Statins should be prescribed to all men over 60 and women over 75, a major study claims.
It says almost 12million adults in England ought to take the pills, which lower cholesterol, to prevent heart attacks and strokes.
However, 6.3million are not using the drugs – even though they are considered to be at high risk.
The research estimated that if all eligible adults did take statins, 290,000 heart attacks and strokes would be avoided each year.
Statins should be prescribed to all men over 60 and women over 75, a major study claims
The US study from Harvard University provides the most in-depth estimate so far of the number of adults in England who should be on statins.
According to guidance from the British health watchdog NICE, the pills should be offered to anyone with a 10 per cent risk of having a heart attack or stroke within a decade.
The researchers used this to work out how many adults should take statins based on the population’s age range, ethnicity and general health.
They claim the pills should be given to 11.8million adults.
But the fact that more than half do not receive them suggests the medication is significantly under-prescribed by GPs and shunned by patients.
The study, published in the British Journal of General Practice, found that each family doctor would have to offer statins to an extra 200 patients for the guidelines to be met.
However, many patients, GPs and academics are worried about the side-effects of the pills, which include diabetes, muscle ache and memory loss. But other experts, including NICE, say the benefits far outweigh any risks.
Previous research by experts at the University of Oxford suggested the drugs prevent at least 80,000 heart attacks and strokes a year.
There are no specific figures for the number of men aged over 60 or women over 75 who are currently taking statins.
Men tend to have heart attacks and strokes earlier in life than women, which is why they are