New research shows a clear correlation between infections and impaired cognitive ability measured by IQ.
“Our research shows a correlation between hospitalisation due to infection and impaired cognition corresponding to an IQ score of 1.76 lower than the average,” says Michael Eriksen Benrós, of 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 showed infections in the brain affected the cognitive ability the most, but many other types of infections severe enough to require hospitalisation also impaired a patient’s cognitive ability.
“Moreover, it seems that the immune system itself can affect the brain to such an extent that the person’s cognitive ability measured by an IQ test will also be impaired many years after the infection has been cured,” said Eriksen Benrós.
The research was a collaboration between researchers from the University of Copenhagen and Aarhus University. It was the largest study of its kind to date, involving 190,000 Danish participants.