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What is Cholesterol?

Cholesterol is a soft waxy substance found in every cell of your body and helps to maintain your nervous system, skin, muscles, liver, intestines and heart.

The word cholesterol can refer to one of two things: the cholesterol found in the body (blood cholesterol) or the cholesterol found in foods (dietary cholesterol). Throughout the website, when you see the word ‘cholesterol’, it’s referring to blood cholesterol. When you see the term ‘dietary cholesterol’, it’s referring to the cholesterol found in foods.

What is cholesterol used for?

People often think that all cholesterol is bad for you. But cholesterol plays an important role in keeping your body healthy. It is used to build cell walls and to produce vitamin D, digestive juices and many hormones. Your body simply cannot function properly without a certain amount of cholesterol.

Where does it come from?

If you’re like most people, you probably think that the cholesterol in your bloodstream comes from dietary cholesterol. But in fact, dietary cholesterol has just a small impact on your blood cholesterol levels. The majority of your blood cholesterol is naturally produced by your liver and the remaining is absorbed into your body from foods that contain dietary cholesterol.

Dietary cholesterol is found in foods of animal origin, such as dairy products, egg yolks, poultry, red meat and certain types of shellfish. Foods that come from plants, such as grains, fruit and vegetables, can contain trace amounts of dietary cholesterol.

Dietary cholesterol does not increase risk of heart disease

Dietary cholesterol is one of the most misunderstood types of cholesterol. Some people limit eggs and other foods that contain dietary cholesterol because they are concerned about increasing their blood cholesterol levels. But major studies have shown that dietary cholesterol has very little effect on blood cholesterol in healthy adults.2,3

Experts agree that the cholesterol absorbed from food does not increase risk of heart disease.1,4

Did You Know?

Your body performs a delicate balancing act to keep your blood cholesterol at a healthy level. If you eat foods that are high in cholesterol, your body naturally compensates by reducing the amount of cholesterol produced by your liver.

If you don’t get much cholesterol from your diet, then your liver increases cholesterol production to meet your body’s needs.

Is cholesterol a health concern?

Cholesterol is not a health concern if you maintain healthy blood cholesterol levels. However, too much cholesterol in your bloodstream has been linked to serious health problems, such as heart disease, stroke and diabetes.

Talk to your doctor about getting your blood cholesterol levels checked and how often you should be tested. Browse our ‘Talk to your doctor’ section for more information on risk factors for heart disease.

What causes high blood cholesterol?

The causes of high blood cholesterol are complex. There are many factors that can affect your cholesterol levels.  Some you can control while others you cannot control. Your family history, age and even your gender can put you at risk for high cholesterol and are factors you cannot control. Things like your diet and physical activity levels are factors that you can control.

Talk to your doctor about your risk factors for high cholesterol and their impact on your long-term health.

Did You Know?

A large, long-term study showed that people who ate 5 or more eggs a week had a lower risk of heart disease than people who ate less than 1 egg per week.

Types of Blood Cholesterol

There are actually several different types of cholesterol circulating in your bloodstream and most of them are produced by your liver. Some types of cholesterol are good for you and others can be harmful.

Understanding the different types of cholesterol and their role in the body will help you make the right decisions about managing your cholesterol levels.

Good and Bad Cholesterol

The terms “good” and “bad” cholesterol refers to the cholesterol found in your blood. Cholesterol travels through the bloodstream attached to certain proteins. This combination of cholesterol and protein is called a lipoprotein.

There are two main types of lipoproteins:

HDL or “Good” Cholesterol LDL or “Bad” Cholesterol
High-density lipoproteins or HDL cholesterol is known as the “good” cholesterol because it removes LDL “bad’ cholesterol from your blood and carries it back to the liver, where it is eliminated as waste. This helps prevent plaque from building up in your arteries. Keeping your HDL levels high helps protect your heart. Low-density lipoproteins or LDL cholesterol is known as the “bad” cholesterol because having too much LDL in your blood can build up on the walls of your arteries, forming deposits called plaque. Plaque deposits can narrow your arteries, a process called atherosclerosis. Plaque can also break off from the artery walls, forming blood clots that may cause heart attack, stroke or sudden death. Your goal should be to keep your LDL levels low.


Triglycerides are the most common type of fat found in the blood. They are produced in the body – your liver changes excess calories from fat, carbohydrates and proteins into triglycerides. People who are very overweight, eat a lot of fatty and sugary foods, or drink too much alcohol are more likely to have high triglyceride levels. The connection between triglycerides and heart disease is not clear but people with high cholesterol, heart disease and diabetes often have elevated triglyceride levels.