A couple of weeks ago, I presented at the Ontario Forestry Association’s Annual Conference. This year’s theme was “Prescription for Nature: Healthy Forests for Healthy People”. It was an inspiring conference, with great speakers from the Back to Nature Network, Tree Canada, and the Kinark Outdoor Centre amongst others. I was asked to speak from a clinical perspective about the relationship between forests and human health, a topic I am very passionate about, as it speaks to the vis medicatrix naturae, or the healing power of nature. It was also a pleasure to present to a different audience than the usual naturopathic students I lecture to on a weekly basis.
A defining principle of naturopathic medicine is the notion of the vis medicatrix naturae. This vitalistic concept, which dates back to Hippocrates, argues that there is an inherent and ordered tendency in nature towards balance, homeodynamism, and thus the restoration of health — health of the individual, health of the ecosystem, and health of the planet. Implicit in this idea, is that there is a self-organizing and self-healing force that exists both within individual living things but also between them, where the whole system is greater than the sum of its parts and the vis is understood to be an emergent property, increasing in complexity at each level of being.
Presented in sometimes very different words, similar core values regarding humans’ relationship to nature can be seen in cultural, spiritual and religious traditions around the world. This drive toward connecting with nature has also been described by biologist Edward O. Wilson as biophilia, the idea that an instinctive bond exists between humans and other living systems. We can see it again echoed in the cultural practices of friluftsliv, the Scandinavian philosophy of open air living, and in shinrin-yoku, Japanese forest bathing.
Intrinsically, most people know that they feel better in a natural setting, whether that’s in the woods, on the beach, or on a mountaintop. That’s why so many people gravitate to nature to relax and take a break from their daily routine. Even still, many people find it difficult to find the motivation, time and resources to get outside. In Richard Louv’s words, many of us are suffering from “nature deficit disorder”. Thankfully, for those who want scientific evidence to prove the importance of taking a walk in the woods, many studies have been conducted showing how contact with nature is beneficial to health, even in the absence of exercise.
In numerous studies, forest bathing resulted in reductions in pulse, blood pressure, heart rate variability, and cortisol levels; it increased the number of natural killer cells and other intracellular anti-cancer activity; and it improved insulin sensitivity, decreased blood glucose, and hemoglobin A1C in diabetics. Even just looking at photographs of natural landscapes correlated to reduced sensation of pain during painful procedures such as biopsies. In children, time spent in unstructured natural settings has been linked to less severe ADHD (attention deficit hyperactivity disorder) symptoms, better focus and concentration, improved asthma, increased self-esteem, reduction in near-sightedness, lower risk of obesity, decreased fears, and better social relationships with peers. Many of these health benefits persisted for over a week afterwards, suggesting that even infrequent time in nature has potentially significant health benefits.
Some healthcare providers and organizations have looked at the available research and responded by introducing “green prescriptions”, prescribing more outdoor time in nature as part of an overall treatment plan or wellness approach. Spending time in nature is something that I often suggest to patients in my clinical practice for loads of different reasons and in many different ways: walking, hiking, biking, contemplating, meditating, gardening, bird watching, canoeing, or just plain being in nature.
While Japanese researchers theorize that the essential oils, or phytoncides, in the forest air are responsible for many of the health benefits associated with forest bathing, I believe that phytoncides (and sunlight and vitamin D and oxygen…) only tell part of the story. There is something more going on in our time spent outdoors — a sense of groundedness and interconnectedness that results from an attunement to the rhythm of nature, and an awakening of the vis medicatrix naturae in each of us.
Although we don’t have all the words or tools to explain our connections, we understand instinctively that our health, from the biopsychosocial to the spiritual, is a reflection of the health of the Earth. If we accept that human health and planetary health are one, then our moral and social obligations to restore a healthy and healing connection to our environment become imperative; they challenge us to rethink many of the ways in which we live, eat, work, and play. In so doing, we can foster and renew a mutually respectful relationship with nature. As nature heals us, we, in turn, can nurture and heal the planet; we can begin to truly appreciate the healing power of nature.