There is not enough evidence to suggest that taking statins can lead to cognitive decline or increase the risk of Alzheimer's disease, researchers in the US claim.
Published in the Annals of Internal Medicine journal, the study reviewed current evidence and concluded that reports of statins risks are contradictory.
The team, made up of researchers from the University of Pennsylvania and Stanford University Medical Centre, searched a wide range of literature, including those on clinical trials and cohort studies.
Each of the studies was assessed for quality based on findings and the number of people who took part. Some 57 studies made up a systematic review and 25 of those were included in a meta-analysis.
Afterwards, the team was agreed that no evidence of increased risk could be identified. However, they did found some signs suggesting that statin users have a reduced risk of Alzheimer's disease, but were not prepared to make "unequivocal conclusions" until further research is carried out.
Dr Simon Ridley, head of research at the charity Alzheimer's Research UK, said it is natural that people become worried when they hear that drugs they be prescribed can lead to cognitive issues
He hopes this review will go some way to alleviating their concerns.
"By pulling together the best available evidence, reviews like this one can provide a much clearer picture of the benefits and side-effects of specific treatments," he said.
"Research like this is vital for helping doctors make fully informed decisions about what treatments to prescribe. Anyone with questions or concerns about any medication they are taking should talk to their doctor."
He added that although the review found a possible link between statins and a lower rate of Alzheimer's, readers should not view the drugs as a prevention tool for the condition.
An estimated 820,000 people are currently living with some form of dementia in the UK and that figure is likely to rise above the one million mark by 2021.