Cholesterol

We have selected the following expert medical opinion based on its clarity, reliability and accuracy. Credits: Sourced from the Cleveland Clinic, Ohio. Please refer to your own medical practitioner for a final perspective, assessment or evaluation.

Overview

What is cholesterol?

Cholesterol is a soft, fat-like, waxy substance only found in animal products. Too much cholesterol leads to a build-up of fatty materials and debris (called plaque) on the walls of the arteries supplying blood to the heart and other organs. Some cholesterol is needed by the body. In fact, cholesterol plays a role in normal body functions, including the formation of cell walls, production of hormones, and manufacture of bile acids, which are needed for digestion. Because the liver has the ability to make all the cholesterol our bodies need, there is no need for extra cholesterol in the diet.

What is total blood cholesterol?

Your total blood cholesterol is a measure of the cholesterol components LDL (low-density lipoprotein) cholesterol, HDL (high-density lipoprotein) cholesterol, and VLDL (very low-density lipoprotein, which is the triglyceride-carrying component of lipids). Total cholesterol values cannot be interpreted in the absence of the cholesterol components listed below.

What are the kinds of cholesterol?

LDL (low density-lipoprotein) cholesterol is also called "bad" cholesterol. LDL can build up on the walls of your arteries and increase your chances of getting heart disease.

HDL (high-density lipoprotein) cholesterol is also called "good" cholesterol. HDL protects against heart disease by taking the bad cholesterol out of your blood and keeping it from building up in your arteries.

Triglycerides are the chemical form in which most fat exists in food and the body.

What affects cholesterol levels?

A variety of factors can affect your cholesterol levels. They include:

Diet: Saturated fat, trans fat and cholesterol in the food you eat increase cholesterol levels. Try to reduce the amount of saturated fat, trans fat and cholesterol in your diet. This will help lower your blood cholesterol level. Saturated fat and trans-fat have the most impact on blood cholesterol.

Weight: In addition to being a risk factor for heart disease, being overweight can also increase your triglycerides. Losing weight may help lower your triglyceride levels and raise your HDL.

Exercise: Regular exercise can lower total cholesterol levels. Exercise has the most effect on lowering triglycerides and raising HDL. You should try to be physically active for 30 minutes on most days.

Age and gender: As we get older, cholesterol levels rise. Before menopause, women tend to have lower total cholesterol levels than men of the same age. After menopause, however, women's LDL levels tend to rise, and HDL can drop.

Heredity: Your genes partly determine how much cholesterol your body makes. High blood cholesterol can run in families.

Common misperceptions

True or False?

The lower my cholesterol, the lower my risk for heart disease.

True and false: The statement above is true. According to the statistics, your risk for heart disease is lower when you have low total cholesterol and low LDL (low density lipoprotein) cholesterol. LDL cholesterol is the fatty substance that is most related to arterial blockage.

The statement above is also false. Your risk for heart disease is actually higher if you have a low HDL (high-density lipoprotein) cholesterol level. HDL is the "good" cholesterol; it carries fat out of the coronary arteries.

If a product's package reads "low cholesterol," it is low in fat and safe to eat.

False: A lot of foods marked "low cholesterol" contain oils that may be high in saturated fats and transfats, substances that research suggests may be as bad if not worse for you as cholesterol. Unsaturated fats, such as vegetable oils, are also high in calories.

Remember, all fats are high in calories — 1 gram of fat has 9 calories. Protein and carbohydrate each have 4 calories per gram. It's true that we all need some fat in our diets.

Unsaturated fats are considered the healthiest fats because they improve cholesterol levels, help reduce inflammation (a risk factor for heart disease) and help decrease the overall risk of developing heart disease. The main source of unsaturated fats is plant-based foods. Of the unsaturated fats, monounsaturated fats are one of the healthiest, and include fats such as olive oil, canola oil, peanut oil, most nuts, nut butters, seeds, olives and avocados. Monounsaturated fats do not increase blood cholesterol when included in a low-fat meal plan.

Other unsaturated fats include polyunsaturated fats with sources that include: corn oil, soybean oil, safflower oil, flax, sunflower, walnuts, and fish.

The total amount of fat in your diet should be about 25-35% of your daily intake (or 1 tbsp. of the fats listed above, per meal).

The best age to have my cholesterol level checked is age 50 because that's the peak age for heart attacks in men.

False: It is important to have your cholesterol level checked when you are young, since the process of arterial clogging (called atherosclerosis) is a gradual one and takes many years. Heart attacks that occur in people age 50 and above may be the result of plaque that began to form on the inside of their coronary arteries when these people were teenagers.

Total cholesterol should be measured at least every 5 years starting at age 20. If your cholesterol levels are within the normal range and you do not have other risk factors for heart disease, you can continue getting tested every 5 years. If your cholesterol levels are too high, you should talk with your doctor about making lifestyle changes or taking medication. You and your doctor should also discuss a re-testing schedule.

Note: If you have high cholesterol and your doctor has told you there may be an underlying genetic cause, you may want to have your children, under age 20, get their cholesterol levels tested. Talk with your children's healthcare providers about cholesterol testing.

Cholesterol is the only risk factor for cardiovascular disease that I should worry about.

False: There are several other important risk factors that predispose you to cardiovascular disease. The good news is that most of these risk factors can be changed by making small modifications in your lifestyle. Cigarette smoking is by far one of the strongest risk factors for cardiovascular disease. However, your risk is drastically reduced after 1 year of not smoking. After 4 years of being smoke-free, your risk for cardiovascular disease is equivalent to that of a non-smoker.

Other risk factors for cardiovascular disease include physical inactivity, diabetes, uncontrolled high blood pressure, and obesity.

The following guidelines may help you prevent the development and/or progression of cardiovascular disease:

• Add 30 minutes of moderate exercise most days of the week
• Lower the amount of fat in your diet to under 35% of your intake
• Manage your high blood pressure, diabetes, and other medical conditions

Since both of my parents died from coronary disease when they were young, there's little I can do to prevent this disease from developing in me.

False: While your family history is an important risk factor (and not changeable), you can control your risk of developing cardiovascular disease by controlling high cholesterol (through diet and sometimes medication), quitting smoking, managing high blood pressure and diabetes and exercising regularly. In fact, recent research shows that you can stop or reverse the progress of atherosclerosis by following a very strict risk factor modification program.

Because atherosclerosis is a slow, gradual process that probably starts in childhood, it is important to have your cholesterol levels tested at age 20. Those who have a strong family history of heart disease should be even more vigilant in testing their cholesterol levels.

A strong family history is:

• Having a first-degree male relative who had a heart attack, angioplasty, or bypass under age 55.
• Having a first-degree female relative who had an angioplasty, heart attack, or bypass under age 65.

Fact summary

Twelve million Americans have coronary artery disease, making it the leading cause of death in this country.

More than 90 million adults have cholesterol levels that are higher than desirable.

High blood cholesterol is a major risk factor of coronary artery disease, but one that is also quite modifiable.

• Lowering your cholesterol level by 1% lowers your risk for heart disease by 2%.
• For some people, losing excess weight will lower total blood cholesterol levels.
• Egg yolks and organ meats, such as liver, are the foods highest in cholesterol. (One egg yolk has 213 milligrams of cholesterol.)

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