Fats and cholesterol | Health prevention series

Fats and cholesterol: What are they?

Fats and cholesterol are essential nutrients that play a number of important roles in our bodies. These include giving our cells their structure, being a source of energy, and carrying vitamins around the body.¹

Different types of fats are found in the food that we eat. The healthier fats include monounsaturated fats and polyunsaturated fats (omega-3 and omega-6).³ The unhealthier fats are the saturated fats and trans fats.⁴

Cholesterol is an important type of fat that is carried in the blood. About 75% of the cholesterol in our bodies is made by our liver. The rest – about one quarter – comes from the food we eat.⁵

Fats, cholesterol & our health

Both saturated fats and trans fats are linked with a greater risk of heart disease and high blood cholesterol (or more specifically, an increase in ‘bad’ cholesterol’ – see below).²

On the other hand, the unsaturated fats – polyunsaturated and monounsaturated – are an important part of a healthy diet. These lower the risk of heart disease and cholesterol levels.²

There are two types of cholesterol found in our bodies: HDL cholesterol (the ‘good’ cholesterol) and LDL cholesterol (the ‘bad’ cholesterol). HDL cholesterol helps to prevent cholesterol building up in the arteries. LDL cholesterol, conversely, is the main cause of cholesterol build-up in the arteries.7 It was once believed that eating too much cholesterol-containing food was the main cause of high blood cholesterol. Today, however, we know that eating too many foods containing higher amounts of the unhealthy fats (saturated and trans fats) is a bigger problem and has a far bigger effect on blood cholesterol.²

 
 

Monounsaturated fats3	Polyunsaturated fats3 (Omega-3 and Omega-6)	Saturated fats4	Trans fats4	*Cholesterol6
Avocados Almonds, cashews & peanuts Cooking oils from plants and seeds (eg. canola, olive, peanut, sesame, sunflower)	Fish Sesame seed spread (tahini) Linseed and chia seeds Canola, sunflower, soybean and safflower oil Pine nuts, walnuts and Brazil nuts	Processed foods such as biscuits, cakes, pastries and takeaway foods Fat on red meat and chicken Dairy products Palm and coconut oil	Deep-fried foods Baked foods like biscuits, cakes, pastries and buns Small amounts naturally occur in dairy products, beef, veal, lamb and mutton	Offal (liver, pâté, kidney) Prawns Eggs

*In terms of blood cholesterol levels, cholesterol in food is far less important than eating less unhealthy fats (saturated and trans fats) and more healthy fats (monounsaturated and polyunsaturated fats)

High blood cholesterol: Who is at risk?

High blood cholesterol is an important risk factor for heart disease. Therefore, it is highly recommended that you visit your doctor so that you can discuss ways to reduce the risk of developing high blood cholesterol (or to start treatment as early as possible if necessary).⁷

 
 
As mentioned earlier, eating a diet with high amounts of unhealthy fats (saturated and trans fats) is a risk factor for high blood cholesterol. Other lifestyle factors that are known to increase your chance of developing high blood cholesterol include:⁸

• Obesity: Having a body mass index (BMI) greater than 30
• Large waist circumference: If you are a male with a waist circumference of at least 102cm or a female with a waist circumference of at least 89 cm
• Lack of physical activity: exercise helps to boost your good cholesterol levels
• Smoking: cigarette smoking damages the walls of your blood vessels, increasing the build-up of fatty deposits
• Diabetes: High blood sugar can contribute to more ‘bad’ cholesterol and less ‘good’ cholesterol

High blood cholesterol: Prevention tips

So, what can you do to reduce your risk of developing high blood cholesterol (and at the same time, reduce your risk of developing heart disease and other lifestyle-related chronic diseases)?:⁹

 
 

If you have several risk factors or already have high blood cholesterol levels, your doctor might recommend starting ‘lipid-lowering’ medication (which can lower fat and cholesterol levels in your blood). As with all medications, the benefits and risks need to be carefully considered.

 
 

References

1. European Food Information Council (online). Facts on fats: Dietary fats and health [accessed 30 Jan 2019]. Available from: URL link
2. Australian Government Department of Health: Eat for Health (online). Food Essentials: Fat [accessed 30 Jan 2019]. Available from: URL link
3. Heart Foundation (online). Healthy fat choices [accessed 30 Jan 2019]. Available from: URL link
4. Heart Foundation (online). Saturated and trans fat [accessed 30 Jan 2019]. Available from: URL link
5. Commonwealth Scientific and Industrial Research Organisation (CSIRO) (online). Cholesterol facts [accessed 31 Jan 2019]. Available from: URL link
6. Heart Foundation (online). Cholesterol in food [accessed 31 Jan 2019]. Available from: URL link
7. Heart Foundation (online). Blood cholesterol [accessed 31 Jan 2019]. Available from: URL link
8. Mayo Clinic (online). High cholesterol [accessed 4 Feb 2019]. Available from: URL link
9. The Royal Australian College of General Practitioners. Guidelines for preventive activities in general practice. 9th edn, updated. East Melbourne, Vic: RACGP, 2018. Available from: URL link