What is Cholesterol?
Cholesterol forms part of the outer membrane that surrounds every cell. It is used to insulate nerve fibres (and so make nerve signals travel properly) and makes hormones, which carry chemical signals around the body. Without cholesterol, your body would not work – it is vital to ensure the body’s normal function. Too much cholesterol in the blood however, increases the risk of coronary heart disease and disease of the arteries.
Good Cholesterol? Bad Cholesterol?
Knowing your cholesterol level is not, on it’s own, enough to tell you your personal risk of heart disease. You also need to know about LIPOPROTEINS. These are special molecules that carry or transport cholesterol around the body.
There are three main types :
- LOW DENSITY LIPOPROTEINS (LDL) – often referred to as BAD CHOLESTEROL – this carries cholesterol from the liver to the cells and if supply exceeds demand, can cause a harmful build up of cholesterol.
- HIGH DENSITY LIPOPROTEINS (HDL) – GOOD CHOLESTEROL – this takes cholesterol away from the cells and back to the liver, where it is either broken down or excreted.
- TRIGLYCERIDES The greatest danger is when you have high levels of LDL (bad) and trigylcerides, and low levels of HDL (good)
What is a Healthy Cholesterol Level?
The average total cholesterol level in Ireland is 5.5 mmol/l for men and 5.6 mmol/l for women, which is above a normal level. So does that mean that most people in Ireland are at risk of heart disease? Do they need to take anti – cholesterol drugs?
In recent years, we have come to realise that it is the BALANCE of different types of lipoproteins, rather than the overall total cholesterol level that matters. This overall risk is determined by a number of factors, including age, gender, family history of heart disease, smoker, being overweight, having high blood pressure or diabetes.
The higher the risk of heart disease eg. a male smoker with high blood pressure and diabetes, the greater the need to get cholesterol levels down.
The Department of Health cholesterol guidelines, which is the policy doctors follow are:
- TOTAL CHOLESTEROL – less than 5.0 mmol/l
- LDL CHOLESTEROL (BAD CHOLESTEROL) – less than 3.0 mmol/l
- HDL CHOLESTEROL (GOOD CHOLESTEROL) – greater than 1.1 mmol/l
However experts involved in cardiovascular disease recommend different cholesterol limits for people who have, or are at risk of coronary heart disease :
- TOTAL CHOLESTEROL – less than 4.0 mmol/l
- LDL CHOLESTEROL (BAD CHOLESTEROL) – less than 2.0 mmol/l
These guidelines match the more stringent recommendations used in Europe.
IMPORTANT – To have your cardiovascular health risk assessed you should visit your GP – your GP knows your medical history and will be able to advice and/or recommend treatment, depending on your cholesterol levels and your overall risk factors.