Cholesterol is a type of fat that is found naturally in the body. It is important for the structure of our cell membranes and is essential for many metabolic processes. Our body also uses cholesterol for hormone production, and to help the body produce vitamin D.
Cholesterol in the body comes from two sources. The majority comes from the body’s natural production of from the liver, with the rest coming from the diet. Dietary sources of cholesterol only come from animal-based foods (meat, seafood, eggs, dairy etc.) not plant foods (fruit, vegetables, grains etc.)
About half of the cholesterol we eat (dietary cholesterol) is absorbed by the body, but it has a neutral effect on blood cholesterol levels. However overall diet can influence (either positively or negatively) blood cholesterol levels too. See Heart Health Steps section to learn more about a heart healthy diet.
There are two main types of cholesterol in our blood:
- Low density lipoprotein or LDL cholesterol (the ‘bad’ type); and
- High density lipoprotein or HDL cholesterol (the ‘good’ type)
If you have a blood test to check cholesterol it may also tell you the total amount of cholesterol, and triglycerides (another type of fat in the blood) too.
For the general population cholesterol targets are:
- Total Cholesterol: <5.5mmol/L
- LDL Cholesterol: <2mmol/L
- HDL cholesterol: >1mmol/L
- Triglycerides: <2mmol/L
Many things and risk factors can influence cholesterol levels and what they mean for individual health. For example, if you are considered at high risk of heart disease you may have lower targets set. Always discuss with your individual circumstances, risk profile and results interpretation with your GP.
Too much total cholesterol, especially too much LDL cholesterol is not good for our long-term heart health. Too much LDL cholesterol in the blood can cause fat build ups to start being found in the arteries (passages that carry blood from the heart to the rest of the body), which can eventually lead to narrowed or blocked arteries. When this occurs, it could lead to cardiovascular diseases, heart attack or stroke.
If you are concerned about your heart health, particularly as you get older from about the age of 45, it’s a good idea to get a cholesterol test regularly. Ask your GP and they will help you organise the simple cholesterol test and heart health check.
- https://www.csiro.au/en/research/health-medical/nutrition/cholesterol-facts
- Cohen. Balancing Cholesterol Synthesis and Absorption in the Gastrointestinal Tract. J Clin Lipidol. 2008 Apr;2(2):S1–S3. https://pmc.ncbi.nlm.nih.gov/articles/PMC2390860/#:~:text=Consequently%2C%20most%20cholesterol%20within%20the,%2C%20and%20average%20approximately%2050%25
- https://pmc.ncbi.nlm.nih.gov/articles/PMC2692399/#:~:text=The%20human%20diet%20provides%20%E2%88%BC,feces%20(10%2C%2039)
- https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/cholesterol#safe-blood-cholesterol-levels
- https://www.heartfoundation.org.au/your-heart/high-blood-cholesterol
