What You Need to Know About Cholesterol Part 1

2 mins to read

Cardiovascular disease (CVD) today remains the leading cause of death in Australia. We look at the basic facts to provide a better understanding of cholesterol's role in healthy ageing.

Heart and circulation

It is now commonly known that one of the main risk factors for the development CVD is raised blood levels of blood cholesterol. But what is cholesterol is and what does it do? Did you know that there is both ‘good’ and ‘bad’ cholesterol? Do you know how much cholesterol is considered a healthy amount?

What is cholesterol?

Cholesterol is a type of lipid or fat that is found in the foods we eat and is also produced in the body by the liver. In fact the production of cholesterol by the liver contributes more to the body’s total cholesterol than the diet.

Cholesterol functions in the body as a starting material for the production of bile salts and for steroid hormones such as testosterone, oestrogen and vitamin D. It also plays a vital role as part of the structure of cell membranes.

Cholesterol combined with other types of fat and protein to become a lipoprotein. Lipoproteins transport cholesterol around the body.

The good and the bad

Cholesterol is often spoken about in terms of ‘good’ and ‘bad’ cholesterol, but usually without a clear understanding of why one is ‘good’ and one is ‘bad’.>

High-Density Lipoproteins (HDL)

Cholesterol in HDLs is commonly referred to as ‘good’ cholesterol. HDLs pick up excess cholesterol in the body and transport it to the liver where it is readied for excretion, or to other areas of the body that are in need of cholesterol.

Low-Density Lipoproteins (LDL)

Cholesterol in LDLs is commonly referred to as the ‘bad’ cholesterol. LDLs are the main transporters of cholesterol in the body, taking cholesterol from one part of the body to another. However when we have too high a level of circulating LDL in the blood it can lead to deposits of cholesterol in the arteries, increasing the risk of atherosclerosis (hardening of the arteries) which may lead to a heart attack.

LDL cholesterol contributes to CVD as it is highly susceptible to oxidative damage by free radicals. The process in which the LDL are damaged seems to be a cyclical one whereby the excess LDL accumulated in the arteries undergoes oxidative damage and then the damaged LDL attracts white blood cells which cause yet more damage to the LDL. This damage can lead to the formation of plaques in the arteries which can restrict blood flow and increase the risk of CVD.

Very Low-Density Lipoproteins (VLDL)

Are made in the liver and transport fat and cholesterol around the body. VLDL become LDL after they have delivered their fat load to its destination.

The Cholesterol Test

Cholesterol is measured by a blood test which may be ordered following a consultation with your healthcare professional. Generally you will be tested if you have previously diagnosed heart disease, a family history of high cholesterol or you are over the age of 45. A lipid profile test is usually taken which looks at not only your total cholesterol, but also your LDL-, HDL- and VLDL-cholesterol levels and the ratio of LDL:HDL-cholesterol. As a general rule, total blood cholesterol of more than 5.5 mmol/L is an indicator for increased risk of CVD. Your results however should always be discussed with your healthcare professional who will look at the results as part of an overall risk along with other factors.

Did You Know?

Women tend to have higher HDL cholesterol than men?

In part 2 on the facts about cholesterol, we discus how to manage healthy cholesterol levels with a healthy diet and lifestyle