Study: Infectious diseases can make you dumber

Troubling new research suggests infections can impair your cognitive ability, as measured by IQ tests. The Danish study, published in the Public Library of Science journal PLOS ONE, is the largest of its kind to show a clear correlation between common infections of the stomach, skin, or urinary tract and impaired mental abilities. “Our research shows a correlation between hospitalization due to infection and impaired cognition corresponding to an IQ score of 1.76 lower than the average,” said lead researcher Michael Eriksen Benrós, M.D., with the University of Copenhagen. “People with five or more hospital contacts with infections had an IQ score of 9.44 lower than the average. The study thus shows a clear dose-response relationship between the number of infections, and the effect on cognitive ability increased with the temporal proximity of the last infection and with the severity of the infection.” Dr. Eriksen said infections in the brain affected the cognitive ability...