Study authors advise patients not to stop taking their medications without talking to a doctor, because statins' proven power to prevent heart attacks and strokes outweighs any potential increase in type 2 diabetes risk. But the results — a nearly 50% increase in diabetes among longtime statin users — should throw cold water on the idea of prescribing these drugs to healthy people, which some have recommended as a way to prevent disease, says co-author JoAnn Manson, a professor of medicine at Harvard Medical School. In recent years, statins' success in preventing heart attacks — even among people without high cholesterol — has led some doctors to joke about "putting them in the water supply."
In the study, 6.4% of women who didn't use statins developed diabetes during the eight to nine years of follow-up, Manson says. That rate rose to 9.9% among statin users.