The story is based on a systematic review of 27 studies looking at the effect of lowering low-density lipoprotein cholesterol (LDL, the “bad” cholesterol) using statin therapy in 175,000 individuals. It found that for every 1.0 mmol/L reduction in cholesterol, taking statins reduced the risk of heart attacks, strokes and other “major vascular events”  by about a fifth (21%), even among those without existing vascular disease or at low risk of developing it.

Current guidelines recommend prescribing statins for people who have at least a 20% chance of developing cardiovascular disease within 10 years. Doctors normally calculate this risk by looking at a range of factors including the patient’s age, blood pressure, cholesterol levels, whether they smoke and whether they have diabetes.