Thumb Suckers and Nail Biters Have Fewer Allergies

Thumb Suckers/Nail Biters – Hygiene Hypothesis – Strengthens Immune System

According to a study, children who tend to suck their thumb or bite their nails seem to be less likely to develop allergies. The explanation, according to the authors in the journal Pediatrics, is the hygiene hypothesis - exposure to some germs which strengthens the immune system of the body. In New Zealand, thumb sucking and nail biting looked to prevent some allergies among 1,000 individuals that were assessed and recorded periodically at the age of five, seven, nine and eleven and allergies were tested for at age thirteen and thirty-two.

However the habits did not have any bearing on asthma or hay fever threat. Around a third of the children were regular thumb suckers or nail biters. They were considerably less likely of have allergies at the age of 13. The possibilities of these children developing allergy to things like house dust bug or pet cat or dog was around a third less than those of the others who did not have these habits.

 Senior author Dr Robert Hancox of the Dunedin School of Medicine at the University of Otago, Dunedin, New Zealand, stated that in this research, it was impossible to ascertain that thumb sucking or nail biting could cause decrease in allergies.

Pets at Home/Living on Farms – Identified as Environmental Influences

He had informed Reuters that it is always possible that there could be another explanation for this association though it is difficult to suggest what it could be.Prof Malcolm Sears, who is a researcher for the Firestone Institute for Respiratory Health at McMaster and St. Joseph’s Healthcare Hamilton, stated that the findings are consistent with the hygiene theory that early contact to dirt or germs reduces the risk of developing allergies and while they did not recommend that these habits could be encouraged, there does seem to be a positive side to these habits.

 Holly Shaw of Allergy UK commented that `research that has been carried out in other countries also adds weight to this theory of the part of the environment and gut macrobiotic tend to play in shaping the potential of the individual to develop a food allergy. Having pets at home, older siblings and staying on a farm have also been identified as environmental effects which may have a role in the development of allergic disease.

Increased Microbial Exposures – Affecting Immune System

The researchers tested the idea that common childhood habits of thumb-sucking and nail-biting could have increased microbial exposures, affecting the immune system as well as dropping the development of allergic reaction which is known as atopic sensitization.

From all the children at 13 years, around 45% indicated atopic sensitization though among those with one oral habit only 40% seemed to have allergies. From those with both habits, only 31% had the allergies. This tendency continued right into adulthood showing no difference based on smoking in the home, possession of cats or dogs or exposure to house dust bugs.

The idea that thumb sucking and nail biting would likely decrease the risk of allergies later would need to be supported by various studies in different geographical states across the globe, according to Emmanuel Prokopakis of the University of Crete School of Medicine in Greece who has not been part of the new study.