Does Having Pets Reduce Children's Risk of Developing Allergies?
Though children with asthma are usually advised to avoid allergens that could exacerbate their symptoms, new research published in the Journal of Allergy and Clinical Immunology suggests that exposure to allergens associated with pets - and even pests - can actually prevent the development of asthma.
Dr. James Gern from the University of Wisconsin-Madison led this new study as part of an ongoing Urban Environment and Childhood Asthma study. For this particular study, Dr. Gern and his team studied 560 children living in New York City, Boston, St. Louis, and Baltimore, beginning in 2005. The children who were studied were considered at risk for developing asthma because each child had at least one parent with asthma or allergies.
When the children were aged 3 months, 2 years, and 3 years, researchers sampled allergens from their homes. They also tracked the children to determine their incidence of asthma over the first 7 years of the children's lives. They found that the higher the concentration of cockroach, mouse, and cat allergens present in these children's homes, the lower the children's risk of developing asthma by the age of 7.
Though dog allergens alone did not seem to confer any preventative benefit, when dog allergens were combined with these other allergens, the risk for developing asthma was even lower than when just cockroach, mouse, and cat allergens were present. Cockroaches appeared to be the most powerful in staving off the development of asthma.
These findings are consistent with other data suggesting that exposure to allergens can prevent the development of asthma and allergies by training the immune system to recognize these substances as harmless. These results also point to the possibility of new preventative measures for asthma. For instance, if specific allergens or bacteria can be clearly and repeatedly shown to reduce asthma risk, this knowledge can be used in the development of interventions to reduce the chances that children get the disease.