Something Worse than LDL?

For many years doctors have believed that LDL cholesterol is the most artery-clogging lipoprotein particle circulating in the blood. Because LDL particles get into the artery wall and promote artery clogging or atherosclerosis, they have referred to it as the “bad” cholesterol. However, there are plenty of people with fairly low LDL-cholesterol levels that still develop severe atherosclerosis. Statin drugs block cholesterol synthesis in the liver and are very effective at lowering LDL-cholesterol levels. Even so, these drugs used alone usually only slow the buildup of plaque in the arteries and rarely cause regression or shrinkage of that plaque. By contrast, a very-low-fat diet has been shown to shrink atherosclerotic plaques even though the diet was actually less effective at lowering LDL-cholesterol levels than the more potent statin drugs.1

Perhaps there is another artery-clogging lipoprotein particle that has been overlooked?Dr. Proctor at the University of Alberta published the results of a study in rabbits showing chylomicron remnant particles may contribute to the growth of atherosclerotic plaques.2 Proctor labeled chylomicron particles and demonstrated that their remnants did end up in the artery wall.Proctor plans on conducting more research to determine how these particles get stuck in the artery wall and what role they may be playing in the development of artery-clogging plaques. Should these chylomicron remnants prove to be particularly atherogenic, it may help to explain why statin drugs alone and/or diets high in so-called “good fats” do little more than slow the growth of atherosclerotic plaques and rarely produce regression. This is because chylomicrons are the way nearly all the dietary fat and cholesterol gets transported in the blood. Statin drugs do not reduce their formation, so in theory the more fat and cholesterol one eats, the more potentially atherogenic chylomicron remnants will be generated in the blood and end up clogging arteries.References1 JAMA 1998;280:2001-72 Thromb Vasc Biol 2004;24:1-6By James Kenney, PhD, RD, LD, FACN.