Atherosclerosis is a condition in which the wall of arterial blood vessels thickens as the result of a build up of fatty materials ─ so-called plaques. If a plaque suddenly ruptures it can cause the formation of a clot (thrombus) that rapidly slows or stops blood flow, leading to death of the tissues fed by the artery. A thrombosis of a coronary artery can cause a myocardial infarction (heart attack) and a thrombosis of a brain artery can cause a stroke. Atherosclerosis of the blood vessels to the legs (peripheral artery disease) can lead to pain when walking.

The underlying cause of atherosclerosis is a chronic inflammatory response in the arteries leading to a hardening of the vessel walls. This process is promoted by the oxidation of low density lipoprotein (LDL) cholesterol through free radicalsAntioxidant nutrients can potentially protect the arterial wall against the damaging oxidative effects.