Cholesterol is a fatty substance produced naturally by the body and found in our blood. It has many good uses (it helps make hormones like oestrogen, testosterone and adrenaline), but can become a problem where there is too much of it in the blood.
There are two types of cholesterol - 'good' (HDL) cholesterol and 'bad' (LDL) cholesterol. LDL cholesterol is the type of cholesterol that clogs blood vessels and HDL is the type of cholesterol that helps unclog blood vessels. If you have a high level of cholesterol, you are at greater risk of having high blood pressure, heart disease, a stroke and other diseases. High blood cholesterol can be lowered with healthy eating and in some cases midication.
Just like cholesterol, all fat is not bad! It is beneficial to your health to have a certain level of fat. Fats in food are a mixture of polyunsaturated, monounsaturated, saturated and trans fats. These different types of fats have different effects on your cholesterol level.
- Polyunsaturated fats - help lower blood cholesterol if your meals are low in saturated fat. Some examples of foods that contain polyunsaturated fats are fish, plain nuts (e.g. walnuts, hazelnuts and brazil nuts) and polyunsaturated margarines and oils.
- Monounsaturated fats - can help lower blood cholesterol if your meals are low in saturated fat. Foods that include monounsaturated fats include avocado, plain nuts (e.g. peanuts, cashews and almonds) and monounsaturated margarine and oils.
- Saturated fats - raise blood cholesterol. Foods that are high in saturated fats include many take-away meals, potato chips, commercial cakes, biscuits and pastries, butter and dairy products (full fat milk, cream, cheese, etc)
- Trans fats - raise total and LDL (bad) blood cholesterol and also reduce the HDL (good) component of blood cholesterol. Foods high in trans fats include those which use hydrogenated or partially hydrogenated vegetable fats such as baked products like pies, pastries, cakes, biscuits and buns.
High Cholesterol doesn't produce any symptoms and many people first learn they have high cholesterol only when they have a heart attack or a stroke.
Cholesterol levels in the blood depend on both dietary factors and the amount of cholesterol manufactured by the body. Approximately 75% of cholesterol is produced in the body and 25% is introduced via the diet. As we age, cholesterol levels generally rise as the body increases production. Genetic factors also have an impact.
There are several different types, which can be taken alone or in combination.
- Statins - these drugs block an enzyme used in the production of cholesterol. They also accelerate turnover of cholesterol by the liver. They can drop blood LDL levels by anywhere between 20 and 50 per cent, and increase HDL by 5 to 15 per cent.
- Cholestyramine and colestipol. These are older medications, also known as bile-acid-binding resins. They bind to bile acids in the intestine, preventing them from being absorbed into the body. The liver needs bile acids to make cholesterol – so less bile acids means less cholesterol.
- Gemfibrozil and fenofibrate. These drugs are used when the others don't work, or when levels of triglycerides (another common type of fats) are high – though they also increase the amount of HDL in the blood. Fenofibrate also lowers total cholesterol.
- Nicotinic acid can lower LDL (bad) cholesterol and triglycerides, and increase HDL cholesterol.
- Ezetimibe (brand name Ezetrol) is a new drug in a class called the cholesterol absorption inhibitors. It works by reducing the absorption of cholesterol from the intestine into the bloodstream. It reduces total cholesterol and LDL, and increases HDL cholesterol.
Lowering cholesterol by 10 per cent reduces the risk of heart attack by 20 per cent. The following steps will help lower cholesterol:
A diet low in saturated fats and high in monounsaturated and polyunsaturated fats. This means:
- low-fat or reduced-fat milk, yoghurt and other dairy products
- lean meat (meat trimmed of fat or labelled as 'heart smart')
- limited fatty meats, including sausages and salami, with leaner sandwich meats like turkey breast or cooked lean chicken instead
- fish (fresh or canned) at least twice a week
- butter and dairy blends replaced with polyunsaturated margarines
- plenty of fresh fruit, vegetables and wholegrain foods, nuts, legumes and seeds.
- plant sterols are a type of alcohol structurally similar to cholesterol and found in some margarines and fortified foods, in corn, rice, vegetable oils and nuts. They can also lower cholesterol.
Regular exercise (for example, at least 30 minutes of brisk walking daily). Exercise increases HDL levels and reduces LDL levels in the body.
The National Heart Foundation recommends that all adults over 45 years old have a regular blood cholesterol test every few years.
People younger than 45 who are at higher risk of coronary heart disease – for example, those who have a family history of hypercholesterolaemia, heart disease, high blood pressure and/or diabetes, should also have a regular cholesterol test.
A cholesterol test measures the total cholesterol in the blood.
Normal <5.5 MMO/L
For those people with risk factors inclding heart disease and diabetes <4.0 MMO/L