed attention, soft fascination is effortless and restorative. Elements such as rustling leaves, the play of light and shadow, or birdsong gently hold one’s attention without requiring cognitive effort, allowing the directed attention system to rest and recover (Kaplan, 1995).

Evidence supports that even passive exposure to natural elements can trigger this restorative process. For example, a study conducted at MIT’s Simmons Hall dormitory found that students with window views of greenery performed significantly better on directed-attention tasks than students whose windows faced buildings or walls. This effect occurred despite the students not actively engaging with the view, demonstrating the power of soft fascination (Sullivan, Kuo & DePooter, 2004).

According to Kaplan and Kaplan (1989), restorative environments share four key qualities:

1. Being away – A psychological or physical escape from routine. This involves either a physical change of setting or a mental shift that creates a sense of separation from daily demands.
2. Extent – Richness and scope for exploration. A restorative environment is sufficiently expansive and coherent to feel like a “whole other world,” providing opportunities for exploration and immersion.
3. Fascination – Engagement without effort. The environment contains stimuli that effortlessly capture attention, allowing directed attention to rest.
4. Compatibility – The environment matches the participant’s needs and desires. The setting supports one’s purposes and inclinations, fostering a sense of ease and congruence.

Compatibility, the fourth quality, can be understood more deeply through six supporting dimensions described by Kaplan and Kaplan (1989):

1. Distraction – The environment is not highly stimulating or overwhelming, making it easy to become absorbed.
2. Deficit – The participant can make sense of the environment; it is understandable and coherent.
3. Danger – The environment feels safe and does not pose a physical or psychological threat.
4. Duty – The participant feels no obligation or sense of duty; engagement is voluntary.
5. Deception – The experience feels authentic and congruent, with no sense of being misled.
6. Difficulty – The environment does not present barriers to engagement; it is easy to interact with.

By fulfilling these four qualities and meeting the six dimensions of compatibility, nature supports mental clarity, emotional well-being, and improved focus. ART provides the theoretical foundation for many contemporary nature-based interventions used in education, therapy, urban design, and healthcare to promote psychological resilience and cognitive health (Kaplan & Kaplan, 1989; Kaplan, 1995; Kaplan, 2001).

In addition to Attention Restoration Theory, another key framework for understanding how nature supports recovery is Stress Reduction Theory (SRT), developed by Roger Ulrich (Ulrich, 1983; Ulrich et al., 1991). Whereas ART focuses on the restoration of depleted cognitive resources, SRT addresses the emotional and physiological stress response.

SRT proposes that humans have an innate, evolutionary predisposition to respond positively to natural settings because they signal safety and resource availability. This positive affective response can interrupt the body’s stress reaction—reducing activation of the sympathetic nervous system and supporting parasympathetic balance (Ulrich et al., 1991).

According to SRT, the visual characteristics of nature (e.g., vegetation, water, natural light, and open spaces) are particularly effective at lowering stress quickly and automatically, even without conscious awareness. Ulrich’s research demonstrates that these environments can lead to measurable physiological changes:

1. Reduced cardiovascular arousal: Lowered blood pressure and heart rate.
2. Neuroendocrine regulation: Decreases in stress hormones such as cortisol, adrenaline, and noradrenaline.
3. Improved emotional state: Increased positive emotions (e.g., calmness, interest) and reduced negative emotions (e.g., fear, anger, anxiety).

Perhaps the most famous example of SRT in action is Ulrich’s classic hospital study:

• Patients recovering from gallbladder surgery who had window views of trees experienced shorter hospital stays, required fewer doses of pain medication, and had fewer negative nurse notes compared to those whose windows faced a brick wall (Ulrich, 1984).
• Importantly, these benefits occurred without the patients actively engaging with the view, underscoring that the stress-reducing effects of nature can occur passively.

Ulrich and colleagues later found that even short exposures (3–5 minutes) to nature images or videos can reduce physiological stress markers (Ulrich et al., 1991). This makes SRT particularly relevant in hospital settings where access to actual greenery may be limited: visual nature cues alone can help lower stress and support healing.

Mechanisms supporting recovery: What science shows.

A large body of evidence demonstrates that exposure to forest environments has measurable physiological effects that aid recovery. Below is a breakdown of the key mechanisms:

a) Immune enhancement via NK (natural killer) cells

• Forest environments increase both the number and activity of NK cells and elevate cytotoxic proteins like perforin and granulysin in lymphocytes (Li, 2008; Tsunetsugu et al., 2010).
• A landmark clinical trial found that a three-day forest immersion raised NK cell levels for up to 30 days afterwards, compared to an urban trip with no such effect (Li et al., 2008).
• Even inhaling diffused tree essential oils (e.g. hinoki cypress) indoors produced similar increases in NK activity and decreased stress hormones (Li et al., 2009).

b) Stress hormone reduction and neuroendocrine modulation

• Forest exposure lowers cortisol levels, urinary adrenaline and noradrenaline, blood pressure, and heart rate, reflecting reduced sympathetic nervous system activation (Park et al., 2010).
• Essential oil inhalation of phytoncides similarly normalises neuroendocrine function and reduces cortisol, thereby enhancing immune regulation (Kuo, 2015).

c) Anti-inflammatory and metabolic regulation

• Forest Therapy reduces levels of pro-inflammatory cytokines and supports hormones such as adiponectin and DHEA-S, both linked to metabolic and mood regulation (Mao et al., 2012).
• By lowering chronic inflammation, forest exposure helps prevent conditions like diabetes, cardiovascular disease, and depression (Chen, 2019).

d) Cardiovascular and autonomic stability

• Patients exposed to nature demonstrate reduced blood pressure and heart rate and improved parasympathetic balance, aiding cardiovascular recovery and autonomic regulation (Lee et al., 2011).

e) Improved sleep, mood, and mental wellbeing

• Studies show measurable improvements in sleep quality, reduced fatigue, and better scores on mood scales (e.g. anxiety, depression, anger) after forest therapy sessions (Morita et al., 2007).
• Even simulated nature—such as window views of trees or images—can reduce post-surgical complications and pain medication needs (Ulrich, 1984).

