A study finds that children who are exposed to higher concentrations of cats, cockroaches and mouse allergens during infancy are less likely to develop asthma by the age of 7.
The findings, published in the Journal of Allergy and Clinical Immunology on Sept.19, suggest that early life allergen exposure may have a preventive effect on children who were at a high risk of developing asthma.
“If we can develop strategies to prevent asthma before it develops, we will help alleviate the burden this disease places on millions of people, as well as on their families and communities,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), which funded the research. An estimated 6.2 million U.S. children have asthma.
The research is part of an ongoing Urban Environment and Childhood (URECA) study that has been following 560 newborns in four U.S. inner cities (Boston, New York City, St. Louis and Baltimore) since 2005. The children have a family history of asthma or allergies. Of 442 children in the study, 130 – 29 percent – had asthma by age 7.
Dust samples were collected from the children’s homes when they were 3 months old, and then at the ages of 2 and 3 years old. The dust samples that contained a higher concentration of cockroach, mouse and cat allergens were linked to a lower chance of developing asthma by the age of 7. Dog allergen was also associated with the research, although it was not “statistically significant.”
Previous studies have found that reducing pest and pet allergens in your home is helpful to disease management once a person develops asthma. But this research, led by the University of Wisconsin-Madison, is looking at asthma prevention in early life.
In the URECA study, exposure to certain bacteria in the children’s home during infancy also suggested a link to asthma, although additional research is needed.
“Our observations imply that exposure to a broad variety of indoor allergens, bacteria and bacterial products early in life may reduce the risk of developing asthma,” one of the study’s authors, Dr. James Gern, said in a press release. “Additional research may help us identify specific targets for asthma prevention strategies.”
The study is in keeping with the hygiene hypothesis, which suggests that less sterile environments in early life help with the development of immune tolerance and may prevent allergies.