Atherosclerotic cardiovascular disease risk is determined by cumulative lifetime exposure to low-density lipoprotein (LDL) cholesterol, with subclinical atherosclerotic plaque formation initiating at LDL cholesterol levels as low as 60 mg/dL.

Study: Beyond Early LDL Cholesterol Lowering to Prevent Coronary Atherosclerosis in Familial Hypercholesterolemia.

The study shows that the longer and more LDL cholesterol builds up in the blood, the more plaque forms in arteries, which supports the idea that heart disease risk depends on lifetime cholesterol exposure.

Study: Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel

The study shows that the longer and more your LDL cholesterol is high, the higher your heart disease risk, which supports the idea that damage starts early—even at low levels.

Study: The LDL cumulative exposure hypothesis: evidence and practical applications

The study says that the longer and more your LDL cholesterol stays high, the more likely you are to develop heart disease over time — which matches the idea that damage can start even when cholesterol isn’t extremely high.

Study: Carbohydrate Restriction-Induced Elevations in LDL-Cholesterol and Atherosclerosis

The study looked at healthy people on keto diets who had very high LDL cholesterol, but they didn’t have more heart plaque than people with normal LDL. This suggests that very high LDL doesn’t always mean more plaque, at least in the short term.