By Dr. Paul Ehrlich
In March, I wrote about a New England Journal of Medicine article that showed a correlation between children growing up on German farms and a lower incidence of asthma than city kids. I wrote that this seemed to confirm aspects of the Hygiene Hypothesis, but that the popular press made too much of it. I also said that farming practices in different places might produce different results.
Little did I know that I would only have to wait till August to get my contrary data. An abstract just turned up on the website of the Journal of Allergy and Clinical Immunology entitled “Rising prevalence of asthma is sex-specific in a US farming population.” It recounts “population-based studies of asthma and atopy in the Hutterites of South Dakota, a communal farming population, to assess temporal trends in asthma and atopy prevalence and describe the risk factors for asthma.”
Don’t know who the Hutterites are? Neither did I, but here is some of what I found on Wikipedia:
“Hutterites (German: Hutterer) are a communal branch of Anabaptists who, like the Amish and Mennonites, trace their roots to the Radical Reformation of the 16th century. Since the death of their founder Jakob Hutter in 1536, the beliefs of the Hutterites, especially living in a community of goods and absolute pacifism, have resulted in hundreds of years of odyssey through many countries. Nearly extinct by the 18th and 19th centuries, the Hutterites found a new home in North America. Over 125 years their population grew from 400 to around 42,000…
“Hutterite colonies often own large tracts of land and, since they function as a collective unit, can afford top-of-the-line farm implements. Some also run industrial hog, dairy, turkey, chicken, and egg production operations.”
What were the study’s conclusions?
“Asthma has increased over a 10- to 13-year period among Hutterite females and atopy [allergy] has become a significant risk factor for asthma, suggesting a change in environmental exposures that are either sex limited or that elicit a sex-specific response.”
My purpose in writing this is not to say, “I told you so.” Rather, it is to underscore my original premise. Namely, that we can’t draw sweeping conclusions on the basis of a single set of data. Asthma is a complex set of symptoms, a “syndrome” not a single disease. In our book we quote a pulmonologist named Dr. Anthony Gagliardi who said, “the study of asthma is the study of one.” That is, there are so many triggers and so many symptoms involved in asthma that you have to look at each patient as an individual. The Hutterite research has produced some fascinating variables, not least of which is that women are at risk but not men. It may be that the Hutterites have readily adopted modern farming technology even as they have preserved their old ways in other respects, resulting in crucial changes to their environment. In the meantime, none of the research will result in breakthrough prevention or treatment. We are obliged to fight asthma and allergies with the tools we have.