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A new federal report provides proof that more American children are suffering from food allergies.
Scientists don't know for sure what's behind this jump, but not playing in the dirt could be playing a dirty trick on your child's immune system.
New research from the Centers for Disease Control (CDC) finds childhood food allergies jumped 18 percent in the past decade.
"I see many more children with food allergies," said Dr. Paul Ehrlich.
The evidence also shows children with food allergies are more likely to have asthma and other allergic diseases
"We don't know why there are more allergies and asthma, but there are some really interesting theories," said Dr. Homer Boushey, of the University of California-San Francisco.
Boushey points to what's called the "hygiene hypothesis."
"Which, in its simplest terms, says the rise in allergies and asthma is the unintended consequence of modern hygiene," he explained.
In other words, a consequence of being a little too clean around young infants.
Researchers studied kids who grew up on farms around animals. "The more contact among animals, the lower the rates of allergy and asthma. We're wondering if there is something about manure," Boushey said.
Industrialized nations may be at greater risk. After the fall of the Berlin Wall, researchers thought they'd uncover an epidemic of asthma and allergies in East Germany, where coal is burned and the air is choked with sulfur dioxide.
If the hygiene hypothesis plays out, children may need to play more in the dirt when they're quite young.
"I go by the old adage that a kid should eat a pound of dirt before age 5," one mother told us.
Dirt is chock full of harmless microbes, and that might just tune up a baby's developing immune system.
Researchers examined the diapers of 1,000 babies and found those babies from developed nations had an imbalance of important microbes in their gut.
Researchers are studying whether adding these microbes to an infant's diet may tune up that baby's immune system so the baby won't develop asthma, even allergies.