May 6th, 2013
01:15 PM ET
As a parent, there are undoubtedly a few things you do now that before you had children you thought were gross: Changing diapers, wiping up vomit and using your own spit to clean off a child's pacifier, just to name a few.
Though it's hard to admit, most parents have done the latter. You're out at the mall when your kid drops his pacifier and there's not a place to clean it nearby. So you pick it up, suck on it a bit and hand it back to your baby.
What's the harm?
Turns out cleaning a recently dropped pacifier with your saliva - meaning you put it in your mouth before inserting it back into your baby's - may actually help strengthen your child's immune system and keep him from developing certain allergies, according to a new study in the journal Pediatrics. When parents cleaned pacifiers in this way their children were significantly less likely to develop eczema, a skin condition considered to be the most common early form of allergies.
Researchers enrolled about 180 Swedish children in the study and took samples of their saliva. Babies whose parents had put the pacifier in their own mouths to clean it had a different microbe soup, if you will, then those whose parents had either rinsed the pacifiers under water or boiled it.
At 18 months the children whose parents licked the pacifiers had one-third the risk of developing eczema compared to children whose parents used a different cleaning method.
The scientists also looked at the number of respiratory infections among the children. They found that both groups, on average, had the same number of infections, no matter how the pacifiers were cleaned.
Behind the results
It seems counter-intuitive - wouldn't adding your germs to the floor dirt on the pacifier make your baby sick?
Scientists think that sucking the pacifier transfers some of Mom or Dad's bacteria to the infant. Research has shown that babies need to be exposed to a wide variety of bacteria, viruses and other organisms to help their immune systems develop and mature properly. If this doesn't happen early, the baby's system tends to overreact to harmless particles like cat hair, pollen, or various foods, treating them as if they are dangerous, which can lead to allergies.
Our emphasis to keep things exceedingly clean over the last few decades may actually be depriving a baby's immune system of some of the organisms it needs to help it thrive, according to the study.
"Should we change our behavior based on this study?" asks Dr. Elizabeth Matsui, a pediatric allergist and immunologist at Johns Hopkins Children's Center and member of the American Academy of Pediatrics Section on Allergy and Immunology Executive Committee. "I would say no."
"But this study does bring up intriguing questions about the oral bacteria and how it might influence a developing immune system in a positive say to protect against allergy," adds Matsui. She says more studies are needed to see if these findings can be replicated.
Bottom line: The next time you're out at the mall and have forgotten an extra pacifier, don't be too concerned if you need to clean the dropped one with your own saliva.
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.