Low Carbohydrate Diets and CholesterolThe determination of heart disease risk based on cholesterol levels is actually a measure of how much cholesterol is being transported to body cells for use in cell walls and hormone production, as opposed to how much cholesterol is being removed from body cells for disposal. This is where we get the definitions of "good" versus "bad" cholesterol. In simplified terms, TOTAL CHOLESTEROL as measured in the laboratory on a blood sample consists of LDL or "bad" cholesterol plus HDL or "good" cholesterol. (There are other subfractions which enter into the equation, but this is the basic terminology). I have heard criticisms that a low carb diet causes an increase in cholesterol. This statement is meaningless if it means total cholesterol, because an increase in the good fraction will cause the total cholesterol to increase, but is a very beneficial effect. There is no way to know the significance of a high total cholesterol level without knowing the measures of HDL and LDL cholesterol. Criticisms about high fat intakes with low carb diets causing increased heart disease are typically based on the knowledge of studies showing exactly that effect in high carbohydrate diets (50% or more of total calories obtained from carbohydrate). It is a scientific error to ignore the difference in carbohydrate content of the diet. (This is discussed more in detail in the section on criticisms of low carb diets). The evidence for this is clear. Scientific studies that considered both the carbohydrate and the fat content of the diet (dating as far back as 1977) demonstrated that increased fat in the diet caused an increase in HDL cholesterol. The mechanism for this is the production of a protein called Apo A-I, which is a major component in the cell wall of the HDL molecule. In addition, saturated fat was shown to increase the production of Apo A-I more than polyunsaturated or monounsaturated fat. Add to this the evidence that the human body always uses dietary carbohydrates for energy before using fat, and we can see why a diet higher in carbohydrates should cause an increase in LDL cholesterol. If adequate calories are present in the carbohydrate content of a meal, then the fat in the same meal will be transported for storage. The molecules that ultimately transport the bulk of this fat is the LDL molecule. The fat itself is in the form of triglycerides, but a fairly constant amount of cholesterol is included in each LDL. It is therefore no surprise that a shift to a low carbohydrate diet that contains more saturated fat than recommended can lower LDL cholesterol and raise HDL cholesterol at the same time. Sometimes the increase in HDL is dramatic - in these instances, the total cholesterol may very well increase above normal levels - but it is a very desirable high cholesterol to have. It should be noted that there are persons who have various genetic conditions in which too much LDL cholesterol is manufactured, or is not cleared appropriately from the bloodstream. In these persons the same benefits in cholesterol measurements may not be obtained from a low carb diet, and they may require medications to lower cholesterol despite optimal dietary practices. This does not mean that the low carb diet does not work for them - it is still the healthiest way for them to eat, as long as the LDL cholesterol level is controlled. More detail about the subfractions of cholesterol and how they interact with each other and how they are influenced by diet is provided in "DIET TRUTHS REVEALED: The IDEAL DIET for Human Health". This 142-page book reveals the known scientific facts about human nutrition and metabolism in layman's terms, explaining why low carbohydrate diets are the healthiest for most people. More information about the book And you can download excerpted articles that appeared in The IDEAL DIET Newsletter between 2000 and 2003. On the topic of cholesterol, everyone should read the following: "Have you seen the new cholesterol guidelines?" Pub. 35 "Healthy cholesterol levels on a low fat diet." Pub 20 You will find many other articles that will help you understand the low carb diet and the controversies surrounding it in the media.
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Critics of Compare
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