No evidence for statins preventing dementia

Clinical question: 
Do statins prevent dementia?
Bottom line: 
There is good evidence statins given in late life to individuals at risk of vascular disease have no effect in preventing Alzheimer's disease (AD) and dementia. The age range of participants was 40-82 years across the 2 studies.
Cognition was measured at different times and with different scales in the 2 studies so could not be combined in a metaanalysis. The mean follow-up period was 3.2 years in 1 study and 5 years in the other.
PAD is the most common form of dementia affecting up to 15 million individuals worldwide. AD has a prevalence of approximately 1% among 60 to 64-year-olds, rising to 40% in those age 85 years and older. Biologically it seems feasible statins could prevent dementia due to their role in cholesterol reduction and initial evidence from observational studies was very promising.
Review CD#: 
July, 2009
Authored by: 
Brian R McAvoy