Like all other animals, humans gravitate towards the things, places, and features that resemble those present when we evolved. As such, we have this innate tendency to seek out natural spaces. Our bodies sense that we have a past there, and strongly prefer it to any other setting.
Evidence for this phenomenon comes in the form of preferences. Consider our relatively-slim range of preferred temperatures. Consider how, in visual spaces, we prefer to see, but not to be seen – a combination of prospecting and refuge-seeking behavior that yields, ultimately, comfort. We love Nature so much that we bring it into our homes, in the form of pets and houseplants. The omnipresence of Nature, and our careful cultivation of it, must convey some benefit. Otherwise, Evolution wouldn’t have preserved these behaviors.
Observe: the profound, untold health benefits of a simple walk in the woods.
For one, nature walks seem to have memory-promoting effects that other physical activities can’t replicate. In a study by the University of Michigan, students who walked in Nature reliably performed up to 20% better on brief visual memory tests than those who walked through the center of town. The same study was replicated for individuals with Major Depressive Disorder (Berman, Kross, et al.) and produced even more shocking results. They seemed to disproportionately benefit from Nature walks – over 53% of the sample group exhibited a significant increase in memory span after the nature walk, relative to an urban walk.
Past this single example, a meta-analysis of 10 other studies on the subject (performed by the same authors as above) showed that the mentally ill seem to benefit from disproportionally exposure to Nature. The presence of water resulted in even more substantial improvements. And while the depressed participants also showed marked increases in mood, the mood effects in Berman, Kross, et al. did not correlate with the memory effects, suggesting separate, biophysical mechanisms are at work.
An example of those biofeedback systems: Nature changes our stress response in measurable ways. Tons of researchers have observed hormonal changes brought on by Nature – with a powerful impact on the cortisol system. Study after study shows forest environments reduce cortisol, decrease heart rate, and tame blood pressure. One intensive study on 280 Japanese citizens found that forest walks resulted in a decrease of cortisol of around 15%, a reduction in heart rate of 4%, and a dip in blood pressure of about 2% for nearly all participants. Even among office workers, a window view of Nature seems to result in lower stress and higher job satisfaction.
But the benefits don’t stop there. At this point, the power Nature has over us seems to take on a supernatural tone.
Japanese traditional medicine has, for many years, considered forests to be a form of preventative medicine. “Shinrin-yoku” or “forest bathing” is a popular, oft-referred therapy for the many residents of Japan’s highly-urbanized central region. Clinical research on the practice is still in the earliest possible phases. But preliminary studies yielded such exciting outcomes, it became impossible to ignore the power of the forest.
Long-term residents of areas with greater forest coverage were found to have much lower cancer mortality rates than their urban counterparts. There are thousands of confounding factors making it difficult to establish a causal relationship – but the signs are there. When we analyze the blood of forest-dwellers, they have demonstrably higher levels of proteins known to target and kill cancer cells. They also seem to have much higher immune functioning, in general. Hopefully, in the next 5-10 years, we can discover precisely what’s causing the improvement. Until then, we should simply trust the trees. When it comes to health, it’s less important that we know how this occurs and more vital that we experience it for ourselves.
But what about city-dwellers? Are we simply supposed to accept that we might have a diminished quality of life?
The good news is: you don’t need an entire forest to reap most of these benefits. Parks convey many of the same effects – especially for nature-starved urbanites. Countless studies are proving this. Take the Dutch study Maas et al., for example. Researchers considered a sample size of over 250,000 city dwellers. They discovered that mere proximity to a green space had significant impacts on perceived general health – meaning that city dwellers feel better simply knowing they have access to natural areas.
So, the next time you’re feeling crummy, walk around some trees. That green space isn’t a luxury; it’s a necessity. And if you’re not so fortunate as to have immediate access, it’s probably closer to you than you think. Regardless, it’s always worth the journey.
You’re going home, after all.
