Last week I spent an hour watching Dr. Robert Lustig, Professor of Biochemistry at the University of California at San Francisco, deliver a lecture on the role that sugar, particularly fructose, is playing in our obesity epidemic.  The lecture included a section on cholesterol.  The first thing I’m going to say about cholesterol is that we don’t understand it well enough.  And what we think we know, we don’t know, because what we don’t understand fills a much bigger vessel than what we do understand.

On my first day of medical school in the early 1990’s, the Dean of Students came in to address us.  He said that half of what we would learn over the next few years would turn out to be false.  The problem was that no one knew which half!  Here are some of the things I was taught in medical school that have turned out to be false:

            LDL cholesterol is the bad cholesterol.

            Eggs and butter increase your bad cholesterol.

            There is no reliable way to increase your good cholesterol (HDL).

            We don’t really know how triglycerides fit in, but they don’t seem to really matter anyway.

Let’s discuss these false statements one at a time.

LDL comes in two major types, 1) small and dense or 2) big and fluffy.  Small, dense LDL is the bad one.  Large, fluffy LDL is ok.  Small, dense LDL is highly atherogenic (causing plaque formation, atherosclerosis, heart disease).  It’s like sand.  It gets stuck everywhere and starts plaque formation.  It reminds me of the grain of sand that irritates an oyster, which responds by coating that sand particle with layers of nacre, the shiny, luminescent stuff that results in pearls.  Humans don’t get pearls.  We get heart attacks and strokes.

Then there are the big, fluffy LDL particles that float through the blood stream without attaching to the walls of the blood vessels.  While it’s true that eggs and butter raise your cholesterol, it’s not true that they increase your bad cholesterol.  Eggs and butter increase the big, fluffy LDL.  That’s good.  If you want to know what kind of LDL you have, you can ask your doctor to run a VAP panel instead of a standard lipid profile.  The VAP panel will show how much of your LDL is small and dense, and how much is large and fluffy.

HDL cholesterol is called the good cholesterol.  H for healthy.  The lower your HDL, the greater your risk of developing hardening of the arteries.  There are a number of important research studies that show low HDL to be a much more serious risk factor than high LDL (just the small, dense kind as you now know).  There are a number of reliable ways to increase your HDL.  All of them have one thing in common.  They improve your insulin sensitivity, so it works more efficiently and you end up needing and using less insulin.  I see very low HDL levels in several kinds of patients. They are usually people whose diets consist of large amounts of 1) fast food, 2) processed food, and/or 3) refined [stripped] grains, with very little produce.

How can you raise your HDL?  By decreasing the amount of fast and processed food you eat.  By getting more exercise (to improve your insulin sensitivity).  By eating foods that are rich in B vitamins.  B vitamins are found in abundance in whole grains, fruits and vegetables, and nutritional yeast.

What are triglycerides?  If HDL is the good cholesterol, and small, dense LDL is the bad cholesterol, then triglycerides are the ugly cholesterol.  The goal from a medical standpoint is to get the triglycerides below 150, but the truth is that the lower they are, the better.  Triglycerides are the chemical compound form in which we store fat.  Triglycerides look like a capital letter “E.”  They consist of a single vertical sugar backbone (the glycerol) with three horizontal tails (the fatty acids). The more starch you eat, the more glycerol molecules you make.  The more glycerol molecules you make, the more triglyceride you can create.  You cannot make triglyceride without glycerol, and glycerol comes straight from the sugar and starch that you eat.

Remember that the more sugar we eat, the more insulin we need to catch it.  The more insulin floating in our blood stream, the more triglycerides we make.  So high triglycerides are associated with a hyperinsulinemic state.  The higher the insulin levels, the higher the triglycerides.  I see high triglycerides in several kinds of patients.  They are generally people whose diets contain large amounts of 1) sweets and starches, 2) fast food, and/or 3) alcohol.  I can predict with a fair degree of accuracy whether a patient has an elevated triglyceride level by taking a quick glance at their waistline.  Remember that the high insulin state tends to cause fat deposition in the abdomen.  Another name for this condition is a “beer belly.”  Now you know why.  Beer is made from grain.  A great many people noticed the connection long before me.

Now, low HDL is bad, and high triglycerides are ugly, but the combination of low HDL and high triglycerides is downright scary.  This combination is highly associated with hyperinsulinemia and arteriosclerosis, hardening of the arteries.  Any time I see a patient with the combination of low HDL and high triglycerides, I send them for a glucose tolerance test.  I am not waiting around for them to develop the symptoms of diabetes.  I already know they are at very high risk. If there’s a problem, I want to know about it now.  They deserve to know what’s wrong, and they certainly deserve a chance to fix it before it becomes a much bigger problem than it already is.

I also know that the metabolic picture showing a combination of low HDL and high triglycerides is strongly associated with the small, dense LDL pattern.  These are not coincidental combinations.  They are a predictable consequence of eating refined, processed, fast foods.  And that means they are not so hard to fix.  So I’m not looking at each measurement in the lipid profile as an individual entity.  I’m looking at the overall pattern. And I’m not looking at the numbers as an end in themselves.  I am looking at the person who carries those numbers.

If you would like to learn more about cholesterol, sugar, and triglycerides, you can access Dr. Lustig’s first in a series of lectures at http://www.youtube.com/watch?v=dBnniua6-oM.  This is a complex topic, and it raises a great many more questions than it answers. So please feel free to post your questions, and give me the opportunity to try to answer them.  Do not worry that your questions are simple.  I can guarantee you that many people are wondering the same thing.  I may even have attended medical school with some of them.