Want healthier children? Get some rats and cockroaches

A study out today might make roach, mouse and pet droppings in your home the new health aids.

The study, from Johns Hopkins, found that 41 percent of allergy-free and wheeze-free children in the study “grew up in homes that were rich with allergens and bacteria.” It stunned researchers who expected to find just the opposite. But only 8 percent of children who suffered from both allergy and wheezing had been exposed to these substances in their first year of life, researchers said.

The findings support the “hygiene hypothesis,” which holds that children in overly clean houses are more apt to suffer allergies because their bodies don’t have the opportunity to develop appropriate responses to allergens, said Dr. Todd Mahr, an allergist-immunologist in La Crosse, Wis., and chair of the American Academy of Pediatrics’ Section on Allergy & Immunology.

Prior research has shown that children who grow up on farms have lower allergy and asthma rates, possibly due to their regular exposure to bacteria and microbes, the researchers noted in background material.

“The environment appears to play a role, and if you have too clean of an environment the child’s immune system is not going to be stimulated,” Mahr explained.

As many as half of all 3-year-olds in the United States suffer from wheezing illnesses, and recurrent wheezing and allergies are considered a risk factor for asthma in later life, researchers said. According to the American Lung Association, asthma remains one of the most common pediatric illnesses, affecting about 7 million American children.

The study found that infants who grew up in homes with mouse and cat dander and cockroach droppings in the first year of life had lower rates of wheezing at age 3.