‘Being Too Clean May Not Be Good’ for Baby


For years I’ve been committed to (some would say obsessed with) the idea that the cleaner I keep my home, the healthier my kids will be. Many of us parents have spent hours scrubbing floors, sanitizing toys and wiping down countertops. We’ve shielded our newborn babies from pets and strangers and insisted our kids wash their hands a dozen times per day.

Now a new study suggests that moms like me have been doing it wrong. In fact, early exposure to allergens and bacteria may be linked to lower incidences of allergies and asthma later in life.

The study, published in the Journal of Allergy and Clinical Immunology, looked at 467 children from birth through 3 years old. Participants were screened for allergies every year, and their homes were tested for allergens and bacteria.

Researchers were surprised by the results. Children exposed to mouse and cat dander, as well as cockroach droppings, before they turned 1 year old actually experienced lower rates of allergies and wheezing by age 3 than kids who were not exposed. In fact, kids who were not exposed were three times more likely to have allergies and experience wheezing. Exposure to bacteria was also linked to lower rates of allergies. However, exposure after the first birthday did not have the same result.

“We’re not promoting bringing rodents and cockroaches into the home, but this data does suggest that being too clean may not be good,” study co-author Robert Wood, chief of the division of allergy and immunology at the Johns Hopkins Children’s Center, told NBC News.

The study has some very interesting implications for how we think about our families’ environments, especially since, as Wood notes, “a lot of immune system development that may lead someone down the path to allergies and asthma may be set down early in life.”

“This study confirms what a lot of us believe, which is that one of the reasons asthma, allergies and food allergies are on the rise is because of our sterile environment,” says Amy Shah, who specializes in asthma, allergies and immunology at Valley E.N.T. in Arizona.

“The ‘hygiene hypothesis’ basically says that too-clean environments promote allergies, including food allergies and asthma, because there is not enough exposure to various bacteria and allergens in early life,” Shah says. “Westernized countries have double the risk of asthma, allergies and eczema. Asthma affects as much as 40 percent of the population in regions of New Zealand, Australia and the United States. By contrast, most third world countries continue to have much lower rates of all allergic diseases.”

Shah notes that a previous study found that kids who grow up on farms also have a lower risk of allergies and asthma.

Although researchers are still working to translate their findings into practical tips for parents, Shah offers these suggestions, which challenge traditional thinking in terms of raising kids.

  • Let your kids get dirty!
  • Don’t over-sanitize children’s hands.
  • Avoid antimicrobial soaps and sprays. Most cuts and scrapes can be cleaned with an alcohol wipe, and kids’ bodies need just plain soap and water.
  • Be very judicious with the use of antibiotics. Most ear infections, sore throats and colds don’t require antibiotics, so work with your pediatrician to wait it out at least 7-10 days.
  • Don’t be afraid to share food and water with your child. In fact, for babies, parents’ saliva is actually beneficial.

Perhaps this study will lessen many parents’ fears about their kids getting dirty or being exposed to bacteria. At the very least, it may mean less guilt if you don’t have time to clean the bathroom right away!