Thumb Sucking And Nail Biting In Children Lowers Risk Of Allergies

By on July 11, 2016

According to a new study conducted by University of Otago, New Zeland that children who are thumb suckers and nail biters are at lower risk of developing allergies in life.

The findings were taken from long running Dunedin Multidisciplinary Study. This study is conducted by following the progress of 1,037 participants who were born during 1972-73 in Denedin, New Zealand till their adulthood.

The findings of this study appeared in August issue of “Pediatrics”, which is an US journal. It suggests that risk of developing allergies is less in children who are exposed to microbial organisms through thumb sucking and nail biting.

The lead author of this study, Professor Bob Hancox says that exposure of microbials may result in alteration of immune system of the thumb sucking and nail biting children, and they become less prone to developing allergy.

Parents of the members who participated in Dunedin Study reported that their children were habituated to thumb sucking and nail biting from the ages of 5, 7, 9, and 11 years old.

Thumb Sucking And Nail Biting Lowers Allergies

These members were again checked in the age of 13 and 32 for atopic sensitization. They were defined as positive skin prick test to at least one common allergen.

When these members were checked at 13 years of age, the prevalence of sensitization was less (38%) in children who had the habit of thumb sucking or nail biting when compared to children who did not had the habit (49%).

Professor Hancox said that this risk was even lower in children who had both thumb sucking and nail biting habits (31%).

This lower risk of allergens sustained even in adulthood i.e. 32 years of age, and there was no difference observed in association of confounding factors like parental smoking, allergen parents, sex, ownership of pets, exposure to house dust mites, and breast feeding.

Professor Hancox said that the finding support the “hygiene hypothesis”. According to hygiene hypothesis, the risk of developing allergens lowers with exposure of microbes in childhood.

Malcolm Sears is the co-author of this study. Malcolm Sears is from McMaster University’s Michael G. DeGroote School of Medicine, and formerly from Dunedin.

Malcolm Sears suggests that even though their research supports hygiene hypothesis, they do not recommend for encouragement of these habits as it is still unclear if there are true positive side of these habits.

Ms Stephanie Lynch, a medical student, who undertook the study as a summer project, said that even though this research lower risk of allergies observed in thumb sucking and nail biting children, there was no difference found in developing risk of asthma and hay fever in children with and without these habits.

Photo Credits:

Original Article: Bob Hancox

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