Exposure to dairy farms early in life may dramatically reduce the frequency and severity of respiratory illnesses, allergies and chronic skin rashes among young children according to collaborative research involving the University of Wisconsin School of Medicine and Public Health, and the National Farm Medicine Center (NFMC) at Marshfield Clinic Research Institute (MCRI).

Results published online Sept. 1 in the Journal of Allergy and Clinical Immunology are the first data to show an association between farm exposure and a reduction in respiratory illnesses requiring medical attention. (Click to read accepted manuscript.)

The study was conducted in the Marshfield Epidemiologic Study Area (MESA). It compared 268 children ages 5 to 17 who lived on a dairy farm from birth to five years to 247 children who live in a rural area but never lived on a farm. The study included the use of questionnaires and review of electronic medical records.

“Seeing decreased allergies in farm-exposed children from the Marshfield area is in agreement with similar findings in Western Europe that found farm exposure is linked to allergic disease and wheezing illnesses,” said Christine Seroogy, M.D., UW associate professor of pediatrics.

Exactly how farm exposure reduces childhood respiratory illnesses is the focus of a related study, the Wisconsin Infant Study Cohort (WISC) project. UW researchers are working with NFMC Associate Research Scientist Casper Bendixsen, Ph.D., and the MCRI-based team, which includes staff from the Farm Center, Center for Clinical Epidemiology and Population Health, Integrated Research and Development Laboratory, and Biomedical Informatics Research Center.

“The WISC collaboration is indicative of how multidisciplinary our work can be,” Dr. Bendixsen said. “It also shows how critical our farm population is to medical research. While the majority of NFMC’s work focuses on the hazards of agricultural work, this study examines the health-promoting aspects of the farming lifestyle.”

Dr. Seroogy and UW co-investigator James Gern, M.D., professor of pediatrics, said the first two years of life are the most important for immune system development. The WISC pilot phase, begun in 2013, compared immune responses in the cord blood from healthy babies born into farming environments and cord blood from healthy infants born into non-farming environments. WISC continued with the enrollment of 200 babies from the Marshfield area — half from farms, and the other half from rural non-farm homes. Prospective study participants were identified through the Marshfield Clinic electronic medical record. For two years, starting in the womb, researchers are tracking the children’s exposure to farm animals and farm-related microbes. They are measuring the development of cells involved in immunity and resistance to viral respiratory illnesses, and also tracking respiratory infections and development of allergies.

The WISC study is scheduled to conclude in 2018.

Co-authors on the recent publication include former National Farm Medicine Center Medical Director Steven Kirkhorn, M.D.; former NFMC Director Matthew Keifer, M.D; and former MCRI epidemiologist Stephen Waring, Ph.D.