Children who had both habits had a 31% risk of allergy.
Advertisement
“It makes sense in the context of the hygiene hypothesis”, Dr. Joyce Yu, an assistant professor of pediatrics at Columbia University Medical Center, told the Daily News.
The findings support a hypothesis that states that childhood exposure to bacteria, viruses and allergens can strengthen the immune system.
Thumb sucking and nail biting are plausible candidates for exposing young children to germs in their immediate environment. Of those who sucked their thumbs or bit their nails “only forty per cent had allergies” while those with both habits, “only thirty-one per cent had allergies”. We didn’t however, find an impact on asthma, so we can’t say that it prevents children from developing asthma.
Other proposed methods to firm up our children’s immune systems include breastfeeding, natural births, outside play and other allegedly “natural” behaviors.
Although far from encouraging these habits – which can cause dental problems in children – the researchers found that they led to a natural early exposure to all kinds of allergens, such as dust, grass, animal hair (dog, cat, horse) or pollutants in general. They were asked if the statements “frequently sucks their finger/thumb” or “frequently bites their nails” applied to their child “not at all”, “somewhat” or “certainly”.
With thumb-sucking, in particular, there’s some concern that it can interfere with the alignment of the teeth as they come in.
That meant they were less likely to test positive when their skin was exposed to allergy triggers like pollen and dust mites. The most recent testing was done at age 38. Only 31 percent of the children in this group reportedly suffered from sensitivies.
When the children were 13 years old, 45% had development of allergic reactions.
Guidance on Break Thumb Sucking, a website created by an orthodontist dedicated to helping parents put an end to their child’s habit, states parents should understand the triggers for a child sucking their thumb and use a progress chart. A long-term study suggests these “bad” habits might actually have a plus side: lasting protection from common allergies. The relationship persisted to age 32.
Moreover, researchers discovered that thumb-sucking and nail-biting kids were less likely to have allergies at 13 years old than kids who only had one of the two habits.
Advertisement
The results don’t indicate an allergy cure-all. Researchers compared those who said they regularly indulged in these behaviours with those who said they didn’t suck their thumbs or bite their nails at all.
