Children who bite their nails or suck their thumbs will be less likely to develop allergies in old age.
This news was published by Pediatrics. As part of the Dunedin Multidisciplinary Study, the New Zealand team of prof. Bob Hancox from the University of Otago followed 1037 people born between 1972-73. Between the ages of five and 32, they were subjected to periodic examinations.
Thumb sucking and nail biting were also among the behaviors recorded during the study (ages five, seven, nine, and 11). On the other hand, skin tests for allergy were carried out at the age of 13 and 32.
It turned out that in 13-year-olds who sucked their thumbs and / or bitten their nails, allergic diseases were detected by 1/3 less frequently. The same results were obtained from the study at the age of 32. It was, for example, allergic to house dust mites, dogs or cats. However, thumb-sucking or nail-biting has not been observed to reduce the incidence of asthma or hay fever.
According to the authors of the research, the obtained results may be explained by the hygienic hypothesis – according to which exposure to certain microorganisms strengthens the body’s immune system. It is known that allergic diseases are less common in people who had older siblings, an animal or lived in the countryside in their childhood.
The authors of the study do not encourage nail biting, but admit that nail biting has its advantages, as does thumb sucking.