A type of cholesterol-lowering drug can prevent heart attacks and strokes in all at-risk patients, research suggests.
Statins are now available to buy in pharmacies
Statins are widely used to minimise the risk of cardiovascular disease in people with high cholesterol.
But researchers at the Universities of Oxford and Sydney say their work suggests the drugs could be of benefit to many more people.
The study is published online by The Lancet.
Statins are already given to around 2.5m people in the UK.
And the government ruled last year that statins should be made available over-the-counter without a prescription at chemists.
But doctors tend only to recommend them to people with high cholesterol.
The researchers analysed detailed results from more than 90,000 participants in 14 trials involving statin treatments.
They found many people presenting with lower cholesterol levels could also benefit from statin treatment.
The people who derived the greatest benefit were those whose cholesterol level was reduced the most by statin treatment - largely regardless of their starting cholesterol level.
The Medical Research Council scientist, Dr Colin Baigent, who coordinated the Oxford team based at the Clinical Trial Service Unit, said: "This study shows that statin drugs could be beneficial in a much wider range of patients than is currently considered for treatment.
"What matters most is that doctors identify all patients at risk of a heart attack or stroke, largely ignoring their presenting blood cholesterol level, and then prescribe a statin at a daily dose that reduces their cholesterol substantially."
Dr Baigent said lowering the bad 'LDL' cholesterol by 1.5 mmol/L units with a statin should reduce the risk of a heart attack or stroke by at least one third.
An LDL cholesterol level of under 3 mmol/L is considered healthy.
This study also suggests many patients given a statin would experience greater benefits if doctors aimed to achieve larger reductions in cholesterol levels.
Professor Anthony Keech, head of the Sydney team, said: "Statins are often prescribed in relatively small doses which may only reduce cholesterol modestly.
"Our results indicate that the benefits of statins appear directly proportional to the size of the reduction in cholesterol produced by treatment.
"So, bigger cholesterol reductions with more intensive treatment regimens should lead to greater benefits."
Safety fears eased
Previous research has raised concerns that statin use might be associated with an increased risk of certain cancers, or other diseases.
Researchers behind the latest study believe these concerns are probably unfounded.
Professor Rory Collins, who worked on the study, said: "This work shows clearly that statins are very safe.
"There is no good evidence that statins cause cancer, and nor do they increase the risk of other diseases.
"And although statins can cause muscle pain or weakness, our study shows that serious cases are extremely rare.
"The small excess of serious muscle problems is far outweighed by the large benefits on heart attacks and strokes."
Professor John Simes, another expert involved in the study, said: "The benefits of statin treatment were seen in all the many different patient groups studied, including women, the elderly, individuals with diabetes and those with and without prior heart attack or stroke.
"The largest benefits were seen among those at greatest risk of a vascular event."