At his blog, Jonathan Eisen has awarded his 'Overselling the Microbiome' award to the New York Times for its coverage of a study that found that kids who sucked their thumbs or bit their nails were less likely to develop allergies.
The piece was based on a study in this month's issue of Pediatrics that examined the relationship between thumb sucking or nail biting and atopic sensitization, asthma, or hay fever. The University of Otago-led team reports that kids who sucked their thumbs or bit their nails were less likely to have positive skin-prick tests for atopic sensitization by age 13, a protection that appear to persist into their 30s. The team did not find any association between thumb sucking or nail biting and asthma or hay fever. The researchers said that their findings lend credence to the 'hygiene hypothesis' that says that early-life exposure to microbes reduces allergy risk.
At the Tree of Life, Eisen says the study is interesting, but notes that the researchers uncovered a correlation. The Times, he adds, instead made the jump to causality. The Times' Perri Klass wrote that the "study suggests that those habits in children ages 5 to 11 may indeed increase exposure to microbes, but that that may not be all bad." Eisen writes, though, that the study "is consistent with that, but it is consistent with many other explanations." And for that, he bestows his 'Overselling the Microbiome' award.