You’ve heard the term ‘cholesterol’. We have all seen foods and medications advertised on television boasting they will help to reduce your cholesterol levels. But what exactly is cholesterol and why does it need to be low?
Most of the cholesterol in our blood is produced by the body itself. It has an essential role in all cell membranes and how every cell in the body functions. However, people with high cholesterol concentrations in their blood have a higher risk of coronary heart disease than people who have lower levels. The risk is particularly high if you have a high concentration of LDL cholesterol and a low level of HDL cholesterol.
LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol transport fats, including cholesterol, around the body.
Blood cholesterol concentrations can be measured through a simple blood test. It will usually measure total cholesterol, LDL cholesterol and HDL cholesterol, and a ratio of total cholesterol to HDL cholesterol.
The main factors likely to increase total blood cholesterol levels (in particular LDL) include
Unfortunately, we can’t change our family history, but we can increase HDL and reduce LDL cholesterol concentrations by being more active, maintaining a healthy weight, eating a heart-healthy diet, reducing stress and not smoking. Some people may also require medication to help lower their cholesterol levels. Contact your doctor for advice on whether medication is necessary for you.
Making small changes to everyday eating is a good way to lower blood cholesterol levels. Base your diet around whole plant foods i.e., fruit, vegetables, whole grains such as oats, and legumes. They are high in soluble fibre, which may help lower blood cholesterol. Also, focus on reducing foods high in saturated fats and swapping them with healthier fats (monounsaturated and polyunsaturated fat).
There is a lot of confusion around eggs and cholesterol but it’s important to note the difference between dietary cholesterol and blood/serum cholesterol.
Eggs are high in dietary cholesterol but relatively low in saturated fat. We know now that dietary cholesterol only slightly increases our blood cholesterol levels (and responses vary from person to person). If you are trying to reduce your cholesterol levels, eating less saturated fat and upping your intake of whole plant foods is more important than your egg intake. In saying that, those with type 2 diabetes or at an increased risk of heart disease are encouraged to eat no more than six eggs a week. To learn more about eggs, visit our ‘Eggs’ webpage.
Plant sterols (or phytosterols) are found naturally in very small quantities in a variety of plant foods such as grains, vegetables, fruit, legumes, nuts, and seeds. They actively lower cholesterol by partially blocking the absorption of LDL or “bad” cholesterol in the digestive system. The Australian New Zealand Food Code permits the addition of plant sterols to edible oil spreads, breakfast cereals, milk, and yoghurt.
In a systematic review by Food Standards Australia New Zealand (FSANZ) (2014) it was concluded that there is a ‘High’ degree of certainty that increased plant sterol intake reduces blood total and LDL cholesterol concentrations. Because of the strong evidence plant sterols are effective in lowering LDL cholesterol, FSANZ approved a health claim.
The Health Claim states that 2g of plant sterols daily lowers cholesterol within 4 weeks as part of a healthy diet low in saturated fat. This has been proven in over 40 clinical trials that cholesterol is lowered by up to 9% within 4 weeks. The New Zealand Nutrition Foundation endorses this claim. Note that foods with added plant sterols only ‘work’ if eaten frequently in the recommended amounts. These foods are can be expensive and your overall diet is more important.
FSANZ (2014) Systematic review of the evidence for a relationship between phytosterols and blood cholesterol. Report prepared by Food Standards Australia New Zealand, Canberra.
National Health and Medical Research Council (Australia) and Ministry of Health (New Zealand) (2017) Nutrient Reference Values for Australia and New Zealand: Summary.
Last updated: July 12, 2022
Last modified: July 13, 2022