Cholesterol
What is cholesterol?
Cholesterol is a fatty substance that is carried around the body in blood by structures called lipoproteins. There are two main types of lipoproteins that carry cholesterol to and from cells – these are low density lipoproteins (LDL-C) and high density lipoproteins (HDL-C). Most cholesterol in the body is produced naturally, but it can also be found in foods.
What is the difference between LDL-C and HDL-C?
The lower the density of a lipoprotein, the more fat it contains. Therefore, we call LDL-C ‘bad cholesterol’ as it is the type of cholesterol that can lead to blockage of arteries. HDL-C is known as ‘good cholesterol’, because it has the opposite effect and helps to keep cholesterol from building up in arteries. Treatments for high cholesterol such as statins usually target LDL-C.
What else is measured?
Total cholesterol is a reading of both types of cholesterol in the blood.
Triglycerides are also a measure related to cholesterol. These are another form of fat in the blood that can also increase the risk of heart disease. High triglycerides are often associated with low HDL cholesterol, increasing the risk of heart disease even though the total cholesterol may appear normal.
How do I know if I have high cholesterol?
High cholesterol usually does not cause any symptoms. A blood test is the only way to know if your cholesterol is high. Your doctor may suggest a cholesterol test if you have a family history of high cholesterol, or if you have additional risk factors such as high blood pressure, smoking or you are overweight/obese.
There are some genetic conditions that can cause high cholesterol. If you have a family history of high cholesterol, please discuss this with your GP.
What are the problems with high cholesterol?
One of the main problems with high cholesterol is that it causes ‘hardening of the arteries’ and can cause a blockage, leading to either a heart attack or a stroke. Both of these conditions can have very poor long term outcomes and may result in death.
How can I reduce my cholesterol?
If you have been advised by your doctor that you have high cholesterol, there are a number of dietary measures you can take to reduce this. These include:
- Reducing saturated fats in your diet. Foods that have high quantities of saturated fats and are common in the Australian diet include dairy products, including butter, cheese and ice cream (27%), red meats, poultry and meat dishes (20%), biscuits, cakes and pastries.
o Try to swap full fat dairy foods for low fat options, choose lean meats and poultry and limit consumption of biscuits, cakes and pastries
o It is important to note that lowering of total fat without altering the proportions of fat ingested has little effect on serum cholesterol levels (RACGP …)
- Increasing plant sterols: the Heart Foundation recommends consuming 2-3grams of plant sterols per day from plant sterol enriched foods (consuming more than this amount will do no harm but will not give any additional benefits).
o In Australia, plant sterol enriched foods include:
Margarine spreads
Breakfast cereal
Low-fat yoghurt
Low-fat milk
o Australian regulations allow 0.8-1g of plant sterols per serving, so therefore 2-3 servings per day will achieve 2-3grams per day
Other lifestyle measures to reduce cholesterol include weight loss (in those who are overweight), increasing dietary fibre and increasing soy protein.
It is also important to include other components of a ‘Heart Healthy Diet’ such as including oily fish, wholegrains, fruit, vegetables and nuts, as well as lowering alcohol intake.
Your doctor may decide to commence you on a medication to lower your cholesterol if they are concerned about the level or your underlying risk of heart attack or stroke. The most common of these medications is a statin which works to lower the level of LDL cholesterol in the blood. If you have any questions about any medications you may be commencing, please speak to your doctor or call us on (08) 8340 2233
References
Stephens C, Cafasso J 2016, ‘Symptoms of High Cholesterol’, HealthLine, retrieved online 2/8/17, < http://www.healthline.com/health/high-cholesterol-symptoms#overview1 >
Heart Foundation (date unknown), ‘Blood Cholesterol’, Heart Foundation, retrieved online 2/8/17, < https://www.heartfoundation.org.au/your-heart/know-your-risks/blood-cholesterol >
Clifton P, Colquhoun D, Hewat C 2009, ‘Dietary intervention to lower serum cholesterol’, Royal Australian College of General Practitioners, retrieved online 2/8/17, < http://www.racgp.org.au/afp/2009/june/lower-serum-cholesterol/ >
Heart Foundation 2007, ‘Position statement: Phytosterol/stanol enriched foods’, Heart Foundation, retrieved online 2/8/17, < https://www.heartfoundation.org.au/images/uploads/publications/Stanols-QA.pdf >