Doctors often explain, but patients often want to re-establish the knowledge – what are triglycerides and cholesterol? What is their role in our lives?
Cholesterol and triglycerides are two types of lipids, or fats. Without cholesterol and triglycerides there is no life. Cholesterol, among other things, is needed to build cell membranes and produce a natural hormone. Triglycerides, which are high-energy fatty acid chain, provide much of the energy needed for normal functioning of cells. There are two sources of these lipids: dietary sources and endogenous sources (ie, when they are produced by the body). Cholesterol and triglycerides are found mainly in animal products and saturated fats. These lipids are absorbed in the intestines and then delivered through the bloodstream to the liver where they are processed. One of the main tasks performed by the liver is to ensure that all parts of the body get cholesterol and triglycerides, without which they can not work. The liver then packs cholesterol and triglycerides, along with special proteins, into tiny compounds called lipoproteins. Lipoproteins enter the bloodstream and thus are delivered to cells in the body. Cells then take, according to their needs, cholesterol and triglyceride from lipoproteins.
What is LDL, and what is HDL?
LDL is the “low-density lipoprotein,” and HDL “high-density lipoprotein.” “Bad” cholesterol in the bloodstream is transferred from LDL and “good” cholesterol by HDL. Most cholesterol in the blood comes from LDL, and HDL cholesterol makes up only a small part. Thus, the total cholesterol level in blood reflects the amount of LDL cholesterol.
Why is it unhealthy to have high cholesterol?
When LDL cholesterol (or “bad” cholesterol) is too high, the LDL tends to stick to the surface of blood vessels, leading to the stimulation of “atherosclerosis,” or hardening of the arteries. Atherosclerotic “plaques” narrowing of the arteries, which can cause heart attack or stroke. Because elevated LDL cholesterol is a major risk factor for heart disease and stroke.
Why is one type of cholesterol called “good cholesterol”?
There is much evidence that increased levels of HDL cholesterol is associated with lower risk of heart disease, and that low HDL cholesterol is associated with an increased risk of heart disease. This is why HDL cholesterol is called “good.” Why HDL cholesterol is protective? No one can say for sure, but it seems that cholesterol is not good in itself, it’s the “conductor”. There is evidence that the HDL molecule “scours” the walls of blood vessels, and cleans out excess cholesterol. If so, then the cholesterol that is carried by HDL (ie, what we call “good” cholesterol) is actually “bad” cholesterol that is just removed from the walls of blood vessels and is transported back to the liver for further processing.
Why are triglycerides so mysterious?
Triglycerides get little attention. They are measured in standard blood lipid profile, except that many doctors do not know what to do when triglyceride levels are modestly elevated. Why? While high levels of triglycerides associated with heart disease, no study has yet proven that high triglyceride levels are an independent risk factor for heart disease. This means that doctors have no proof that in this case need to recommend aggressive treatment to reduce levels of triglycerides in the blood. The problem is that patients with elevated triglyceride levels almost invariably have other major risk factors for heart disease (mainly obesity, diabetes, and / or high blood pressure). So, it has not been established whether the triglycerides themselves pose an independent risk. The most difficult is to define the relationship between triglycerides and HDL cholesterol. It turns out that whenever triglycerides are increased, HDL cholesterol decreases. So is the increased risk seen with high triglycerides due to the triglycerides themselves, or to the reduction in “good” cholesterol? So far, nobody can say for sure.