Is your little one a thumb sucker? Or how about a nail biter? A recent study shows that children who are either are less likely to develop allergic sensitivities. And, if they have both habits, they’re even less likely to be allergic to things like house dust mites, cats, dogs and grass.
“Our findings are consistent with the hygiene theory that early exposure to dirt or germs reduces the risk of developing allergies,” said Malcolm Sears, professor at the Michael G. DeGroote School of Medicine at McMaster University in Canada who assisted with the research. “While we don't recommend that these habits should be encouraged, there does appear to be a positive side to these habits.
The study was done by researchers from the Dunedine School of Medicine in New Zealand and published in the journal Pediatrics. The goal was to test if “the idea that the common childhood habits of thumb-sucking and nail-biting would increase microbial exposures, affecting the immune system and reducing the development of allergic reactions also known as atopic sensitization,” says the press release for the study.
Research involved analyzing data taken from more than 1,000 New Zealand children. Their habits of thumb-sucking and nail-biting were measured at ages 5, 7, 9 and 11. Then, they were tested for allergic reactions through skin-prick testing at 13 and 32 years old.
Results showed that out of all the children at 13 years old, 45 percent showed allergic reactions. However, of those who either sucked their thumbs or bit their nails, only 40 percent had allergies. And among those with both habits, only 31 percent had allergies.
A similar study published late last year in the journal JAMA Pediatrics, on the other hand, aimed to find out if exposure to dogs and farm animals affected the likelihood of childhood asthma. They found that babies who lived with dogs during their first year of life were 13 percent less likely to get asthma by the time they hit school age.
“We know that children with established allergy to cats or dogs should avoid them, but our results also indicate that children who grow up with dogs have reduced risks of asthma later in life,” says senior author of the study Catarina Almqvist Malmros, pediatrician and professor at the Karolinska Institute in Stockholm.
When it comes to peanut allergies, another study (published in the New England Journal of Medicine) found that early exposure to peanut products could cut a baby’s risk of developing a peanut allergy by 80 percent.
Lead author of the study Gideon Lack ,Professor of Paediatric Allergy at the King’s College London, said it all had to do with exposure to new food rather than being afraid of food allergies. “The food is excluded from the diet and, as a result, the child fails to develop tolerance.”
There might be something to exposing kids to as many things as possible to build up their immune systems. But, more research is needed before anything conclusive is reached. In the meantime, as the researchers have said, it’s best not to encourage bad habits in the attempt of trying to get your child less likely to be allergic to something.