Nature Therapy: Can Time Outside Reduce Your Stress?

Are you feeling stressed out? Stress has become a way of life for so many of us these days. Uncertainty about the future, uncertainty about our health, our jobs, our families, our societies... we currently have more questions than answers and more stress than we know what to do with.

Now more than ever, the concept of nature AS therapy — “nature therapy” — might be the stress-fighting solution you are looking for. What if you could take a prescription for nature?

The negative effects of stress

Although not all stress is bad, chronic stress results in changes in your physical and mental health that contribute to long term illness and disease.

Stress affects your body

In your body, stress causes a surge of hormones, specifically adrenaline and cortisol, that results in a pattern of response known as “fight or flight.”

What is the fight or flight response? Your body literally prepares you to flee or fight, which means your heart beats faster, your muscles contract and your breathing speeds up.

Your body cannot tell the difference between a real life-threatening situation and the stress created by your constant worrying. In a real life-threatening scenario, you would run away or fight your opponent and the pattern would end. But with chronic stress, the pattern just goes on and on and on, eventually leading toadrenal fatigue.

Chronic stress can lead to significant long-term physical changes in your body which may impact your brain function, memory, cardiovascular system, digestive system and your immune system(1). Therefore, ongoing stress may leave you more susceptible to chronic health issues like high blood pressure, heart disease, and diabetes.

Stress affects your mental health

Your mental health also suffers when you are stressed. As a result of the changes in your body, stress may leave you feeling depressed, anxious, unable to focus or overwhelmed.

Some people may find they get easily annoyed, frustrated or angry when they are stressed out. Others suffer more intensely from body aches, or find it impossible to sleep. These symptoms may lead some people to turn to drugs or alcohol as a coping strategy, both of which can create further mental and physical health complications. These mental health changes can be a direct result of stress hormones and the energy shifts they cause in the body, including elevated blood pressure, rapid breathing, altered brain chemistry and impacts on the immune system(2).

Stress can become a vicious cycle that is reinforced by our daily habits. If you find yourself in constant stress, then it may be time to try some new ways of letting your body have a break.

Can nature reduce stress?

Spending time in nature to reduce stress is not exactly a new concept. We have long been told to “take it outside,” “walk it off,” “get some physical exercise,” and “breathe the fresh air.” Time in nature just makes sense when you’re at your wit’s end and need a break.

But how much time do you need?

Should you sit quietly, walk or run?

How often do you need to be in nature to have a positive impact on your stress levels?

What if you don’t live near a park or green space?

The exciting news is that scientists are rapidly closing in on what may become the first “prescription for nature” to treat stress(3). Here’s what you need to know.

What is nature therapy?

Nature Therapy is a broad term used to describe the concepts and techniques of improving physical or mental well-being by developing a connection with nature and the natural world.

First described as ecotherapy by Theodore Roszak (1933-2011), this is a holistic approach that sees human beings as part of the natural world. It links our modern issues and diseases with our shift away from living in close connection to nature(4,5). Therefore, nature therapy seeks to restore our connection through interactions with water, soil, plants, animals and natural places. These connections allow us to recharge our minds and our bodies.

Nature therapy became popularized by a reframing of the issue as “Nature Deficit Disorder” in 2005 with the publication of “Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder” by Richard Louv(6). Louv raised the issue that many of our modern health concerns, including obesity, attention deficit, early-onset diabetes and an ever-increasing list of mental and physical illnesses, are easily linked to our culture of inactivity and indoor living.

According to the EPA, the average American spends up to 90 percent of their day (21 hours) inside (7). Finding time to spend in nature could be more important than ever in our modern lives, and may represent a significant public health issue in terms of gaining access to green spaces.

Recent science behind nature therapy

The 120-minute threshold

A large scale 2019 study involving 19,806 participants looked at the relationship between recreation in nature and well-being(8).

This study identified a clear threshold of >120 min of time in nature spent within one week as being key to participants reporting better health during the past seven days. Surprisingly, spending 1-119 minutes did not differ significantly from spending zero minutes in nature. But once the threshold of 120 minutes in nature during a week was passed, significant increases in well-being continued to accumulate up to around 200-300 minutes, which represented a peak in benefits.

This 120 min/week threshold for achieving health benefits from time in nature turned out to be quite robust. The relationship held up even when nationality, individual health and amount of neighborhood greenspace were controlled for. It also held for people with serious illnesses and disabilities.

