There have been several studies looking at how general anesthetics affect brain cells.

Some studies have found that certain types of general anesthetics seem to lead to increased levels of the Alzheimer’s hallmark toxic clumps of amyloid and tau proteins in brain cells, according to the Alzheimer’s Society of the U.K. These proteins are thought to cause damage to brain cells in Alzheimer’s disease.

Because cognitive changes are commonly observed in older adults after surgical procedures, scientists in Canada examined the associations between the development of dementia and exposure to general anestesia compared with regional anesthesia administered for elective surgical procedures.

For its study, the researchers linked administrative databases from ICES (formerly called the Institute for Clinical Evaluative Services) in Ontario. They included “all community‐dwelling individuals aged 66 and older who underwent one of five elective surgical procedures in Ontario, Canada, between April 1, 2007, and March 31, 2011. Individuals with evidence of dementia preceding cohort entry were excluded. Individuals who received GA were matched within surgical procedures to those who received RA on age, sex, cohort entry year, and a propensity score to control for potential confounders.”

In all, 7,499 matched pairs were included in the final analysis. The researchers found no difference in the risk of being diagnosed with dementia for individuals who received general anesthesia when compared with regional anesthesia. “There was also no association between anesthesia and dementia in most subgroup and sensitivity analyses,” they wrote.

The team concluded elective surgery using general anesthesia was not associated with an overall elevated risk of dementia when compared with regional anesthesia.