Cholesterol

What is it?

Cholesterol is a waxy, fatty substance found in the bloodstream and in all your body's cells. Cholesterol has an important role to play because it is required to form part of cell membranes and certain hormones, however, too much of it is unhealthy. Our livers produce some cholesterol, and we obtain the rest from the foods we eat.

Cholesterol cannot dissolve in the blood and therefore needs to be transported to and from cells by special transporters called lipoproteins. These Lipoproteins are made up of lipids (fats) and proteins.

Let's look at the components of cholesterol in more detail.

HDL - High Density Lipoprotein - this is often referred to as the "good" cholesterol because it picks up some of the cholesterol deposited along the walls of your arteries, and transports it back to the liver where it is broken down and removed from the body. One would have a lower risk for heart disease if the HDL is high.

LDL - Low Density Lipoprotein - is known as the "bad" cholesterol. Excess LDL, deposits cholesterol along the walls of the arteries. This places the individual at risk, because the arteries can become so blocked up, that blood can no longer flow through them. If any of the arteries leading to the heart becomes blocked, a heart attach will take place, or a stroke if the arteries in the brain are affected. Therefore, a high level of LDL reflects an increased risk for heart disease.

What is normal

Cholesterol levels increase with age. For example, if you are 20 years old, your cholesterol value should be less than 4.0, and if you are 50 years old, it should be less than 5.5. However, the general guideline is that your cholesterol level should be less than 5.2 mmol per litre.

According to the latest research and the Heart Foundation of South Africa, SATURATED FAT in the diet is the most important cause of elevated cholesterol. Saturated fats are animal fats - these fats are solid at room temperature. Foods that contain saturated fats are butter, cream, full cream dairy products, cheese, beef, lam, tongue, duck, egg yolk, brains, caviar, giblets, kidneys, liver, prawns, shrimps, calamari, coconut and palm kernel oil.

What are the consequences of an elevated cholesterol

An elevated cholesterol level increases ones risk for developing heart disease and strokes. Many deaths related to heart disease occur as a result of the narrowing of the arteries, in a condition known as atherosclerosis. Athlerosclerosis occurs when the quantity of fat builds up along the walls of the arteries is so thick, that the blood flow is reduced or stopped. Some of the hardened plaque may break off which also results in a heart attack or a stroke, depending on whether this "chip" travels to the arteries of the heart or brain.

LDL is a measure of your risk for atherosclerosis as it is part of the fats that line the walls of the arteries. Therefore, reducing your LDL will reduce your risk of developing athlerosclerosis.

How do I know what my cholesterol level is

There are no symptoms for elevated cholesterol, as one would expect with flu for example. There are a few signs of markedly elevated cholesterol such as white circles around the pupils, nodules on the fingers, buttocks and eyelids. The only way to know one's exact cholesterol level is to have a blood test.

Cholesterol is measured using one of two tests:

1. The first test is merely a screen, and is a finger prick test. Only one drop of blood is analysed by a portable machine. The result obtained represents the total cholesterol in the blood. Should this value indicate an elevated cholesterol, you must have a full blood cholesterol test, known as a lipogram.

2. The lipogram is the second cholesterol test and is done after a 10 hour fast. The results obtained from this analysis is more detailed than the pin prick test. The cholesterol is broken down into the HDL and LDL components. Therefore a lipogram will give the total cholesterol, HDL and LDL and triglyceride readings.

More on... contributing factors:

• Your genes may cause you to have cells that do not remove the excess LDL from the blood vessels efficiently, or your liver may produce too much cholesterol naturally.
• Smoking may lower HDL levels by as much as 15%. Therefore if you stop smoking, your HDL may return to a higher level.
• By decreasing the amount of saturated fat in one's diet, the LDL cholesterol levels may be reduced.
• Regular exercise increases the HDL cholesterol ("good" cholesterol) and decreases LDL ("bad" cholesterol). HDL can be increased by as much as 20-30%!
• Diabetes may result in an increase in triglycerides and a decrease in HDL. If one has diabetes, it is therefore important that dietary fat intake should be regulated and a supervised / monitored exercise programme introduced.
• As you get older, your cholesterol levels may increase. This increase may be due to a general increase in body fat.

What are contributing factors to having an elevated cholesterol:

• Genetics - one can inherit the tendency to have elevated cholesterol from one's family.
• Smoking
• A diet high in saturated and animal fat
• Low levels of physical activity
• Age - the older you get, the greater the risk for elevated cholesterol.
• Gender - males are at a higher risk than females. Females have a hormone called estrogen that protects them from having an elevated cholesterol. Once menopause is reached, the estrogen is reduced and the protection is no longer present, unless the woman is taking hormone replacement therapy.