Exposure to common antibacterial chemicals and preservatives found in soap, toothpaste, mouthwash and other personal-care products may make children more prone to a wide range of food and environmental allergies, according to new research from Johns Hopkins Children's Center.
Results of the NIH-funded study are published online ahead of print June 18 in the Journal of Allergy and Clinical Immunology.
Using existing data from a national health survey of 860 children ages 6 to 18, Johns Hopkins researchers examined the relationship between a child's urinary levels of antibacterials and preservatives found in many personal-hygiene products and the presence of IgE antibodies in the child's blood. IgE antibodies are immune chemicals that rise in response to an allergen and are markedly elevated in people with allergies.
"We saw a link between level of exposure, measured by the amount of antimicrobial agents in the urine, and allergy risk, indicated by circulating antibodies to specific allergens," said lead investigator Jessica Savage, M.D., M.H.S., an allergy and immunology fellow at Hopkins.
The researchers caution that the findings do not demonstrate that antibacterials and preservatives themselves cause the allergies, but instead suggest that these agents play a role in immune system development.
The investigators say their findings are also consistent with the so-called hygiene hypothesis, which has recently gained traction as one possible explanation behind the growing rates of food and environmental allergies in the developed world. The hypothesis suggests that early childhood exposure to common pathogens is essential in building healthy immune responses. Lack of such exposure, according to the theory, can lead to an overactive immune system that misfires against harmless substances such as food proteins, pollen or pet dander.
"The link between allergy risk and antimicrobial exposure suggests that these agents may disrupt the delicate balance between beneficial and bad bacteria in the body and lead to immune system dysregulation, which in turn raises the risk of allergies," Savage added.