A comprehensive review of the efficacy and safety of statins, based on 30 years' research and published in The Lancet, has concluded that the therapy's benefits have been underestimated and harms exaggerated.

Statins reduce level of bad cholesterol in the blood and are prescribed to prevent heart attacks and strokes, yet patients are often reluctant to taken them because of controversy over their safety and efficacy, which, according to Dr Richard Horton, editor-in-chief of the journal, "has harmed the health of potentially thousands of people in the UK".

The review concludes that lowering cholesterol by 2 mmol/L - with a low-cost statin therapy, such as atorvastatin, which costs about £2 per month - for 5 years in 10,000 patients would prevent major cardiovascular events in 1000 people with pre-existing vascular disease, and in 500 people who are at increased risk but have not yet had a vascular event.

On the flip side, this would cause five cases of myopathy (one of which might progress to the more severe condition of rhabdomyolysis, if the statin is not stopped), five-10 haemorrhagic strokes, 50-100 new cases of diabetes and up to 50-100 cases of symptomatic adverse events (such as muscle pain).

"Our review shows that the numbers of people who avoid heart attacks and strokes by taking statin therapy are very much larger than the numbers who have side-effects with it. In addition, whereas most of the side-effects can be reversed with no residual effects by stopping the statin, the effects of a heart attack or stroke not being prevented are irreversible and can be devastating," said review author Professor Rory Collins, Clinical Trial Service Unit (CTSU), University of Oxford.

"Consequently there is a serious cost to public health from making misleading claims about high side-effect rates that inappropriately dissuade people from taking statin therapy despite the proven benefits," he stressed.

"There should be no doubt as to the benefits of taking a statin to reduce cholesterol and we now have incontrovertible evidence from over 30 years. Statins are without doubt an effective and safe drug with a crucial role in helping prevent cardiovascular disease," noted HEART UK chief executive Jules Payne, commenting on the findings.

"The best available scientific evidence tells us that statins are effective, safe drugs that have a crucial role in helping prevent cardiovascular disease: the leading cause of morbidity and mortality worldwide," said Professor Liam Smeeth, London School of Hygiene & Tropical Medicine.

Also responding to the review, Dr Maureen Baker, Chair of the Royal College of GPs, said it cuts through a lot of the controversy surrounding statins.

"We hope this research reassures patients who are on statins that in the majority of cases statins are safe and effective drugs – but in most cases where adverse side effects are seen, these are reversible by stopping taking statins".