Further studies should be done to directly test statins to prevent Alzheimer's-related brain changes, notes University of Washington's Gail Li, MD, PhD.
Participants had enrolled in the study when they were at least 65 years old (average age: 74). At the time, they had healthy minds.
Participants took mental skills tests every other year for up to eight years. If they scored poorly on those tests, they were screened for dementia.
On average, participants died when they were in their late 70s to early 80s.
The researchers checked participants' medical records for statin prescriptions, except for the statins Lescol and Crestor, which weren't included in the data.
The brain autopsies showed that participants who had taken statins were 80% less likely to have brain changes typical of Alzheimer's disease than those who hadn't taken statins.
That figure is adjusted for risk factors including age, gender, and mental skills test scores when the study began.
However, the researchers couldn't control for all influences, including the possibility that participants in the frailest health were less likely to get statin prescriptions.
"Our findings should be extrapolated to living populations with the greatest caution, if at all," Li's team warns.
In short, don't bank on statins for Alzheimer's prevention until more research is done.