New research from Johns Hopkins Children's Center finds that antibacterial chemicals and preservatives in soap, toothpaste, mouthwash and other personal-care products may make children more prone to food and environmental allergies
Researchers examined the relationship between the amount of antibacterials and preservatives in a child's urine and the presence of antibodies that rise in response to an allergen. Children with the highest urine levels of antibacterials had the highest levels of food allergy antibodies. Kids with the most preservatives in their urine were more likely to have antibodies to pollen and other environmental allergies.
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 dis-regulation, which in turn raises the risk of allergies," according to Jessica Savage, M.D., M.H.S., an allergy and immunology fellow at Hopkins.
To clarify the link between antimicrobial agents and allergy development, the researchers are planning a long-term study in babies exposed to antibacterial ingredients at birth, following them throughout childhood.