Gettysburg Medical News
The Clinical View
By Phillip Hoffsten, M.D.
23 March 2005

Blood Cholesterol:  How Low Is Low Enough?

            There is probably no medical problem more addressed than the cholesterol level in the blood.  We are still directed by the American Heart Association to avoid high cholesterol containing foods and then comes Dr. Atkins with his high fat/protein diet saying his prescription is better than theirs.   There is little argument that no matter what the cause is, a high blood cholesterol contributes to premature heart attack and stroke.  This column will be directed to address a series of questions that seem to come up again and again in clinical practice.

            Question #1:  Where does the body’s cholesterol come from?

            Answer:  The liver makes cholesterol.  If we did not eat any cholesterol, the liver can make more than enough to satisfy the body’s needs.  If we lose a lot of cholesterol, the liver has a reserve capacity to make even more if we need it.  Normally the liver makes 1200 milligrams of cholesterol per day while an average cholesterol intake from food is about 300 milligrams per day.  People with high blood cholesterol almost always have a decreased level of cholesterol excretion and is the big difference from people with normal blood cholesterols.  A very low cholesterol diet may get down to 200 milligrams of cholesterol per day but this is rarely enough to lower a person’s blood cholesterol.  Thus, diets are an ineffective way to lower blood cholesterol.  If you like oatmeal, enjoy; but do not be fooled into believing eating oatmeal lowers the blood cholesterol.

            Question #2:  How low should the blood cholesterol be to prevent heart attacks and strokes?

             Answer:  This is where the controversy lies.  Cholesterol in the blood is present as LDL (bad cholesterol) and HDL (good cholesterol).  The HDL seems to be most determined by hereditary factors with no medication very effect at raising the HDL.  The higher the good cholesterol HDL the better to prevent heart attack and stroke.  Vigorous exercise, such as jogging 4 or more miles per day, may raise the HDL but diet and medication play little if any part in raising blood HDL levels.

            The controversy is related to what level of blood LDL (bad cholesterol) is safe.  Currently the National Cholesterol Education Panel says an LDL of 160 mg% is safe if the person has no other risk factors such as hypertension, diabetes, or cigarette abuse, and is a male under age 40 or a female under age 55.   To me this is bogus.  We know from multiple studies that the risk curve for blood LDL cholesterol is a smooth continuous line that shows a progressively lower risk down to 70 mg% LDL or less.  We know from animal studies that LDL levels of 70 mg % are required to prevent atherosclerotic degeneration in animal arteries.

            The most convincing point favoring an LDL of 70 mg% comes from a study where a number of men were facing coronary artery bypass surgery for treatment of severe coronary artery disease.  A number of these men refused a surgical solution to their problem.  They were then asked if they would be willing to try medication with one of the “statin” drugs to get their cholesterol as low as possible.  Many of them agreed to try the statin drug.  Their success was then compared to the group of men who had bypass surgery done.  The survival results were strikingly in favor of using the medication as compared to surgical result.  In addition, survival tended to be better in those individuals with the lowest LDL cholesterol.   They did not all get down to 70 mg% LDL but clearly the lower the LDL the better.

            Question #3:  What should a person do to get their LDL down and at what age should steps be taken?

            Answer:  When a person’s LDL is greater than 100 mg%, some program to lower the value should be started.  We know from war related deaths in our young soldiers that degenerative arterial disease begins when men are in their twenties.  Cholesterols only increase with age.  It just does not make sense to me to wait until someone is 50 or older to start dealing with high blood cholesterol.  Deal with the problem early in life (twenties) to prevent the problem of degenerative arterial disease from ever developing and thereby living better longer.  Having to deal with heart attacks and strokes after they happen has very, very little recreational value.  Staying healthy allows you to do the things you like that do have high recreational value.  The health care providers at your local clinic are aware of these considerations and can help screen for and treat abnormal dangerous cholesterol levels.