Kathmandu, September 10 – Many people are aware of the visual and auditory pleasures derived from spending time outdoors in nature. However, recent research has unveiled significant findings regarding the impact of directly touching soil, plants, and trees on human health. A scientific study conducted in Finland reveals that direct contact with soil and natural vegetation increases the diversity of microbes residing on the skin, thereby strengthening the immune system.
In an experiment led by ecologist and nature-health researcher Miira Grönroos from the Finnish Environment Institute, participants applied soil and peat moss to their hands for 20 seconds. Even after washing their hands with water, there was a notable increase in both the number and diversity of beneficial bacteria on their skin.
Scientists explain that a balanced mixture of bacteria on the skin helps inhibit the spread of harmful pathogens. Similarly, a two-year study involving Finnish children, led by environmental expert Marja Roslund, yielded comparable results. Children who regularly played in natural environments such as soil and shrubbery-covered yards exhibited greater microbial diversity on their skin after one year compared to those who played in paved or cemented areas.
The research further indicates that an increase in the diversity of certain bacteria, particularly Gammaproteobacteria, correlates with elevated levels of regulatory T cells (a type of white blood cell), which effectively modulate the immune system and reduce the risk of autoimmune diseases.
These benefits of natural contact are not limited to children; studies have confirmed similar effects in adults as well. In one study, adults who grew vegetables indoors during winter using organic soil showed increased bacterial diversity on their skin and higher levels of anti-inflammatory cytokines in their blood, which reduce inflammation. Additionally, research demonstrates that integrating living plants such as “green walls” into office spaces improves employees’ skin health and lowers inflammatory markers in their bloodstream.
Researchers assert that these findings reinforce the “biodiversity hypothesis,” which suggests that a lack of environmental biodiversity has contributed to a rise in immune-related health issues in recent times. Small habits like touching tree bark, sitting on grass, and having direct contact with soil in daily life may have long-term positive effects on health.
