ABSTRACT: When researchers first produced atherosclerosis in rabbits by feeding them cholesterol, they argued that atherosclerosis was of an "infiltrative" rather than "degenerative" character. That is, cholesterol was so abundant that it infiltrated the blood vessel wall. Over the decades it has become clear, however, that atherosclerosis is an attempt to protect the lining of the blood vessel from toxic waste generated by the degeneration of vulnerable lipids. The process of molecular degeneration can be likened to breaking glass, and the formation of atherosclerosis can be likened to the process of cleaning up the broken shards. The danger is not gone forever, though, because these toxic waste management sites (or barrels of broken glass) can eventually burst and spill their contents into the blood, leading to clotting, oxygen starvation, and the death of local tissue that can result in a heart attack or stroke. The key to preventing heart disease according to the new paradigm is preventing the molecular degeneration in the first place. Understanding this will help us achieve the protection from heart disease that our ancestors had.