What is high blood cholesterol level? It’s a question you hear everywhere, from family gatherings to television commercials. Though awareness of the dangers of high cholesterol has greatly increased in the past two decades, there are still many myths out there. The biggest myth, although it is gradually being dispelled, is that all cholesterol is created equal. In reality, as many people are beginning to understand, the cholesterol in our blood is carried in several different particles–the main ones being high-density lipoproteins (HDL) and low-density lipoproteins (LDL). These two types of particles have completely different effects on blood vessels and their likelihood of getting clogged. Put simply, HDL protects your body from heart disease, while LDL can cause it. That’s why two patients might have totally different levels of risk for heart disease, despite having the same cholesterol level.


So what is high cholesterol? High cholesterol is a serious health problem that affects about fifty million Americans. It’s a major risk factor for cardiovascular disease (CVD), which half of all men and a third of all women will get at some time in their lives. When you’re talking about high cholesterol, what matters most isn’t your total cholesterol level–it’s the breakdown of how that cholesterol is carried. Even individuals with total cholesterol levels below 200–long considered a “safe zone”–can be at high risk of heart disease if they carry too little cholesterol in the HDL particles or have other risk factors that predispose them to the blocked arteries that cause heart attacks.


Cholesterol is a fat or lipid. It is also a sterol, from which steroid hormones are made. If you held cholesterol in your hand, you would see a waxy substance that resembles the very fine scrapings of a whitish-yellow candle. Cholesterol flows through your body via your bloodstream, but this is not a simple process. Because lipids are oil-based and blood is water-based, they don’t mix. If cholesterol were simply dumped into your bloodstream, it would congeal into unusable globs. To get around this problem, the body packages cholesterol and other fats into minuscule protein-covered particles called lipoproteins ( lipid + protein ) that do mix easily with blood. The proteins used are known as apolipoproteins. The fat in these particles is made up of cholesterol and triglycerides and phospholipid, which helps make the whole particle stick together.


So how cholesterol and heart disease are connected and what you can do to optimize your cholesterol levels. While too much cholesterol can be harmful, just the right amount of it does a lot of important work in the body. But like carbohydrates in recent years, cholesterol has gotten such a bad rap that most people don’t know the good it does.
Cholesterol performs three main functions:

1. It helps make the outer coating of cells.
2. It makes up the bile acids that work to digest food in the intestine.
3. It allows the body to make Vitamin D and hormones, like estrogen in women and testosterone in men.
Without cholesterol, none of these functions would take place, and without these functions, human beings wouldn’t exist.


The two main types of lipoproteins important in a discussion on heart disease are low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Though the names sound the same, these two particles are as different as day and night. The differences stem from their densities, which are a reflection of the ratio of protein to lipid; particles with more fat and less protein have a lower density than their high-protein, low-fat counterparts.


In most people, 60 to 70 percent of cholesterol is carried in LDL particles. LDL particles act as ferries, taking cholesterol to the parts of the body that need it at any given time. Unfortunately, if you have too much LDL in the bloodstream, it deposits the cholesterol into the arteries, which can cause blockages and lead to heart attacks. That’s why people refer to LDL as the “bad” cholesterol. The good news is that the amount of LDL in your bloodstream is related to the amount of saturated fat and cholesterol you eat. So, most people can decrease their LDL if they follow a reduced-fat diet. When you get a fasting cholesterol test, your doctor should test for the level of LDL cholesterol.


HDL is basically the opposite of LDL. Instead of having a lot of fat, HDL has a lot of protein. Instead of ferrying cholesterol around the body, HDL acts as a vacuum cleaner sucking up as much excess cholesterol as it can . lt picks up extra cholesterol from the cells and tissues and takes it back to the liver, which takes the cholesterol out of the particle and either uses it to make bile or recycles it. This action is thought to explain why high levels of HDL are associated with low risk for heart disease. HDL also contains antioxidant molecules that may prevent LDL from being changed into a lipoprotein that is even more likely to cause heart disease.