Phytoncides are antimicrobial volatile organic compounds released by trees. These include monoterpenes such as alpha-pinene, beta-pinene, and limonene. Research shows they are a key mechanism through which forests influence immune and psychological function (Li, 2008).

• Inhalation effects:
  • ↑ NK cell activity and cytotoxic protein expression
  • ↓ Cortisol, adrenaline, and noradrenaline levels
  • Neuroendocrine balance restored, supporting immune regulation (Li et al., 2009)
• Antimicrobial and anti-inflammatory properties:
  • Direct antibacterial, antiviral, and antifungal effects may support immune resilience (Chen, 2019).
  • Modulation of pro-inflammatory cytokines enhances recovery and reduces chronic inflammation risk.
• Sensory and psychological benefits:
  • Pleasant natural scents reduce anxiety and improve mood, which further supports immune health and pain tolerance.

Forest Therapy in hospital recovery: practical application

Although direct access to forests is not always possible, hospital settings can integrate Forest Therapy principles in accessible ways:

1. Views of nature: Even a window view of trees speeds post-operative recovery, lowers pain, and shortens hospital stays compared to urban views (Ulrich, 1984).
2. Virtual or sensory nature: Projected nature imagery and soundscapes can lower stress and anxiety in patients unable to leave their beds (Anderson et al., 2017).
3. Phytoncide diffusion: Using safe essential oil diffusers with forest tree oils (e.g. hinoki, pine) may replicate some NK-boosting and stress-reducing effects observed in forests (Li et al., 2009).
4. Hospital gardens or green walks: Guided short sessions in hospital gardens focusing on sensory awareness can foster fascination and the “being away” quality of ART

In summary I would use these four key points when pitching this work to medical professionals:

• Clinical evidence: Peer-reviewed studies show measurable increases in NK cell activity, reductions in stress hormones and pain, and improved recovery outcomes—including shorter hospital stays.
• Rapid impact: Short exposures—even two hours per week of nature or simulated nature – produce significant physiological and psychological improvements lasting days or weeks.
• Cost-effective and low risk: Forest Therapy is non-pharmacological, easy to integrate, and has minimal side effects, while potentially requiring less pain medication, anxiety medication, and readmissions.
• Holistic patient benefit: Supports immunity, mood, sleep, and cognitive clarity—complementing standard medical treatment by healing the person, not just the illness.

In conclusion, Forest Therapy offers a scientifically supported, multi-mechanism intervention that can enhance hospital recovery. It stimulates immune function (especially NK cells), reduces stress and inflammation, improves sleep and mood, and restores cognitive focus.

As I experienced first-hand at Burrator, nature offers something hospitals cannot: the opportunity to reconnect with life beyond the walls, to feel the textures, smells, and rhythms that remind us of our own aliveness. Hospitals treat illness, but nature heals the person. 

Forest Therapy can – and should – be used to bridge these worlds.

References

• Anderson, K., et al. (2017). Virtual nature and its effect on hospital patients: stress and recovery. Link
• Chen, C. (2019). Nature’s pathways on human health. Link
• Hansen, M. M., et al. (2017). Shinrin-yoku (forest bathing) and nature therapy: a state-of-the-art review. Link
• Kaplan, R. & Kaplan, S. (1989). The Experience of Nature: A Psychological Perspective. Ann Arbor, MI: Cambridge University Press. Link
• Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. Journal of Environmental Psychology, 15(3), 169–182. DOI
• Kaplan, R. (2001). The Nature of the View from Home: Psychological Benefits. Environment and Behavior, 33(4), 507–542. DOI
• Kuo, M. (2015). How might contact with nature promote human health? Link
• Lee, J., et al. (2011). Effects of forest bathing on cardiovascular function. Link
• Li, Q. (2008). Effect of forest bathing trips on human immune function. Link
• Li, Q. (2010). Effect of forest bathing on human health. Link
• Li, Q. (2018). Forest medicine: From the roots up. Link
• Mao, G., et al. (2012). Therapeutic effects of forest bathing on metabolic parameters. Link
• Morita, E., et al. (2007). Psychological effects of forest therapy. Link
• Park, B. J., et al. (2010). Physiological effects of forest therapy. Link
• Sullivan, W. C., Kuo, F. E., & DePooter, S. F. (2004). The fruit of urban nature: Vital neighborhood spaces. Environment and Behavior, 36(5), 678–700. DOI
• Tsunetsugu, Y., et al. (2010). Forest environments and immune function. Link
• Ulrich, R. S. (1984). View through a window may influence recovery from surgery. Link
• ·  Ulrich, R. S. (1983). Aesthetic and affective response to natural environment. In I. Altman & J. F. Wohlwill (Eds.), Behavior and the Natural Environment (pp. 85–125). Springer.
• ·  Ulrich, R. S. (1984). View through a window may influence recovery from surgery. Science, 224(4647), 420–421. Link
• ·  Ulrich, R. S., Simons, R. F., Losito, B. D., Fiorito, E., Miles, M. A., & Zelson, M. (1991). Stress recovery during exposure to natural and urban environments. Journal of Environmental Psychology, 11(3), 201–230. DOI