My recent post, Saturated (Animal) Fat Does Not Cause Heart Disease has generated numerous e-mails and comments that seem to focus on the connection between our dietary cholesterol intake and the fact that vascular plaques that lead to arterial blockage also contain cholesterol.
One read wrote, “If dietary fat intake doesn’t lead to increased cholesterol which clogs coronary arteries and causes heart attacks, then what is clogging arteries? It must be something. Otherwise, bypass surgeries wouldn’t be effective but they are.”
Considering the fact that the U.S. government and most large health organizations have been promoting the connection between dietary cholesterol intake and vascular disease, it quite understandable that readers may find my post a bit confusing. Unfortunately as I pointed out in my post, critical independent reviews of past research studies do not support the conclusions of the authors of the original research promoting the concept of low fat diets preventing heart and vascular disease.
There are many factors involved in the low fat debacle but the most important has probably been that many of those who consistently promoted the concept where the very same individuals and organizations who benefited financially from the government funds that were paying for the research being conducted. I am not saying individuals purposely mislead the public but many believe they may of been overly invested in the concept of low fat to consider alternative explanations for heart disease.
Why then is cholesterol present in the arterial plaques if dietary cholesterol intake has nothing to do with it? We are beginning to understand that the metabolic phenomena known as Insulin Resistance is responsible for a great majority of the vascular narrowing that leads to strokes and heart attacks and that the fundamental process involved is inflammation of the cells that line the blood vessels and not an excessive abundance of cholesterol in the diet. Insulin Resistance involves many complex metabolic pathways that have yet to be fully described but the mounting evidence is pointing to the excessive consumption of carbohydrates as the primary culprit with obesity as a strong secondary factor. It is not understood why some cholesterol is present within these arterial plaques but mounting evidence suggests the cause is something other than dietary cholesterol.
An additional confusing factor is the fact that there are many types of cholesterol in the blood stream and that not all are harmful. When the theory that eating saturated fat raised cholesterol levels was proposed in the 1950’s and 60’s, scientists were only able to measure ‘total cholesterol’. Total cholesterol is combined measurement of LDL, HDL and VLDL cholesterol’s as well as triglycerides. The inability to more closely follow the changes of each specific type of fatty molecule has lead to false and contradictory conclusions in much of the early research.
Even the modern classification of ‘good’ (HDL or high density lipoprotein) cholesterol and ‘bad’ (LDL or low density lipoprotein) is changing with recent understanding that there are at least 3 and possibly 5 different types of LDL cholesterol. Interestingly some of these LDL subtypes are strongly associated with damage to blood vessels (small-dense LDL molecules that are associated with high carbohydrate intake) while others subtypes are not (large-fluffy LDL molecules that are often found with lower carbohydrate intakes).
Additionally, there is still much research needed to clarify the role of saturated versus monounsaturated fats in our health but one factor is clear, high carbohydrate dietary intake has a extremely unhealthy effect on our bodies. So instead of having my patients chase the unhealthy low fat diet strategy (low fat diets often lead to an increase in carbohydrate intake by as much as 20-30%), I teach them they have the ability to stop and even reverse much of the harm from carbohydrates and Insulin Resistance by simply reducing theircarbohydrate intake to less than 150-200 grams of carbohydrates per day (about 25-30% of a individuals daily calorie intake).
Focus on carbohydrates for some immediate improvement in your health and try to insure your getting enough protein in your diets to maintain adequate amounts of muscle.