Have you ever considered why you feel more vibrant and content when walking through woods or by the sea? Is it solely because you’re unwinding from work and enjoying the scenery, or is there more to it? For over two decades, researchers have been exploring how exposure to biodiversity enhances health. Japanese scientists led this investigation on Yakushima island, renowned for its biodiversity, where they had a term for the sensation of being in nature: shinrin-yoku or “forest bathing.”
We understand that a diverse ecosystem supports a beneficial microbial community around and within us. Moreover, exposure to green spaces, even in cities, boosts physical and mental well-being. But what drives these effects? Japanese scientists theorized that inhaling forest air delivers beneficial substances. Studies have pinpointed three significant inhaled components that contribute to a sense of well-being: beneficial bacteria, plant-derived essential oils, and negatively charged ions. From birth onward, beneficial bacteria are present in our environment, especially in the air, and within our bodies. Frequent interaction with these bacteria can promote well-being, partly because gut bacteria aid in breaking down indigestible food and releasing health-boosting substances. Plants and their surface bacteria produce essential oils to deter harmful microorganisms, known as phytoncides, or “plant-derived exterminators.”
Though research on plant essential oils is nascent, one study revealed that phytoncides from Korean pine trees improved pigs’ health and gut bacteria. Despite some pseudoscientific claims about negative ion generators, evidence suggests that negative air ions can positively affect mental health. Forests and water bodies typically have higher levels of these ions, offering potential benefits when walking in such environments. As the writer Goethe observed, “Nature has neither kernel nor shell; she is everything at once.” Bacteria, essential oils, and negative ions interact and influence each other, potentially even affecting the human gut microbiome.
Feeling connected to nature or biophilia has been associated with better health, though understanding how this affinity benefits us remains complex. An often-neglected aspect is how personal connections to nature affect health, with psychologists linking nature appreciation to mental well-being. How do closer ties with nature interact with diet, the microbiome, physical activity, and other factors? Until scientists uncover more clues, including those concerning biodiversity, there are simple ways to enjoy our natural affinity, like running in parks or near water instead of indoors, or taking walks in green spaces. Evidence increasingly supports that exposing children to more green environments aids their mental and physical development.
The Children and Nature Network in the US provides valuable research and activities connecting children with nature. A World Health Organization report emphasized the importance of microbial diversity, suggesting it bridges ecology and medicine, and highlights the link between our bodies and the broader ecosystem. It’s clear that conversations about nature and human health are crucial. A recent Journal of Physiological Anthropology paper advocated for more research on biodiversity’s impact on health, especially during childhood, a crucial developmental phase.