"In every walk with nature one receives far more than he seeks." –John Muir
John Muir, the well known outdoorsman and naturalist, well known enough that he has a wilderness area named after him in California, knew what he was talking about. Muir seemed to be seeking solace, peace, inspiration, and wonder, as well as a good ol’ fashioned work out, when he stepped out into Nature. And he didn’t just go for little day jaunts. He would set out with minimal gear for days at a time, crossing landscapes that didn’t have actual trails through them. Yet. You can learn more about Muir here.
Traditional wisdom is the wisdom that’s been passed down through the generations, not necessarily because we understood WHY it works, but because it simply DID work. I think there’s been a long standing traditional wisdom that we’re healthier when we’re outside. Not that it’s always sunshine and roses, but that we’re better off when we interact with the natural elements on a regular basis (so long as we survive the encounter). I’m absolutely not romanticizing our relationship with Nature here. Nature doesn’t care about us one way or the other. If anything, Nature serves as a weeding-out force. Only the good enough (or extremely lucky, and that only lasts so long) survive. But it wasn’t until fairly recently that humans developed the technology to separate ourselves from the daily and seasonal rhythms and pressures of Nature. Up until then, our species was being sculpted and refined by natural forces no less than the plants and animals that we were struggling to survive with. Those of us who are alive today are the descendants of those who survived. Take a moment to really think about that. Your ancestors were good enough to survive the trials that Nature executed, the wheat separated from the chaff.
So, it wouldn’t be hard to infer that if we are the descendants of survivors, it’s likely that our ancestors had adaptations, maybe just minor alterations in their anatomy and physiology, that made them better suited to those natural elements, that maybe they even had traits that enhanced their well being BECAUSE of some interaction with Nature. And that those individuals who weren’t able to turn their exposure to Nature into a benefit, didn’t thrive as much. So perhaps our ancestors didn’t survive in spite of natural forces but because of them. Could that be another way to interpret Muir’s quote at the beginning of this piece?
Take a moment to really think about that. Your ancestors were good enough to survive the trials that Nature executed, the wheat separated from the chaff.
One of the pitfalls of a scientifically literate (or maybe just scientifically aware) populace is we believe we need evidence, data, proof before we can accept something as true. John Muir didn’t need science to tell him that Nature was good for him; he literally felt it in his bones and in his spirit. Nowadays we call that “anecdotal” and that’s taken on an almost negative connotation. Today, if someone asks you why they should leave their climate controlled, cushy, safe, well lit, air conditioned, and pest-free indoor space, your argument may fall flat if you just say, “Because John Muir said so.”
But you know what’s great? All that traditional wisdom that was blindly (and correctly) accepted for so long, now has some modern scientific teeth to it. It just took awhile to develop the tech to find it. Keep reading to see some of the ways that we benefit from spending time in Nature. Fair warning, I tend to geek out over stuff like this so if that’s not your cup of tea, no judgement, but it’s about to get sciencey!
The source referenced here is “The Nature Fix: Why Nature Makes Us Happier, Healthier, and More Creative” by Florence Williams. I also highly recommend “The Biophilia Effect: A Scientific and Spiritual Exploration of the Healing Bond Between Human and Nature” by Clemens G. Arvay.
1. Decreased “fight-or-flight” mode
Your nervous system has two basic modes: fight-or-flight (sometimes a third “f” is added — freeze) and rest-and-digest. Your fight-or-flight (FoF) mode is controlled by the sympathetic nervous system and your rest-and-digest (RaD) mode is controlled by the parasympathetic nervous system.
FoF is critical for our survival. It allows us to respond to acute and immediate times of danger or uncertainty. Our blood pressure ramps up to improve circulation to critical structures like your muscles, your senses become heightened, your pulse increases to support rapid oxygenation for whatever action you have to take. Adrenaline reduces your sensitivity to pain and might even change your perception of time (possibly by speeding up the rate at which your neurons send signals). In the short term, these changes can be the difference between life and death. Cortisol, the other stress-related hormone that often gets a bad rap, can also be released to help your body deal with long-term, chronic stress.
But if this mode is allowed to stay in charge for too long, the body loses its ability to maintain homeostasis. FoF also shuts down your digestive functions because the gut requires a large amount of blood to function. You only have so much blood and if it’s being routed to your muscles and nervous system, there’s not a lot left over for digesting. No digestion means no nutrients are being distributed to those very cells that are literally burning through their resources at a faster rate. So FoF may allow you win the battle, but if it never cedes control to the RaD mode, your body will ultimately lose the war. Rest-and-Digest is ultimately where you want your body to spend most of its time, and there’s something about Nature that triggers that change (assuming you’re not being chased by a mountain lion or tumbling down a hill, of course). Oddly, even just pictures of calm nature scenes can be enough to turn RaD back on (Williams, pg. 26).
Blood pressure drops (sometimes as much as 5-7%) (Williams, pg. 63), cortisol levels decrease, heart rate and respirations slow, your brain waves change, and food tastes better (Williams, pg. 25). I guess that’s why I loved Dinty Moore stew while camping but wouldn’t touch the stuff at home.
Take away: If you suffer from chronic stress, assess how much time you spend outside versus how much exposure you have to “urban” stimuli. Even something as simple as a patio garden or a community park could be enough to give permission for your rest-and-digest mode to take back the reins.
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2. Enhanced immune system
It is possible for your immune system to be too “enhanced” (just ask anyone with an autoimmune disorder), so we want to be careful about making it seem like strengthening one’s immune system is all good with no consequences. However, there are some aspects of your immune system that are positively affected by Nature and that are not as likely to cause downstream problems.
