Study reveals positive side to your child's thumb-sucking

Dentists and orthodontists get ready for this: a new study published in the Journal of Pediatrics (1) shows that children who bite their nails and suck their thumbs are about one third less likely to develop certain allergies.

"Cat, grass, house dust mite, and dog; those were reduced, some significantly, some borderline," said Professor Malcolm Sears of McMaster University School of Medicine. "Early exposure to dirt is not a bad thing," reports Sears. "When they suck their thumbs or bite their nails, they're exposing themselves to additional microbes or dirt which is stimulating the immune system."

According to a recent article in Time magazine, the findings support the hygiene hypothesis, which says that early exposure to things like bacteria, viruses and allergens can prime the immune system to be stronger and better able to respond to any microbial attacks.

It's possible that the germs that children ingest from sucking their thumbs or biting their nails sets up certain populations of microbes in the gut that can educate the immune system and get it ready to mount attacks against other, more unfriendly and disease-causing germs.

Say it isn't so! All those years of my own thumb-sucking woes and eventually worry over my daughter's ever shrinking palate was really a waste of energy. I should have been focusing more on the positives and less on the barely visible set of buck teeth that we both now have.

And yes, there are positives. The results from the study tell us not to "be quite so afraid of a little bit of dirt," says Dr Malcolm Sears, a respirologist at McMaster University and one of the co-authors of the study. "We're not sure what it is in dirt, whether it's microbes or some other substance, that actually protects us.

So, parents of thumb- and finger-suckers should tuck this study away for future reference. Take note over the next several years and see if your kids do end up with fewer ailments.

I should note that before you go shoving that tiny thumb in your baby's mouth or telling your six- year-old to suck away, remember that researchers have still said loud and clear that this isn't a recommendation for kids to take up this habit and medical/dental professionals still advocate weaning kids off of their thumb and fingers as soon as you can.


1. Thumb-Sucking, Nail-Biting, and Atopic Sensitization, Asthma, and Hay Fever | Articles | Pediatrics


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