Could you be allergic to the United States? A new study released Monday said that children born in the US or raised here are more likely to develop allergies, eczema, hay fever, and asthma compared to children born in other countries.
The study, published in the journal JAMA Pediatrics, was based on information from 91,800 U.S. children whose parents participated in a between 2007 and 2008. According to the findings, that just over 20 percent of children born outside the U.S. had some form of allergy compared to 35 percent of children born within the country. Children born outside the United States were 73 percent less likely to have asthma, 55 percent less likely to have eczema and 66 percent less likely to have hay fever.
Meanwhile, children who immigrated to the United States were about 44 percent less likely to have an allergy condition compared with children born in the country. However, the protection against allergies wore off after the child lived over 10 years in the U.S. Children who were born in the United States but whose parents were immigrants also had a reduced risk of allergies.
"The findings of the present study are consistent with the broader hygiene hypothesis, which suggests that either infections or certain microbial exposures in early childhood may confer protection against [allergies and asthma]," said study researcher Dr. Jonathan Silverberg, a dermatologist at St. Luke's-Roosevelt Hospital Center in New York City.
Without exposure to germs, the immune system has shifted away from fighting infection to developing more allergic tendencies. More than half of Americans ages 6 to 59 years are sensitive to at least one allergen, according to the National Institutes of Health.