The highly specialized fighters in the immune system often get a lot of the attention. Your B-cells, or antibody-forming cells, and T-cells, or foreign body assassins, seek out and destroy specific bad guys. These are the ones that we can train through vaccinations or environmental exposure to antigens. But our immune system also has more generalized protective cells that roam through the body like an everyday security force. One example of these are Natural Killer (NK) cells. They look for cells that have been turned to the dark side, thanks to a virus or cancerous mutation. When an NK cell finds a “bad” cell, they destroy it before it can do more harm. (Looking for a deeper dive on the immune system? You got it.)
So it would seem like if you’re trying to reduce your risk of suffering from a virus or developing cancer, you might be curious how to increase your circulating NK cells, huh? Don’t worry, Nature’s got your back… and your front… and your insides. And it gets to you through your nose, at least that what some studies out of Korea seem to be showing (Williams, pg 62). The smells of pine trees and even the forest soil after it rains seem to be particularly potent triggers of NK cells (and the parasympathetic nervous system - see the first item in this list). In one lab study, subjects were exposed to the smell of cypress trees while they slept. Their NK cells increase by 20% compared to the control group (no cypress smell while they slept) (Williams, pg 29).
In another study, people were asked to hike for a couple hours each day for three days. After those three days, their NK cells increased 40% relative to their pre-hike levels (Williams, pg. 28). The researchers also found that increase was sustained for a week after the last hike, and to a lesser effect, a month after the last hike. Similar walks through a city environment did not affect the NK cells. So it wasn’t just the physicality of the hike that increased the NK cells. There was something about the type of environment! As with all complex systems, there’s likely way more going on here than we currently realize but it’s still so fascinating that our bodies physiologically respond to the sensory stimulation from Nature.
Another bonus is if you get outside when you’re young, your immune system will likely be better trained to recognize friend from foe because of the immense exposure it will get to a wide variety of potential antigens, which could lead to a lower risk for allergies. There’s way more to this particular story, like genetics and whether you were breast fed or not, but it certainly couldn’t hurt to get kids outside more, right??
Take Away: If you want a cheap way to boost your body’s basic immune function, get outside. Smell the trees, touch the soil, listen to water and birdsong and the wind in the leaves. Your Natural Killer cells like it, but those virus-infected and pre-cancerous cells don’t!
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3. Increased mental health and creativity
I always knew I was happier in Nature. I also did some of my best writing there. I just figured that was my personality, but it turns out human brains are wired to respond to Nature. I guess I’m not special after all…
The mind and body are inextricably linked. They affect each other, for better or worse. Physiological stress can certainly affect your mental state (and your mental state can certainly affect your physical body), and we’ve already established that natural stimuli can reduce physiological stress. So perhaps Nature is assisting your mental health by just reducing stress. Or maybe it’s just because you’re out of your normal elements, away from the stimuli that would normally remind you of your responsibilities (dishes and laundry, I’m looking at you!). Or, perhaps, there are other interactions at work. There’s still a lot of research going on here because understanding how the brain works is very much a work-in-progress. But given the rates of mental health decline in modern society, and the profits pharmaceutical companies are making off that decline, wouldn’t it be nice if we could mitigate some of those issues be just getting outside?
In one lab study, subjects’ brain waves were measured when they looked at nature scenes versus pictures of human architecture. Nature scenes elicited a brain activity pattern known as alpha waves, which indicate relaxation and are also correlated with higher serotonin levels (happy brain hormones). The architecture scenes did not have this result on the brain (Williams, pg. 26).
In another study, subjects were asked to find the association between three seemingly unrelated words. After spending several days in nature as part of a structured outdoors experience, their ability to find the associations between the sets of words improved by 50% (Williams, pg. 37). Can you say, “Solution to writer’s block.”?
Williams explores several possible mechanisms for how Nature affects us. One is the speed at which we move through Nature versus our normal day-to-day life. We evolved to move at the speed of Nature, but modern life seems to be go! go! go! and we find ourselves overbooked and rushing from one obligation to another. Being in Nature gives us the freedom to slow back down, to move at the speed we evolved at without the novel stimulations of modern life. Another is what part of the brain we activate when we’re in Nature. The pre-frontal cortex is unique to mammals and particularly well-developed in humans. It’s what allows us abstract thought and higher-order thinking (think: executive function). It’s also what allows us to perseverate on unproductive thought spirals. Being in Nature seems to quiet or deprioritize this part of the brain and amplify the parts that focus on spatial and sensory input as well as unstructured thought (aka: daydreaming). Our brains become more “present” and attuned to the now (Williams, pg 48).
Take Away: If you need a mental refresh, either to give your unproductive thoughts a break or to inspire new ideas, go outside - or at the very least look at nature pictures and listen to nature sounds (did I mention that I publish soundscapes like the one below in my Substack…?). Your brain waves will thank you with increased serotonin and dopamine. And if you happen to get a little exercise in with a hike, all the better!
This list is just the tip of the pine tree (I’m partial to forests, what can I say?). I highly encourage you to explore this topic in more detail by either checking out the two books I mentioned above or doing your own research, preferably while sitting outside.
So make like John Muir and go for a walk. Regardless of what you seek along the way, you will receive a more rested nervous system, a more effective immune system, and a better state of mind. Oh, and another thing, you’ll sleep better! Trust me. What could it hurt? I mean, so long as you don’t actually get stung by a bee or hit by lighting or trip on a rock or… well, I should probably stop before I talk you out of it, huh?
Did any of these benefits surprise you? Or do you have other arguments for why we should get outside more often? Let us know in the comments by clicking the link below.