Published by Bupa's health information team, March 2009.
This factsheet is for people who have high cholesterol, or who would like information about it. Cholesterol is a type of fat (lipid) made by the body. It's essential for good health and is found in every cell in the body. However, having a high cholesterol level in the blood (hypercholesterolaemia) can increase the risk of heart disease and stroke.
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About two in three adults have a cholesterol level that is higher than recommended. Having high cholesterol affects your heart and blood vessels and increases your risk of developing cardiovascular disease (CVD). High cholesterol causes fatty deposits (known as plaques) to build up inside your blood vessels.
In time, the blood vessels supplying your heart may become so narrow that they can't deliver enough oxygen to the heart muscle, particularly when you're exerting yourself. This can cause you to feel chest pain (angina). If a fatty plaque breaks off, it may cause a blood clot which can block blood flow to your heart (heart attack) or brain (stroke).
Cholesterol is transported around your body attached to a protein in your blood. This combination of fat and protein is called a lipoprotein. There are different types of lipoprotein, depending on how much fat there is in relation to protein.
A small amount of cholesterol is transported as HDL, which is mostly protein and not much fat. The role of HDL is to transport excess cholesterol from the tissues (including the walls of arteries) to the liver for disposal. As HDL helps prevent cholesterol building up in your blood vessels, you have a decreased risk of heart disease if you have high levels of this type. HDL is considered to be the "good" type of cholesterol. Women tend to have higher HDL levels than men. HDL can be increased by physical exercise.
Most of your body's cholesterol (around 70 percent) is transported in this form. It consists mainly of fat, with not much protein. LDLs are chiefly involved in transporting cholesterol from the liver to the cells. High levels of LDL are associated with an increased risk of CVD as LDL causes cholesterol to be deposited in your blood vessels. LDL is considered to be the "bad" type of cholesterol.
These lipoproteins account for a small percentage of your body's cholesterol, but they are rich in triglycerides and transport them to the tissues.
Triglycerides are a different type of fat, mostly coming from fats in your food. Energy from food that is eaten and not used immediately is converted into triglycerides and transported to fat cells for storage. This provides you with an important source of stored energy.
Although most triglycerides are stored as fat, low levels are also found in your blood. A raised level of blood triglycerides together with high LDL can increase your risk of heart disease, particularly if you have diabetes.
Having a high TC level is a risk factor for future health problems. However, it's important to consider the relative amounts of HDL and LDL. This is often referred to as the TC:HDL ratio. You should aim for a high level of HDL and a low level of LDL (a low TC:HDL ratio).
A high cholesterol level may only be revealed if you develop symptoms of heart disease. Sometimes, yellow patches (known as xanthomas) may develop around your eyes or elsewhere on your skin - these are cholesterol deposits and indicate that you have high cholesterol levels in your blood.
There is an increased risk of heart disease, arterial disease and strokes. Your GP will discuss possible complications of high cholesterol with you.
There are several factors that may contribute to you having high blood cholesterol. These include:
Rarely, high cholesterol can be caused by a condition which may run in your family - this is called 'familial hypercholesterolaemia'. About one in 500 people have this condition.
Other conditions such as poorly controlled diabetes, certain kidney and liver diseases, and an underactive thyroid may also cause high cholesterol. Some medicines such as beta-blockers, steroids or thiazides (a type of diuretic) may also affect blood lipid levels.
Measuring cholesterol involves a blood test. Usually you will be asked not to eat for 12 hours before the test so that your food is completely digested and doesn't affect the test. A blood sample may be taken either by a needle and a syringe, or by a finger prick. You can have this test done at your GP surgery, at hospital, or as part of a health assessment examination.
Home-testing kits for cholesterol are also available but may not be very accurate. Speak to your pharmacist about your result if you choose to use a kit.
The amount of cholesterol in your blood is measured in units called millimoles per litre of blood, usually shortened to 'mmol/litre', 'mmol/L' or 'mM'. Current UK guidelines state that it's desirable to have a total cholesterol level under 5mmol/L, and an LDL level under 3mmol/L. However, you should aim to have a total cholesterol level under 4mmol/L and an LDL level under 2mmol/L if you're at high risk of heart disease.
You should have your cholesterol levels regularly checked by your GP if you have CVD (or are at high risk of CVD) or if you have a family history of high cholesterol.
There are two ways to help lower high cholesterol. The first is with lifestyle changes including changing your diet, managing your weight and increasing exercise. The second is to combine lifestyle changes with cholesterol-lowering medicines.
Healthy eating can reduce cholesterol. Your diet should be low in saturated fats in particular, and low in fat overall. Biscuits, cakes, pastries, red meat, hard cheese and butter all tend to be high in saturated fats, so cut down on these foods.
Some foods contain cholesterol. These foods include eggs, prawns and offal such as liver and kidneys. This type of cholesterol is known as dietary cholesterol and it has a much lower effect on blood cholesterol than saturated fat in your diet. You don't need to cut down on these foods unless your doctor has advised you to.
It's also important to eat plenty of fibre, especially soluble fibre, which is thought to lower cholesterol. Soluble fibre is found in fruits and vegetables, beans and oats. Aim to eat at least five portions of fruit and vegetables each day. Foods containing substances called plant sterols or stanols may help to lower cholesterol.
If you're overweight, an excess weight loss plan may help you to reduce your LDL levels and increase your HDL levels. Increasing your physical activity may enhance the cholesterol-lowering effects of diet.
As high cholesterol can increase your risk of heart disease, you should reduce any additional risk of developing heart disease, eg by stopping smoking.
Your GP may prescribe cholesterol-lowering medicines if you already have heart disease, or are at high risk of getting it because you have other risk factors. The aim of treatment is to reduce your total cholesterol levels by a quarter or to less than 4mmol/L.
The main group of medicines for lowering cholesterol are the statins. Available statins include atorvastatin (Lipitor), fluvastatin (Lescol), pravastatin (Lipostat), rosuvastatin (Crestor) and simvastatin (Zocor). They work by reducing the production of cholesterol in the liver. These medicines can have side-effects such as indigestion and muscle pains.
Other types of medicines to reduce cholesterol include fibrates, nicotinic acid and cholesterol-absorption inhibitors such as ezetimibe (Ezetrol), but these are generally less effective than statins or have more side-effects. Your GP can tell you more about these medicines and suggest the most suitable treatment for you.
You may be able to prevent the development of high cholesterol by maintaining a healthy weight, eating a healthy diet, stopping smoking, not drinking excessive amounts of alcohol and taking regular exercise. However, if your family has a history of high cholesterol, it may be difficult to prevent yourself from having it too.
Bupa Wellness offers a cholesterol check as part of every Bupa Health Assessment, or through a visit to one of our private GPs.
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
Publication date: March 2009
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