The study was funded by the NIH and was conducted by researchers at Johns Hopkins. They used data from a national health survey of 860 kids between 6 and 18. They looked at the connection between the levels of antibacterials and preservatives found in the children’s urine and the presence of IgE antibodies in their blood. IgE antibodies are chemicals your body produces in response to allergens, and they become noticeably elevated in people who have allergies.
What they found was that kids who had had high levels of antimicrobial agents in their urine also had high levels of IgE antibodies. They were looking at seven different ingredients that have previously been shown to interfere with endocrine function in animals—bisphenol A (the newest scourge in plastics); triclosan; benzophenone-3; and propyl, methyl, butyl and ethyl parabens, which are found in lots of personal-care products and also in some foods and medications. In the end, they found that it was triclosan and both propyl and butyl parabens that were associated with higher allergy risk. What do all three of them have in common? Bingo: they’re all antimicrobial.