Too Much Hygiene? Infants in Dirty Environments Have Fewer Allergies

Keeping things too clean around the house could be making your children sick. A new study published in the Journal of Allergy and Clinical Immunology found that maintaining too high a level of hygiene and cleanliness can actually cause newborn babies, and particularly those under one year of age, to suffer from allergies and asthma later in life.

Researchers from Johns Hopkins Children’s Center in Maryland looked at 467 inner-city newborns from Baltimore, Boston, New York City and St. Louis. The babies were enrolled in the study before they were even born, and their health was monitored throughout the course of both pregnancy and birth to attain thorough data.

For the study, researchers collected allergen samples from the homes of each of the babies and measured both the amounts and types of allergens found. They then looked at incidences of allergy and asthma among the infants during their first few years of life, comparing this data to levels of exposure to potential allergens.

Upon analysis, the team observed lower rates of wheezing among children at age three who were exposed to high amounts of mouse and cat dander, as well as cockroach droppings, during their first year of life. In other words, early exposure to these allergens helped build a tolerance in the exposed children compared to those who were sheltered from the germs.