The research, published in a leading journal examined 25,970 patients over ten years and discovered statin users had a higher incidence of diabetes and also weight gain.
Patients using the drugs also had more than double the risk of diabetic complications including eye, nerve and kidney damage.
Scientists say the new research published in the leading Journal of General Internal Medicine, confirms a long suspected link between statin use and diabetes.
Professor Ishak added: “There is not enough funding to carry out studies to assess these long term effects that are not funded by drug companies and therefore clouded by conflicts of interest.”
And he said drugs may be doing more harm than good for people at low risk of heart disease: “I am sceptical about the prescribing guidelines for people at lower risk (of heart disease). I am concerned about the long term effects on the huge population of healthy people on these drugs who continue for many years.”
And Dr Malcolm Kendrick, who has studied statins and heart health said: “There have been a number of small studies that have suggested an increase in the risk of diabetes and statin use. However this large and long term study has confirmed this is a significant problem. “
He added: “This study demolishes the argument that these drugs should be prescribed to anyone, as the harms may outweigh previously suggested benefits.”