Day care attendance early in life seems to protect infants and young children from later developing asthma, from the Journal of Allergy and Clinical Immunology (JACI). In this study, Influence of early day care exposure on total IgE levels through age 3 years,
Janet Rothers, MS, and colleagues examined the relationship between the age at which day care attendance begins and the amount of immunoglobulin E (IgE) in a childs blood. IgE is an antibody produced by the immune system and an indicator of allergic sensitivity.
The researchers discovered that:
Children who went to day care by 3 months of age had lowered IgE levels. The IgE levels of day care children remained low through age 3 years, but this protection appeared to be limited to children whose mothers have asthma or a family history of susceptibility to allergy.
Children who attended day care outside their own home had lower IgE levels than those who attended day care in their own home with children not their siblings, or than children who didnt attend day care.
The authors speculate that regular exposure to bacteria from two different environments may play a role in immune development and supports the idea that there may be a critically short period when such bacterial exposure can guide the immature immune system to develop on a healthy path.