CAN A NATURAL ENVIRONMENT WARD OFF ALLERGIES?

When spring arrives, hay fever season begins. Close to 20 million Americans are affected by allergic rhinitis in any 12-month period, and some 50 million have allergies of one kind or another. But what causes them, and why does it seem more people are suffering their debilitating effects? A group of Finnish researchers investigated these questions and established a direct link between where we grow up and allergies. Because no matter where a person lives, we all harbor a multitude of microbes on our skin. Furthermore, different kinds of microorganisms accumulate on the bodies of people who live in cities as opposed to the bodies of people who reside in rural areas. “However, the microbiota in a natural environment is more beneficial for the human organism,” explained ecologist Ilkka Hanski before his death in 2016. Together with his colleagues, who have continued research in the field since his death, the Finnish scientist discovered that the dwindling biodiversity of microorganisms is particularly problematic.

“Rapidly decreasing biodiversity among microbes could lead to a global megatrend in the future: the dramatic spread of allergies as well as other chronic inflammatory diseases.” The reason for this dwindling biodiversity is heavy urbanization. For instance, people who reside in cities have considerably less gammaproteobacteria on their skin. This class of bacteria is ecologically and medically significant and plays a decisive role in modulating the immune system. As the Finnish researchers discovered, these bacteria are directly responsible for suppressing inflammatory reactions in the body to pollen or animals, for example. Thus a lack of microbial diversity results in insufficient stimulation of immunoregulatory circuits. And so the trend of more of the global population living in urban areas and having limited contact with nature could explain why chronic inflammatory disorders, which include allergies and autoimmune diseases, appear to be on the rise—all the more reason to get back to nature whenever possible.