Jenna Ladd | August 9, 2016
A recent study published in the New England Journal of Medicine suggests that a less dusty house is not always a healthier house.
A multidisciplinary team of researchers from several universities, including CGRER member and professor and head of the University of Iowa Department of Occupational and Environmental Health, Dr. Peter Thorne, found that particular characteristics of the Amish household bolster children’s immune systems and prevent asthma.
Researchers began with comparing two seemingly similar communities, the Amish of Indiana and the Hutterites in South Dakota. Even though the two groups share comparable genetic backgrounds, diets, and lifestyles, a compelling difference in the number of asthmatic children was found. About 21% of Hutterite children aged 6-14 have asthma while only 5% of Amish children, about half the national average, have been diagnosed. Scientists posit that one major difference between the communities accounts for this trend: farming practices.
Hutterite communities operate large, industrialized farms that utilize electricity. Dairy barns are often located a distance away from family homes and children do not play in them. In contrast, the Amish keep single-family, electricity-free dairy farms. Horses are used to power the farms and for transportation. Dairy barns are often located near the family home and are an acceptable play area for children.
The scientists began with a modest study, comparing immune cells found in blood samples from 30 Amish and 30 Hutterite children, all aged 7-14. All 30 of the Amish children were found to have high counts of neutrophils, or white blood cells that act as the body’s “innate immune system.” None of the Amish were found to have asthma. In contrast, 6 of the Hutterite children had an asthma diagnosis and all of them had considerably lower levels of neutrophils in the blood.
Researchers also placed Electrostatic Dust Samplers inside the homes the Amish and Hutterite children to measure toxins and airborne particulates. The electricity-free samplers found that Amish house dust was “much richer in microbial products” from farm animals that are carried into the home. The microbial life found inside the Amish children’s homes explains their spiked neutrophil levels that prevent asthma.
The team was able to corroborate the results in animals, Thorne explains, “When we administered extracts of the two types of dust to mice, we were able to reproduce the differences in respiratory allergy that we observed in the Amish and Hutterite children.”
Dr. Talal Chatila a Harvard Medical School immunologist who wrote an editorial published along with the report said, “it is not far-fetched to start thinking of how one could harness those bacteria for a therapeutic intervention.”
The team also included researchers from the University of Chicago, the University of Arizona, Dr. von Hauner Children Hospital in Munich, Germany, and Allergy and Asthma Consultants, Indianapolis.