Perhaps most importantly, the threshold held regardless of what activity people chose for their outdoor nature exposure and regardless of whether they made several short trips into nature during the week or one long excursion of 120 minutes or more.

While the researchers caution more studies are needed to examine this relationship as a prescription for wellness, these results suggest that time in nature has significant potential for improving individual health and reducing stress.

Reduced biomarkers for stress

Another 2019 study examined stress using salivary cortisol as one of the indicators to determine whether spending time in nature could result in measurable decreases in stress hormones(9).

The researchers found that salivary cortisol dropped by more than 21 percent per hour when participants spent time in nature. This drop is in addition to the 11 percent drop in salivary cortisol that is associated with normal daily rhythms, meaning the results are not an artifact of normal body chemistry.

Peak benefits were seen at the 20-30 minute mark, at which the decline in cortisol levels was the fastest. Longer durations in nature continued to accrue benefits, but at a slower rate of change than at the peak.

One of the key findings of this research is that the reduction in salivary cortisol levels was independent of the participant’s activity in nature. In other words, it did not matter if the person was sitting quietly, walking, or doing more vigorous activities in nature in order to see the resulting drop in cortisol.

Vitamin D and time outside

Vitamin D is commonly referred to as the sunshine vitamin because our skin makes vitamin D when exposed to sunlight. Two recent studies highlight the significance of vitamin D in relation to sun exposure and our immune responses.

In 2019, researchers in Japan found a high frequency of vitamin D deficiency among the 3,495 pregnant women participating in the study looking at lifestyle factors and vitamin D deficiency(10). More than 73 percent of these pregnant women had blood serum levels for Vitamin D of less than 20 ng/mL, classifying them as vitamin D deficient. Nearly 11 percent of participants were actually severely deficient (at levels below 10 ng/mL).

Lifestyle choices of these pregnant women played a role in these results. Factors associated with having normal vitamin D levels above 25 ng/mL included:

• Spending 15 minutes in the sun on more than five days in a week
• Consuming more than 7 ng/mL of vitamin D through their diet
• Supplementing with 100-200 IU/day of vitamin D (only 5 percent of participants)

The study showed that dietary vitamin D alone was insufficient in both the winter and spring to prevent deficiency. The study suggests that lifestyle changes which include spending time in the sunlight can have a significant effect on vitamin D levels, which are important for long-term health and for successful pregnancies.

Vitamin D and our immune response

Over the last 10 years, Vitamin D deficiency has been identified as a global health issue affecting more than 1 billion people and contributing to the incidence of systemic infections, autoimmune diseases and susceptibility to bacteria and viruses(11). In clinical trials, low serum vitamin D has been associated with respiratory tract infections, including epidemic influenza(12). The importance of vitamin D to a healthy immune response supports the concept of getting outside and into the sunshine on a regular basis to create a natural supply which is clearly important to good health.

What are the best options for nature therapy?

There are no right or wrong ways to include nature in your weekly routine. Any time spent outside and in nature is going to have a positive impact on your physical and mental health.

But to get the most benefits, here are some tips and activities that top the charts for nature therapy:

Based on the studies reported here, a good place to start is aiming for 120 minutes of nature experiences each week, in sessions of at least 20-30 minutes at a time. This will increase your chances of experiencing the stress reductions noted in the studies. Choose any activity or meditation pattern that suits your physical and mental status at the time.

Remember to moderate your direct exposure to the sun, and use sun protection, so that your skin can create Vitamin D while still minimizing your chances of overexposure (13).

Activities suitable for creating a nature therapy session include:

• Taking your exercise routine outside
• Enjoying outdoor activities like walking, running, biking or swimming
• Meditating outside
• Spending time in a forest
• Gardening
• Spending time in the company of animals outside
• Being near running water
• Spending in or near the ocean
• Surfing

If you are trapped inside, research suggests that viewing images of nature (14) and listening to natural sounds (15) can provide some stress reduction. Additionally, immunity-boosting supplements, such as ashwagandha or probiotics, may complement other stress-reduction techniques.

In summary

Connecting with nature by spending time outside in natural settings has significant health benefits, regardless of your level of activity or physical fitness. Young or old, time in nature can reduce your stress hormones and improve your sense of well-being.

We are approaching a time when physicians will have enough information to prescribe specific types of nature therapy best suited for your personal situation and health issues. In the meantime, finding ways to spend time outside will boost your immunity, improve your focus, lighten your mood, and reduce your risk factors for serious health complications.

Sue Senger - Contributing Writer, Physician’s Choice