A lack of ulcers may be driving the increased incidence of childhood asthma, Reuters reports. In a study of children infected with the H. pylori bacteria, which causes ulcers, those who had the infection were 59% less likely to have asthma than those who didn't. H. pylori infection has been waning for decades, and the connection may explain spiking childhood asthma rates over the same period.
"The disappearance of Helicobacter...is consistent with the decline of both ulcer disease and stomach cancer," said an NYU researcher, but "it is also consistent with the rise of asthma." The scientists wrote, "One explanation has been termed the 'hygiene hypothesis’: that humans are more prone to allergic disorders because of a lifestyle that may be too 'clean.'"