Kids eat all sorts of things, from dirt to glue to boogers. But next time your kid starts digging for gold – and subsequently consumes it – don’t freak out. He might be on to something.
Scott Napper, a professor of biochemistry from the University of Saskatchewan in Canada, thinks that swallowing that snot might actually benefit your health.
According to ABC News, “Napper contends that eating boogers exposes people – and their immune systems – to the pathogens inside.” Early exposure to pathogens could actually help boost a child’s immunity against allergies and asthma.
Others disagree. They might be justified if your child ate someone else’s boogers, says Dr. Charles Barone, pediatrician with Henry Ford Medical Group.
But “if you have bacteria and viruses or other things inhabiting your nose,” he says, “you tend to have immunities to those.”
While the booger hypothesis has yet to be tested, a recent study links bacteria to boosted immunity in babies – further supporting what’s called the “hygiene hypothesis.”
The hygiene hypothesis defined
The Asthma and Allergy Foundation of America reports that 30 percent of American adults and 40 percent of American children have allergies. The Centers for Disease Control and Prevention reports some 6.3 million children have asthma. Sterile environments, according to the hygiene hypothesis, have something to do with this.
“The hygiene hypothesis has affected how obsessed we are about a perfectly clean environment,” Barone says.
The hypothesis, according to the UCLA Food and Drug Allergy Care Center, states that excessive cleanliness interrupts the normal development of the immune system.
When that development is hindered, children become more susceptible to developing allergies or asthma. Therefore, good sanitation practices and “eradicating” infections may actually be increasing the number of people with allergies.
“The immune system is very robust in children,” Barone says. “It’s ready to roll.”
So parents don’t have to worry about some exposure to germs and infections early in a child’s life, because the body can fight it off.
A newer development
Which leads us to a Swedish study that came out in recent years about parents’ spit – and their babies’ health. It found infants were less likely to develop asthma or itchy rashes if their parents sucked on their pacifiers to clean them, instead of running the pacifier under tap water.
The study, which included 184 babies, found that “the transfer of mouth microbes from parents to baby may help boost the bacterial diversity of the young child’s digestive system and foster immunity.”
Of the tykes, 80 percent had at least one parent with allergies, which made the child more prone to developing allergies.
This study, says Barone, further supports the hygiene hypothesis, because children are getting exposure to some of mom’s bacteria from her mouth.
It’s also one of the first “more practical” experiments when it comes to the benefits of germs, Barone says. “I think that’s what we’re struggling with right now. How does this translate to what we tell mom?”
“In fact, we know that based on the hygiene hypothesis, it’s probably better for there to be some germs,” he says.
Keep it clean
“Things are a little bit in flux because of that thinking,” Barone says of the hygiene hypothesis. “We probably don’t need to be as compulsive about this completely sanitary environment that children grow up in.”
So step away from the hand sanitizer. Kids don’t need every single germ scrubbed off their bodies – and they don’t need to live in a sterile environment.
But that doesn’t mean your kid should chow down on boogers all day – or entirely avoid cleaning up.
Kids should wash their hands before they eat. And, Barone says, “We always recommend a good hand washing, especially when they are in school.”
This post was originally published in 2013 and has been updated for 2016.