The Nature Pill — Your Doctor's New Prescription for Stress

You’ve probably heard that time immersed in nature can heal you. But if you’re like me, you’re looking for details.

How much nature?

What type of nature, exactly?

And let’s get real: How long do you have to “immerse” yourself?

For a long time, we haven’t really had answers to these questions. But a new study published in Frontiers Psychology gives us more specifics on how exactly we can use nature to improve our health.

Is Nature the Antidote to Stress?

We’ve long known that nature is associated with lower stress levels. For example, one study suggests a beneficial association between green space exposure and reduced stress, positive mood, less depressive symptoms, better emotional well-being, improved mental health and behavior, and decreased psychological distress in adolescents. Another study showed that there are significant differences in disease prevalence between residents living in very green and less green settings, even after controlling for socioeconomic status. Previous research has been able to draw associations between time in nature and wide range of health issues, including:

• Depression
• Anxiety disorders
• Diabetes mellitus
• Various infectious diseases
• Cancer
• Healing from surgery
• Obesity
• Birth outcomes
• Cardiovascular disease
• Musculoskeletal complaints
• Migraines
• Respiratory disease

Neighborhood greenness has even been consistently associated with a greater life expectancy. Finally, a study showed that people who move from a less green to a more green area have significantly better mental health in the three post-move years, which suggests the benefit isn’t short-lived but instead persists over many years, possibly even indefinitely.

Now, moving into the mountains or forest isn’t an option for most of us, but many of us could find ways to build nature time into our day — or at least our week — which is why a new study published in Frontiers Psychology is particularly helpful. The results don’t just show us that nature can improve our mental and physical health, they provide us with the details.

Can 20 Minutes of Nature Reduce Stress?

This study was the first time researchers have ever looked at the effect of nature on physical health, where the participants were mainly able to choose the time of day, duration, and type of nature exposure (NE). This is a big deal since it means the participants were able to incorporate nature into their lives in a way that worked for their schedule, budget, and personal preferences.

In fact, during the 8 week study period, the only instructions the 36 participants were given was to spend time in outdoor places at least 3 times a week for at least 10 minutes. Sounds pretty doable, doesn’t it?

To measure the effects of the natural exposure on stress levels, the researchers took saliva samples before and after a NE at four points throughout the 8 weeks. They specifically measured:

• Cortisol levels: Cortisol is the body’s main stress hormone. High cortisol levels are a good predictor of chronic stress, and have been associated with a wide range of physical health issues, such as fatigue, depression, pain, and memory impairments.

• Alpha-amylase levels: This enzyme is produced at higher levels when the body is under stress, and is widely used as a measurement of stress levels.

The results showed that the intervention produced a twenty-one percent per hour drop in salivary cortisol , and a twenty-eight percent per hour drop in alpha-amylase . The study showed that the participants who spend between 20 and 30 minutes in nature got the most benefit (more time in nature did lead to less stress, but the rate of improvement slowed significantly) and that sitting or sitting with some walking led to more benefits , whereas other activities did not influence the cortisol response.

This may sound intuitive, but how many of you get out into nature on a regular basis? As our lifestyles have become more urban, many of us have lost our connection with the outdoors. What this study suggests is that it’s time for doctors to start prescribing the “Nature Pill,” instructing patients to spend a minimum of twenty to thirty minutes in nature at least three times per week.

Does the Microbiome Explain the Benefits of Nature?

There are a lot of theories about why nature benefits our health so much. In fact, one study explains that there are more than two dozen plausible mechanisms behind the benefits of nature, and it’s likely all of them are playing a role in nature’s benefits simultaneously.

• Phytoncides (these are essentially the natural essential oils found in nature) 
• Negative air ions (responsible for that “clean air” feeling in nature) 
• The soilbiome (a diverse range of bacteria that live in the soil, and help increase our own microbiome’s diversity )
• Natural sights and sounds
• Less air pollution 
• Less heat (it’s always cooler in a forest)
• Less violence

As America’s Gut Doctor, and someone who is consistently spreading the word about the importance of the gut microbiome and how it influences overall health, you know I have to hone in on the third item in that list.

So, can the bacteria found in nature explain some of its benefits? The answer seems to be yes! Nature exposes us to a wide range of beneficial bacteria that we wouldn’t necessarily be exposed to in our indoor environments or city dweller routines. In fact, a study published in Nature a few years ago dove into this exact connection.

The researchers set out to explore whether outdoor activities could enhance the general well-being of children, so they recruited 54 children to participate in a 10-week nature exposure program, and measured the effect on their health and well-being. What’s really interesting to me is that they tested their fecal serotonin levels ( serotonin is your “happiness molecule” that controls your mood) and gut microbiome profiles before and after the 10-week program, and results showed that their fecal serotonin levels increased and their gut microbiota was significantly altered by the end of the program, with the most noticeable change being an increase in the abundance of a type of bacteria called Roseburia . As a result, overall perceived stress and the frequency of anger dropped in these children.

Knowing all this, it’s not much of a leap at all to wonder if the lack of exposure to diverse microbes in modern urban societies is putting us at risk for mental health issues, like anxiety and depression, and contributing to chronic stress.

HAPPY GUT® Restore: A Daily Dose of Nature

I frequently encourage my patients to spend more time in nature not only to reap the benefits of stress reduction, but to expose themselves to a wide range of healthy bacteria. And thanks to this study , we know that at least 20 minutes a few times a week will do the trick!

If you want to further optimize your exposure to a health-promoting probiotic bacteria to support healthy stress levels and your mental and physical health, a daily probiotic supplement is the perfect way to do that. My HAPPY GUT® Restore probiotic contains 10 highly-researched probiotic strains to support microbial diversity. It’s the perfect way to inoculate the gut with a diverse range of healthy bacteria to reverse the effects of antibiotics, pesticides, diets high in sugars and refined carbohydrates, stress, and of course, lack of exposure to green space and nature in our modern lives. Combine both, and you’re giving your brain and body a huge boost of benefits.