"The right statin type for the right person at the right time may provide a relatively inexpensive means to lessen the burden of Alzheimer's,” said Professor Julie Zissimopoulos, who led the research.

Alzheimer’s disease and other dementias have now replaced heart disease as the leading cause of death in England and Wales, new figures from the Office of National Statistics revealed last month.

Last year, 61,686 (11.6%) out of a total of 529,655 deaths registered in England and Wales were attributable to dementia.

Above the age of 65, a person's risk of developing Alzheimer's disease doubles roughly every 5 years and it is estimated that dementia affects one in 14 people over 65 and one in six over 80.

Dr Doug Brown, director of research and development at Alzheimer's Society, said: "Previous research has attempted to find out whether using statins to lower cholesterol can alter a person's risk of developing dementia but these studies have produced mixed findings.

"This new study goes some way towards clearing up this confusion by analysing large amounts of existing data of people who use different types of statins over a long period of time.

"Their refreshing approach highlights that 'one size fits all' is not always a suitable approach to healthcare and this is likely to be the case when it comes to ways people can reduce their risk of dementia."