Dr. Michael Ruscio, DC is a clinician, Naturopathic Practitioner, clinical researcher, author, and adjunct professor at the University of Bridgeport. His work has been published in peer-reviewed medical journals and he speaks at conferences around the globe.
Spending Time Outdoors Is a Powerful Way to Boost Your Physical and Mental Well-Being
Research shows that being in nature has a profound effect on reducing symptoms of stress, anxiety, and depression.
Spending more time in nature also correlates with a decreased risk of all-cause mortality, cardiovascular disease, stroke, and neurodegenerative disease.
Even photos of natural spaces can have a similar positive effect to being outside, and as little as five minutes spent looking at photographs of green spaces reduced stress.
Unlike many other health tools, getting outside and spending time in your local green spaces is usually free and doesn’t require training.
It seems like many of us are constantly searching for the next breakthrough method to relieve stress and bring our nervous system and mental energy back into balance.
Different forms of exercise, meditation, and even vagus nerve stimulation can be excellent tools to relieve stress, but stress relief doesn’t always have to be so intentional or active. Sometimes you just need to go outside, disconnect from devices and distractions, and spend some time in your local green spaces (preferably on a regular basis).
The ability of nature to lower stress levels is truly profound and perhaps underutilized by many of us when we think of ways to implement self-care in our lives. In this article, I want to highlight how being in nature reduces stress, explain the biological mechanisms behind this stress reduction, spotlight a particularly well-designed study that shows how exposure to nature improves both subjective and objective markers of stress in individuals, and speculate how much time we should spend in nature to see benefits.
The Effects of Nature on Both Physical and Psychological Stress
Research supports that spending time in natural settings improves markers of both physical and psychological (subjective) stress. We can see measurable improvements in [1, 2, 3, 4]:
Overall mood and emotional wellbeing
Autonomic nervous system activation
Immune system function
Risk of developing chronic illness
Risk of all-cause mortality
A systematic review of randomized controlled trials (RCTs), nonrandomized controlled trials, and observational research found that people who spent time in nature had less anxiety and depression afterward . Another review found that after time in nature, people said they experienced lower self-reported stress, and their bodies reflected this perception with reduced amygdala activation, improved cortisol (stress hormone) and blood pressure levels, and calmer autonomic nervous systems .
Even photos of nature can improve mood and reduce stress. When photos of urban streets with cultural attractions have lots of vegetation, potential tourists searching online tend to have more positive emotional experiences . Similarly, spending five minutes looking at photos of green spaces can help people recover from stress by boosting parasympathetic activity . Perhaps it’s no wonder that landscape paintings and photography have been a staple of many cultures and art traditions throughout human history — we actually feel better when we see them.
If you don’t have regular access to outdoor green spaces, hanging up nature photography, watching nature shows, or even putting a nature wallpaper on your phone and computer might be a good idea for your health and self-esteem.
Calming the Amygdala
Research tells us that one of the most remarkable positive effects of nature on our physical health is downregulating the amygdala. The amygdala is a brain structure involved in emotional processing. Although we typically refer to the amygdala in the singular, it technically has two parts: one on each side (toward the center and bottom) of the brain.
These almond-shaped emotional hubs of the brain are usually hyperactive in people with depression, and inflammation in the body influences the way they function . Both chronic and perceived stress can activate inflammatory responses in the amygdala , and contribute to the onset of depressive symptoms . Amygdala activation also appears to stimulate anxiety, conditioned trauma responses, and the fight or flight response .
Therefore, we can seedecreased amygdala activation as a physical sign of stress reduction and returning the nervous system to a calm, balanced state. While there are many practices that work to decrease amygdala activation, such as meditation, breathwork, and programs like the Gupta brain rewiring program and DNRS, spending time in nature is one of the lowest-effort remedies and potentially the most accessible (depending on where you live). After all, going outside is free and you don’t need any training in how to do it.
Decreased Risk of Chronic Illness and All-Cause Mortality
It’s a little misleading to say that spending time in nature can lead to a lower risk of chronic illness and all-cause mortality because there’s no causal data suggesting that one directly comes before and therefore leads to the other. However, it is accurate to say that spending time and/or living in nature is associated with a lower risk of some chronic diseases and a lower risk of dying from any cause.
