General anesthesia for the elderly boosts the risks of dementia by more than a third, according to a study by French doctors.
Researchers led by Francois Sztark at the University of Bordeaux in southwestern France analyzed data from a long-term study into cognitive decline covering 9,300 elderly people in three French cities.
The volunteers — average age 75 — were interviewed when they were recruited into the study and then two, four, seven and 10 years afterwards.
The data, which was released on May 31, showed a link between the onset of dementia and a general anesthetic that had been administered two or three years before.
Those who had received general anesthesia were 35 percent likelier to develop dementia symptoms by the next follow-up interview compared with counterparts who had not had general anesthetic.
Previous work has already highlighted a condition called post-operative cognitive dysfunction, or POCD, in which an elderly patient who undergoes major surgery also goes into mental decline relatively soon afterward.
The reasons for this, though, are unclear. Some experiments suggest various anesthetics inflame neural tissues, causing protein plaques and tangles to develop that are precursors of Alzheimer’s disease.