(Credit: gerain/Shutterstock) A new study on the possible health benefits of thumb sucking bolsters the decades-old, controversial "hygiene hypothesis," which claims that exposure to some bacteria early in life could improve health down the road. The latest results come from the Dunedin Multidisciplinary Study, which has followed more than 1,000 people in New Zealand over four decades. Researchers from the University of Otago used the data to see if thumb-sucking and nail biting, both common childhood behaviors, were correlated with lower rates of allergic reactions later in life.
After sifting through the data, the researchers found limited evidence to support the hygiene hypothesis. For the study, parents were asked to report thumb-sucking and nail-biting behaviors when children were between 5 and 11 years old, and the participants were tested for allergies via a skin test when they were 13 and 32. Researchers looked at a range of common allergies including ...