In other words, people who have more green exposure also happen to have better health outcomes, on average, but the studies that show this don’t provide the kind of evidence that can tell us why.
Most research looking for relationships between natural spaces and all-cause death or chronic disease is observational. A number of meta-analyses have found that the more we are exposed to green spaces, the less likely we are to die prematurely from:
For example, a 2022 meta-analysis analyzed 53 observational studies with more than 100 million participants from 18 countries to determine the relationship between exposure to green space and illness or death from cardiovascular disease.
This analysis found that for every 0.1 unit increase in the measure of green space, the odds of dying of cardiovascular disease, ischemic heart disease, cerebrovascular disease, and of having a stroke decreased 2–3 times. This does not prove that green space protects us from cardiovascular disease, but it suggests the possibility that it might . At the very least, access to green space might help protect your cardiovascular health on some level.
Now that we have a little more context around how being in nature reduces stress, let’s take a closer look at one well-designed study that highlights the benefits of nature on the stress response.
Spotlight Study: Walking in Nature to Reduce Stress
I want to highlight an excellent study that evaluated the impact of walking in nature on stress levels. Researchers wanted to know what kind of impact time in nature has on stress — both subjective (how individuals report they feel) and objective (by looking at amygdala reactivity during a functional MRI scan) . This excellent study was set up like this:
Step one: Researchers give the study participants a questionnaire assessing their baseline emotional state.
Step two: Individuals undergo an fMRI scan while being exposed to stressors, including looking at unsettling facial expressions and performing complicated math problems.
Step three: Individuals are randomized into two groups — one group goes for an hour-long walk in nature, the other goes for an hour-long walk in an urban environment.
Step four: Individuals repeat the fMRI while being exposed to the same stressors as before.
Step five: Individuals repeat the questionnaire assessing their emotional state.
Researchers were able to observe the brain activity of each group and found that those who spent time in nature had significantly reduced amygdala activation. Those who walked in an urban setting did not, indicating that the benefits came from more than just exercise. This assessment gives us physical evidence that exposure to nature (along with walking) positively changed the brain’s reaction to stress.
Additionally, those who spent time in nature had improved attention and better mood. Again, those who walked in an urban area instead did not see these beneficial effects .
How Much Time Should We Spend in Nature to Reduce Stress?
So, we see from the study I just highlighted that an hour-long walk in nature can significantly reduce stress levels as measured by amygdala activity and subjective measures of mood and attention. What else can we say about why nature can help us de-stress, and how long we need to experience benefits?
Although it’s not clear yet which characteristics of the natural environment contribute to reducing stress, some possible features include the quietude, better air quality, sun exposure, promotion of physical activity, and positive social interactions that may improve mindfulness, reduce rumination, and boost resilience .
As for how long you should spend in nature to see optimal health benefits, we still need more research to answer that question. However, we do know that as little as five minutes spent looking at photographs of green spaces reduced stress , and longer exposure is likely better both for your short and long-term health [10, 11]. A good target to aim for seems to be 120 minutes per week (two one-hour walks), based on research. But feel free to start small with 30 minutes or even just five minutes a day if you need an easier on-ramp to kickstart your nature habit.
Again, if you don’t have convenient nature access, you can still get some of the features of the natural environment by going for walks with friends or family, exercising, finding or creating a quiet retreat space in your home, and vacationing in natural spaces when you have the chance.
Ideally, future research will compare the effects of different activities (bird watching, meditating, walking, or running alone or with others) in nature, but plenty of research shows that physical activity, good air quality, mindfulness, and positive social interactions are good for us in general.
For now, you can think of spending time in nature as a low to no-cost general stress reliever, and enjoy it for as much time as you can for your physical and mental health.
How Can You Spend More Time in Nature?
Most of us could all use a little less stress and a little more resilience in our lives, and spending time in nature seems to check both boxes. If you don’t do so already, how can you spend more time in the green spaces where you live? It might be as simple as taking a walk on your lunch break or exploring local parks in your area.
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