Habits such as nail biting and sucking thumbs, which parents deem bad, may actually have positive outcomes. This is what Researchers of New Zealand’s Dunedin School of Medicine are saying.
The research which was published in the journal Pediatrics, was also assisted by professor Malcolm Sears of McMaster University’s Michael G. DeGroote School of Medicine.
Sears said
“Our findings are consistent with the hygiene theory that early exposure to dirt or germs reduces the risk of developing allergies,” he also added that “While we don’t recommend that these habits should be encouraged, there does appear to be a positive side to these habits.”
The purpose of the research was to test whether thumb-sucking and nail-biting would increase microbial exposures, which in essence affects the immune system and reduce the development of allergic reactions which is also known as atopic sensitization.
The children involved in the project had their nail-biting and thumb-sucking habits recorded when they were 5, 7, 9, and 11 years old. They were then given a skin prick test at the ages of 13 and 32 for atopic sensitization, which is designed to see whether they were allergic to at least 1 common allergen, such as grass, dust mites or household pets.
They found that 31% of the children were frequent thumb suckers or nail biters.
At 13 years old, 45% of the children showed atopic sensitization, but among those with one oral habit, only 40% of them had allergies.
Those kids with both habits – only 31% had allergies.
This trend was sustained into adulthood – as the benefits continued through to when participants were 32 years old.
While the results showed thumb-suckers and nail-biters had lesser rates of allergy in the test, there were no associations with asthma or hay fever.
Researchers do not know exactly how to explain this correlation.
“Even if we assume that the protective effect is due to exposure to microbial organisms, we don’t know which organisms are beneficial or how they actually influence immune function in this way,“ Respiratory Epidemiologist Robert J. Hancox from the University of Otago in New Zealand recently told the New York Times.
Although it will take a while for researchers to find out the exact reasons, the findings are certainly interesting!