From Our 2012 Archives
Farm Life Linked to Fewer Allergies, Less Asthma
Study: Amish Farm Children Have Lower Rates of Hay Fever
By Charlene Laino
Reviewed by Laura J. Martin, MD
March 7, 2012 (Orlando, Fla.) -- Could the older, more rustic Amish lifestyle hold the key to preventing allergies?
An Indiana researcher thinks so. His research suggests that children who grow up on Amish farms are less prone to allergies and hay fever than Swiss youngsters who are raised on more modern-day farms.
"And kids who live in either farming environment have much lower rates of allergies and asthma than children who don't grow up on farms," says Mark Holbreich, MD, of Allergy and Asthma Consultants in Indianapolis.
The research adds support to the so-called hygiene hypothesis -- the idea that a too-clean world is to blame for rising rates of allergies.
As our homes and public spaces have become cleaner, the theory goes, young children are being exposed to fewer germs, infectious agents, and other substances that help train their developing immune systems to recognize and fight allergic disease.
"The Amish live a 19th century lifestyle, spending time in the barn, drinking milk directly from the cow, all the things that used to expose us to these substances early in life," Holbreich tells WebMD.
Allergies on Rise
An estimated 50 million Americans suffer from allergies, and allergy rates have been increasing since the early 1980s across all age and racial groups, according to the Asthma and Allergy Foundation of America.
The new study involved 157 Amish children in the U.S., more than 3,000 Swiss farm children, and nearly 11,000 Swiss children who did not live on farms.
The researchers chose to compare Amish children to Swiss children because many Amish people emigrated from Switzerland to the U.S. in the 1800s.
Only 5% of the Amish children had ever received a diagnosis of asthma, and only one (0.6%) had been diagnosed with hay fever at some point in their life.
Among the Swiss farm children, 7% had been diagnosed with asthma, and 3% with hay fever.
In contrast, 11% of the non-farm-dwelling Swiss children had ever been diagnosed with asthma, and 12% had ever been diagnosed with hay fever.
When it came to testing positive on skin or blood tests for dust mites, ragweed, or other allergens, the differences were more dramatic, Holbreich says. A total of 44% and 25% of the Swiss non-farm and farm kids, respectively, showed sensitivity to allergens, vs. only 7% of the Amish farm kids.
The findings were presented here at the annual meeting of the American Academy of Allergy, Asthma & Immunology.
Raw Milk Protective?
So what is it about the Amish lifestyle that protects against allergies? Holbreich says previous research points to two factors. One is being around large barn animals from a young age, he says. The other: drinking raw, unpasteurized milk directly from the cow.
"We think that when milk is homogenized, it breaks up fat molecules that have an impact on the developing immune system to make kids less prone to all allergies," he says.
But don't start giving your child raw milk, as it can harbor disease-causing bacteria, Holbreich cautions.
"The hope is that we can isolate the protective factor in raw milk and develop an infant formula to prevent allergies," he says.
Jessica Savage, MD, MHS, of Johns Hopkins Hospital in Baltimore, agrees that the work appears to support the hygiene hypothesis. "But this is all still very preliminary," she tells WebMD.
These findings were presented at a medical conference. They should be considered preliminary, as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
SOURCES: 2012 Annual Meeting of the American Academy of Allergy, Asthma & Immunology, Orlando, Fla., March 2-6, 2012.Mark Holbreich, MD, Allergy and Asthma Consultants, Indianapolis, Ind.Jessica Savage, MD, MHS, clinical fellow, allergy & immunology, Johns Hopkins Hospital, Baltimore, Md.
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