Cholesterol is so important to the body that it makes it itself. So even if you ate a completely cholesterol free diet, your body would make the approximately 1,000 mg it needs to function properly. Your body has the ability to regulate the amount of cholesterol in the blood, producing more when your diet doesn’t provide adequate amounts. The regulation of cholesterol synthesis is an elegant process that is tightly controlled.

Your blood cholesterol level is determined by the sum of how much cholesterol your body makes and how much you take in from food, minus how much your body uses up or excretes. High cholesterol can result from a problem in any of the variables in that equation—your body may produce more cholesterol than it needs due to a genetic predisposition, you may be getting too much from your diet, or you may not excrete cholesterol in your bile efficiently. The fact that Americans have higher blood cholesterol levels than citizens of the Far East or Africa could be due to differences in genetic factors, but most evidence suggests that our higher cholesterol levels are largely a product of our high-fat, high-cholesterol diet.


Lifestyle changes affect HDL levels—exercise and walk can increase HDL and decrease LDL levels, while obesity and smoking may increase LDL. As for diet ,in general, the high-fat diets that raise LDL also raise HDL, while low-fat diets lower both. However, by carefully choosing the right foods, you can eat a diet that lowers LDL without lowering HDL.


Your body does need food to fuel the cholesterol production process, but it can be virtually any kind of food, even the cholesterol-free kind. As long as the food contains carbon–which carbohydrates, fats, and proteins all do—it provides the body with the building blocks to make its own cholesterol. Cholesterol is made out of the carbon that is recycled from the food you eat. Saturated fats, however, raise blood cholesterol levels more than other types of food, which is why people watching their cholesterol are told to avoid them. This is true even if saturated fat (which doesn’t have any cholesterol in itself but is often found in foods with high cholesterol) is eaten in a cholesterol-free food. Why saturated fat does this is still something of a biological mystery.


Most people are vaguely familiar with the terms saturated and unsaturated fat. But what do they really mean? All fats have a similar chemical structure: a chain of carbon atoms bonded to hydrogen atoms. What differs is the length and shape of their carbon atoms and the number of hydrogen atoms. These slight structural differences create crucial differences in how the body reacts to them. We leave the details for some other time, but for now, here’s a primer:


The word saturated here refers to the number of hydrogen atoms these fats have. The chain of carbon atoms that makes up these fats holds as many hydrogen atoms as possible, so they’re saturated. Saturated fats are unhealthy.


These have fewer hydrogen atoms and are healthy for you. There are two different kinds of unsaturated fats: polyunsaturated and monounsaturated. Polyunsaturated fats, like omega-3 fats and omega-6 fats, have four or more carbons that are not saturated with hydrogens.


There are a variety of genetic disorders that affect how the body makes lipids. It doesn’t matter if your high cholesterol is caused by problematic genes or not. Medication and lifestyle changes are still prescribed based on your HDL and LDL levels. A family history of heart troubles can increase anyone’s risk for heart disease so light exercise and dietary changes are recommended to control obesity and high LDL.


For most people—especially those with high cholesterol—the liver and other cells aren’t the body’s only sources of cholesterol. Our society’s typical high-fat diet also packs a powerful cholesterol punch. How can cholesterol from a hamburger and French fries eventually make its way to your heart’s arteries? As you eat food with cholesterol, your intestines go through a complex process of breaking down fat molecules and building them into new molecules that the body can use. Intestinal enzymes rapidly dismantle the long, complex fat molecules into their component fatty acids, reassemble them into new triglyceride molecules, and package these new triglycerides— along with a small amount of cholesterol—into chylomicrons, a lipoprotein that has a very, very low density. So avoid junk food and food with high fat contents to control your cholesterol level.


Although LDL is thought to be the major cholesterol-carrying culprit causing heart disease, the precise form LDL must take to set off atherosclerotic plaque formation remains a bit of a mystery, but the link between high LDL levels and coronary disease is firmly established.

All patients with coronary artery disease need to exercise and to discuss the progress of their exercise program regularly and in detail with their physicians. Aerobic exercise, such as walking, bicycling, or swimming, can help you lose weight or maintain a normal weight and increase the amount of work you can do with less strain on your heart. You’ll also need to follow a heart-healthy diet, use strategies to control stress, and—it almost goes without saying—do not smoke.