What is cholesterol?

Understand the different types of cholesterol and how they affect your heart health. 

Lucy E. Cousins
December 2018

When Henry Jackson felt a sudden pain in his shoulder, he dismissed it as a muscle strain.

“I was playing golf with some mates of mine. I waved it off but when I got home my wife told me to go to the doctor,” explains Jackson, 62.

Jackson’s doctor told him he had high cholesterol and he was at risk of heart attack.

“It turned out I needed 2 stents [a tube to open my arteries] put in, which gave my family and myself a bit of a scare.”

For Jackson, the operation was a wake-up call. Recently retired, he was a lover of “good wine and fine food”. While he enjoyed the occasional game of golf, he wasn’t exercising enough. After the procedure he overhauled his diet, cut down on wine and started working out with a personal trainer 2­-3 times a week.

“My personal trainer knows what kind of exercise I should be doing as I recover. It’s been hard but I want to be around for my grandkids, so it’s worth it,” he says.

What is cholesterol?

Cholesterol is a fatty substance your body produces naturally and carries in the blood.

“Cholesterol is 1 of the types of fat that’s used by your body. Your liver breaks down this fat into its component fatty acids and then repackages them up into different fats,” says GP Dr Ginni Mansberg. 

Your body needs these fats. Without a fat coating around every single nerve, they won't function efficiently.

Your body also uses cholesterol as a major component of all cell membranes. It’s required to create some hormones, and acids to help with digestion. 

Where does cholesterol come from?

Your body makes most of the cholesterol it needs. Cholesterol in food (in eggs for example) doesn’t have a big impact on the cholesterol in your blood. What does is saturated and trans fats, reports the Heart Foundation.

These are found in:

• visible fat on meat and chicken
• processed meat
• palm and coconut oil
• processed foods like biscuits and cakes
• cheese and butter
• deep-fried food.

Why is high cholesterol a problem?

High cholesterol is a leading risk factor for heart disease, according to The Heart Foundation.

So “lowering your cholesterol levels can go a long way towards improving your future heart health”, says CEO of The Heart Foundation, Adjunct Professor John Kelly.

Having high levels of cholesterol can also put you at risk for a range of other health issues, including stroke, diabetes and vascular (artery) disease.

As 1 in 3 Australian adults has high cholesterol, it’s important to understand the risk factors and when you should get your levels tested.

How do I measure my cholesterol levels?

Your GP can do a blood test that measures your:

• total cholesterol
• low-density lipoproteins (LDL)
• high-density lipoproteins (HDL)
• triglycerides.

LDL is sometimes called ‘bad’ cholesterol because it can clog your arteries.

HDL doesn’t tend to block arteries and is referred to as ‘good’ cholesterol.

Total cholesterol is the total amount of ‘good’ cholesterol and ‘bad’ cholesterol in your body, as well as triglycerides (the result of your body converting calories into fat).

The cost of cholesterol tests vary but you may get a rebate from Medicare.

Home tests for cholesterol vary in accuracy and don’t give you reliable information on your risk of heart disease.

How often should I get tested?

How often you should get your cholesterol tested depends on your age, lifestyle, family history and previous blood test results. 

“The Heart Foundation recommends that all adults should have a regular cholesterol check and speak to their doctor about their cholesterol levels, especially if you are a smoker, have diabetes, or if heart disease runs in their family,” says Adj Prof Kelly. A cholesterol test is also recommended if you have high blood pressure.

The Heart Foundation recommends people over 45, or over 35 for Aboriginal or Torres Strait Islander people, get a cholesterol test as part of a heart health check every 5 years.

How do I lower my cholesterol levels?

High cholesterol can be treated with medication, but Dr Mansberg says it’s important to make sure the benefits of medication outweigh the risks.

She points out that some cholesterol medicine, namely statins, can slightly increase the risk of type 2 diabetes, and can cause muscle pain. If you’re worried about side effects, speak to your doctor.

Lifestyle changes can help lower the cholesterol level in your blood. Studies show that one of the most effective dietary strategies for lowering cholesterol is to eat more plant sterols, found in vegetables, nuts, seeds and some fruit.

You can also find foods fortified with plant sterols, including milk and yoghurt.

As well as eating a balanced diet low in saturated and trans fats, salt and added sugar, and high in whole grains, fibre and unsaturated fat, The Heart Foundation recommends people with a high risk of heart disease have 2-3g of plant sterols a day to lower cholesterol.

Regular exercise and quitting smoking can also help to control cholesterol.