The Science
Nature Rx: We Need Nature
We believe that safe access to green spaces and nature exposure are fundamental human needs that everyone deserves to be happy and healthy. As humans, we’ve spent thousands of years primarily in the outdoors and evolved with close proximity to nature, so our bodies and brains are especially attuned and responsive to nature cues.
Physical Wellbeing:
Spending time in natural environments offers a simple, powerful way to protect your heart by actively reducing the body’s physiological response to stress. In fact, research demonstrates that both walking through a nature reserve and simply viewing trees from a window promote a significantly faster and greater decline in blood pressure compared to urban settings (Hartig et al., 2003).
“Green exercise” is any physical activity performed outdoors in natural environments, such as walking, running or biking in nature. These and other physical activities have been shown to improve heart rate variability (HRV), which is an indicator of heart health and stress management (Bikomeye JC, et al. 2022).
Spending just 20 minutes connecting with nature can help lower stress hormone levels for those living in urban environments. This “nature pill” is flexible and even just sitting or lightly walking can measurably lower cortisol and amylase biomarkers, important indicators of stress and stress-related disorders. Strenuous activity not required (Frontiers | Urban Nature Experiences Reduce Stress in the Context of Daily Life Based on Salivary Biomarkers).
Accessibility to green landscapes, along with time spent in sunlight, has been shown to have benefits for mental health, including reducing anxiety that can result in insufficient sleep (National Institute of Health, PMC, 2016).
Modern lifestyles mean people often spend the majority of their time inside buildings, where trapped indoor pollutants frequently result in higher concentrations of toxic particles than what is found outdoors (Leung, 2015). This persistent exposure can lead to sick building syndrome and respiratory illnesses, highlighting why proper ventilation and spending time outdoors are crucial for long-term health (Leung, 2015).
Phytoncides, or wood essential oils, contain antibacterial and antifungal qualities that help plants fight disease. When people breathe in these chemicals, our bodies respond by increasing the number and activity of a type of white blood cell called natural killer cells or NK. These cells kill tumor- and virus-infected cells in our bodies and help boost our immune systems. In particular, aromatic evergreen trees, like cedar, seemed to have the strongest impact (Li et al, 2006 and Li, 2009).
The trillions of microbes living in and on our bodies, especially in our gut, play a major role in teaching and supporting our immune system. Microorganisms found in nature allow our immune system to stay in shape, but their absence (such as sterile environments, insufficient diet, or with antibiotic use), can lead to overreaction and chronic inflammation. This “hygiene hypothesis” suggests that the recent increase in chronic inflammatory conditions have become more common in places where humans no longer live in direct contact with microbes (NIH, PMC, 2025).
Natural play areas, those not designed or cultivated by humans, provide different structures in topography and vegetation that afford different types of play, i.e. trees for climbing, slopes for sledding and fields for running. These forms of play enhance physical activity and gross motor movements, improving coordination, speed, agility, power, and balance. When provided with a natural landscape in which to play, children showed a statistically significant increase in motor fitness (Fjortoft, 2004).
Mental Wellbeing & Cognitive Performance:
Spending time in natural environments has been consistently shown to reduce anxiety, improve mood, and promote overall mental well-being. Research indicates that even short, regular exposures to green spaces can have measurable benefits. From walking on a trail to gardening or forest bathing, the activity chosen is less important than the relaxation it gives the participant. Strive for short breaks each day up to 120 minutes per week to make it part of your routine.
Rumination, or when the brain fixates on a negative experience or emotion, can lead to depression if unabated. Walking in natural environments is linked to “soft fascination” and a “sense of being away,” which is a positive distraction from rumination. People who walked in natural areas showed decreased activity in a region of the brain associated with depression over those that walked the same amount of time in an urban environment (Bratman, Hamilton, & Hahn, 2015).
Natural environments (and even views or sounds of nature) gently capture attention without the pressure to focus deeply, and this cognitive reset clears the mind and restores the brain’s ability to focus. “Attention Restoration Theory” posits that nature creates opportunities to engage in “soft fascination,” which allows the mind to rest and reflect, and restores its ability to focus (Positive Psychology).
Time in nature has a restorative effect on our attention span. Memory and attention spans also benefit from time in nature, with University of Michigan psychology researchers pointing to a 20% improvement after spending an hour interacting with nature — an improvement that was consistent across different seasons and temperatures (Berman et al., Psychological Science, 2008).
“Twenty minutes in a park setting was sufficient to elevate attention performance relative to the same amount of time in other settings (i.e. a well kept urban or neighborhood street). These findings indicate that environments can enhance attention not only in the general population but also in ADHD populations. ‘Doses of nature’ might serve as a safe, inexpensive, widely accessible new tool in the tool kit for managing ADHD symptoms.” (J. of Att. Dis. 2009; 12(5) 402-409, Children With Attention Deficits Concentrate Better After Walk in the Park, Sage Journals, Taylor & Kuo, 2009).
Community Wellbeing:
Time spent in places with natural landscaping can encourage social interactions and integrations, particularly in older adults. Green landscapes with abundant vegetation and useful common spaces in urban areas are much more than aesthetic amenities — they are social infrastructure that supports community wellbeing and acts as a catalyst for social life (Kweon, Sullivan & Wiley, 1998).
While direct contact with nature provides the greatest benefits, a study from Oregon shows that even just watching nature videos can help curb aggression. Researchers found that over the course of a year, inmates in a maximum security prison with access to nature videos reported feeling significantly calmer and violent infractions were reduced by 26% (Nadkarni et. al, 2017).
The Conservation Foundation’s Nature Rx initiative educates local communities and partners with health-focused community organizations, healthcare facilities, park districts, and forest preserves to connect people with nature and the outdoors to improve their health and wellbeing. Through workshops, media, engagement activities, and educational materials, we are educating people about nature wellness activities and the physical, mental, and community health benefits of getting out into nature and exploring the endless ways a connection to nature improves our quality of life.