Trying to be too clean may backfire for young people’s health, according to a study that suggests chemicals from antibacterial soaps and plastics depressed the immune system and caused allergies.
Notably, the effects varied by age, Allison E. Aiello, PhD, of the University of Michigan School of Public Health in Ann Arbor, and colleagues reported online in Environmental Health Perspectives.
For those under 18, higher levels of antibacterial triclosan in the urine were linked to allergies and hay fever.
For those 18 and older, higher urinary levels of the plastic-hardening chemical bisphenol A (BPA) common in food and drink packaging were linked to higher cytomegalovirus antibody titers, suggesting a depressed immune system.
Both chemicals are known to be endocrine disruptors making safety at low doses controversial.
These results suggest that endocrine-disrupting compounds such as BPA and triclosan negatively alter immune function over the life course, in addition to posing a threat to endocrine and reproductive function.
For example, exposure to antibacterials like triclosan may lead to an excessively clean environment that disrupts the usual development of the immune system by eliminating or changing the commensal microbiota that normally helps to shape the immune system.
The researchers analyzed nationally-representative data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES), which included measurement of urinary triclosan and BPA in a random subsample of one-third of participants older than 5.
Higher triclosan levels were associated with greater odds of a diagnosis of allergies or hay fever in both age groups in the less adjusted model, although they were statistically significant only for those under age 18 in the fully adjusted model.
Unlike in adults, the under-18 group showed higher cytomegalovirus antibody titers, indicating immune cells less effective in keeping the virus in a persistent latent state, with lower levels of BPA after controlling for body mass index and socioeconomic status.
The reason for the age difference isn’t clear, Aiello’s group noted.
