Cholesterol and healthy living

What is cholesterol?

 The word “cholesterol” can refer either to the cholesterol found in the body (“blood cholesterol”) OR  the cholesterol in food (“dietary cholesterol”).  In this booklet, for the sake of easy reading, we’ll use “cholesterol” to mean “blood cholesterol,” in other words, the cholesterol in your body. When we talk about the cholesterol in food, we’ll use the term “dietary cholesterol.”

Cholesterol is a soft waxy substance made by our bodies. It is one of the lipids (fats) normally found in the blood and every cell of the body. We often associate cholesterol with health problems. In fact, cholesterol is a vital building block of cell membranes, hormones and vitamin D. Without it, your body couldn’t function.

Sometimes, however, the body produces too much cholesterol. This is a major risk factor for atherosclerosis, also known as hardening of the arteries.

In atherosclerosis, a sticky substance called plaque builds up on the insides of arteries (blood vessels that carry blood from the heart to different parts of the body). This build-up slowly clogs the arteries and damages their lining. The major component of plaque is cholesterol. As the arteries narrow and become damaged, the risk of circulation problems, heart attacks and strokes rises.

Where does cholesterol come from?

 About 80 percent of the cholesterol in our bodies is made by the liver. The other 20 percent comes from animal-derived foods such as eggs, milk products, meat and poultry. Eating foods high in cholesterol can raise blood cholesterol levels in some people. However, foods that contain a lot of fat, especially saturated fat and trans fat, have the most significant impact on our cholesterol levels.

Choosing foods that are lower in fats, especially trans and saturated fats, is a very effective way to control cholesterol. We’ll discuss the different kinds of dietary fats and their role in your diet a little later on in this booklet.

Lifestyle and cholesterol levels

 Adopting a healthy lifestyle is an important first step towards achieving and maintaining healthy cholesterol levels. In this booklet, we’ll outline lifestyle changes that can help you manage your cholesterol levels and lower your risk of cardiovascular disease. The basics of cholesterol management include:

• Eating a diet that is lower in fat, especially saturated and trans fats, and includes a variety of fruits, vegetables and whole grains;
• Being physically active, and accumulating 30 to 60 minutes of moderate physical activity most (or all) days of the week;
• Achieving and maintaining a healthy weight;
• Limiting alcohol intake;
• Being smoke-free.

Understanding lipoproteins

 Cholesterol is carried through the body by the blood, in tiny cholesterol-protein packets called lipoproteins. Lipoproteins come in two varieties:

1) low-density lipoproteins or LDL cholesterol and

2) high-density lipoproteins or HDL cholesterol.

To understand the results of cholesterol testing, we need to understand the difference between these two.

The first, LDL cholesterol, is known as "bad" cholesterol.  While our bodies need normal amounts of LDL cholesterol for cell growth and repair, high levels of LDL cholesterol are responsible for the buildup of plaque in the arteries.

The second, HDL cholesterol, is known as "good" cholesterol because it helps move cholesterol out of the blood and to the liver where it is processed. 

Triglyceride – the most common fat in the body

 Another type of fat called triglyceride is usually measured when your cholesterol is tested. Triglyceride is not cholesterol. However, it is the most common form of fat in our bodies. It seems to have some effect on heart disease, although the exact relationship is not yet clear. Although triglycerides do not stick to the walls of the arteries, they may increase the tendency of the blood to clot. The greater the tendency to clot, the greater the risk of a heart attack or stroke.

High triglyceride levels are associated with excess intake of saturated fats, trans fats and alcohol. They are also linked to excess body weight and poorly controlled diabetes.

A question of balance

 All blood lipids (fats) have a role within the body. The key to good health is maintaining a proper balance between them. In the next several pages, we’ll see how blood lipids are measured and what levels of each are considered healthy.