Although a link between the drugs and diabetes has been seen in earlier studies, researchers had always assumed that the patient already had signs of heart disease, and it was this, rather than the statins, that was the cause.

But the new study, involving 25,970 people, plotted the progress of 3,351 of them who were healthy and had no signs of heart disease before they started statin medication, and most commonly simvastatin, marketed as Zocor.

During the eight years of the study, the group taking statins had a 1.87-fold increased risk of developing diabetes for the first time, compared to non-statin users, and a 2.5-fold increased risk of diabetes with complications.

Lead researcher Ishak Mansi from the VA North Texas Health System in Dallas said he was surprised by the high risk of diabetes seen in healthy people taking a statin. The association can’t be argued away by the “sicker patient” default used by other researchers, he said, and the use of statins was the only significant difference between the two groups he monitored.

If you’re worried about developing heart problems, it’s better to change your lifestyle than take statins, especially if you’re healthy, says Dr Mansi.