Evidence is lacking to support widespread use of cholesterol-lowering drugs among the "worried well", a study has found.
Statins are highly effective at reducing blood cholesterol levels and are routinely given to heart patients.
But some GPs also advocate their wider use for at-risk patients, and a number of healthy doctors take the pills themselves on a precautionary basis. Low dose statins are also available over-the-counter at pharmacies without prescription.
The new findings from a review of 14 statin trials found that the drugs did reduce death rates and helped prevent heart attacks and strokes.
However the authors, who sifted through data on more than 34,000 patients, concluded there was insufficient evidence to justify widespread use of statins in people with no previous history of heart disease.
They stressed the need for caution when balancing the risks and benefits of statins - and questioned the validity of drug company-sponsored trials.
Lead researcher Dr Fiona Taylor, from the Cochrane Heart Group at the London School of Hygiene and Tropical Medicine, said: "It is not as simple as just extrapolating the effects from studies in people who have a history of heart disease.
"This review highlights important shortcomings in our knowledge about the effects of statins in people who have no previous history of CVD (cardiovascular disease). The decision to prescribe statins in this group should not be taken lightly."
The findings are published in the Cochrane Library, which produces comprehensive reviews of drug trial evidence.
The researchers pointed out that all but one of the studies they looked at were industry-sponsored. Dr Taylor added: "We know that industry-sponsored trials are more likely to report favourable results for drugs versus placebos (inactive dummy drugs), so we have to be cautious about interpreting these results."
