Don't be a dipstick 3. October 2010 William Davis (32) If I want to know how much oil is in my car's engine, I check the dipstick. The dipstick provides a gauge of the amount of oil in my engine. If the dipstick registers "full" because there an oil mark at one inch, I understand that there's more than one inch of oil in my engine. The dipstick provides an indirect gauge of the amount of oil in my engine. That's what cholesterol was meant to provide: A gauge, a "dipstick," for the kind of lipoproteins (lipid-carrying proteins) in the bloodstream. Lipoproteins are a collection of particles that are larger than a single cholesterol molecule but much smaller than a red blood cell. Lipoproteins consist of many components: various proteins, phospholipids, lots of triglycerides, as well as cholesterol. In the 1960s, methods to characterize lipoproteins were not widely available, so the cholesterol in lipoproteins were used as a "dipstick" to assess low-density lipoproteins ("LDL cholesterol") and high-density lipoproteins ("HDL cholesterol"). (Actually, even "LDL cholesterol" was not measured, but was derived from "total cholesterol," the quantity of cholesterol in all lipoprotein fractions.) Some other component of lipoproteins could have been measured instead of cholesterol, such as apoprotein B, apoprotein C, or others, all meant to act as the "dipstick" for various lipoproteins. Relying on cholesterol to characterize lipoproteins provides a misleading picture. Imagine watching cars go by at high speed while standing on the side of the highway. You want to count how many people--not cars, but people--go by in a given amount of time. Because you cannot make out the detail of each and every car whizzing by, you count the number of cars and assume that each car carries two people. Whether it's rush hour, Sunday morning, late evening, rainy, sunny, or snowing, you make the same assumption: two people per car. That's what cholesterol does: It is assuming that each and every lipoprotein particle (car) carries the same amount of cholesterol (people). But that may, obviously, not be true. A bus goes by carrying 25 people. Plenty of cars may carry just the driver. People carpooling may be in cars carrying 3 or 4 people. Assuming just 2 people per car can send your estimates way off course. That is precisely what happens when your doctor tries to use conventional cholesterol values (total cholesterol, LDL cholesterol) to gauge the lipoproteins in your bloodstream. Measuring cholesterol can also provide the false impression that cholesterol is the cause of heart disease, even though it was originally meant to simply serve as a "dipstick."What we need to do is to characterize lipoproteins themselves. We can distinguish them by size, number, density, charge, and the type and form of proteins contained within. It provides greater insight into the composition of lipoproteins in the blood. It provides greater insight into the causes underlying coronary atherosclerotic plaque. It can also tell us what dietary changes trigger different particle patterns and how to correct them.Until you have a full lipoprotein analysis, you can never know for certain 1) if you will have heart disease in your future, or 2) how your heart disease was caused.Unfortunately, the vast majority of doctors are perfectly content to just count cars going by and assume two people per car, i.e., confine assessment of your heart disease risk using cholesterol . . . just as drug industry marketing has instructed them.It's not your job to educate your doctor. If he or she refuses to provide access to lipoprotein testing to better determine your heart disease risk, then consider going out on your own. Many of our Track Your Plaque program followers have obtained lipoprotein testing on their own through Direct Labs.