Cholesterol Explained

The inside story of cholesterol: what it is, where it comes from, what it's good for, what it's bad for and what your number actually means. It's all here in plain English.

Introduction

Most people nowadays have heard of cholesterol, and those with coronary heart disease will probably be better acquainted than most with the terms cholesterol and lipids and what they mean in respect of their health. This section aims to 'fill in the gaps' to help you take control of your cholesterol.

Coronary heart disease remains the biggest killer in the UK, killing over 117,000 people each year. Experts suggest that raised cholesterol is the most common risk factor, being a major factor in nearly half (46%) of all deaths from heart disease.

With 70% of the UK population aged over 45 years having raised cholesterol, most of us would therefore benefit from simple lifestyle adjustments to lower our cholesterol.

'At Risk' groups include those with existing heart conditions and those with Diabetes.

What is cholesterol?

Cholesterol and triglycerides are the two main lipids, or fats, in the blood. They are made by the body (mainly in the liver) and are also present in the food we eat. All of our body's cells contain cholesterol and although harmful to health in excessive levels, some cholesterol is vital for healthy cells. Cholesterol's three main beneficial functions are listed below:

Cholesterol is actually present in foods such as meat, dairy products and eggs. Although the amount of cholesterol manufactured by the body varies depending on dietary cholesterol intake, the biggest influence on blood cholesterol is dietary saturated fat intake. An excessive amount of saturated fat in the diet leads to increased blood cholesterol levels. The Guideline Daily Amount for Saturated Fat is 20g a day. Saturated fat is found in high quantities in foods such as fatty cuts of meat, pastries, hard cheese and butter.

If the body accumulates too much cholesterol, it forms deposits in the blood vessel walls, damaging and narrowing the arteries and impairing blood flow to the heart and other vital organs.

These deposits are known as "atheroma plaques", which, when combined with hardening of the arteries, leads to the condition called atherosclerosis.

What level should my cholesterol be?

Experts recommend that we should all aim for a total cholesterol level below 5mmol/l (millimoles per litre) and LDL-cholesterol below 3mmol/l. However, those with established coronary heart disease, diabetes or a ten-year coronary heart disease risk of 20% or more should aim for a total cholesterol of below 4mmol/l and LDL-cholesterol of below 2mmol/l. Fasting triglyceride levels should be below 1.7mmol/l. Cholesterol levels should be checked every five years, however those at risk of heart disease should have their cholesterol levels checked every one or two years.

Heart UK estimates that currently the average cholesterol level in the UK is around 5.7mmol/l. Even modest reductions in cholesterol, combined with other healthy behaviours such as not smoking, weight loss, exercise and consuming a balanced diet, demonstrate a beneficial impact on the rates of heart and circulatory disease. For every 1% fall in cholesterol level, the risk of heart disease falls by 2%.

How can I reduce my level of cholesterol and risk of coronary heart disease?

Through diet modifications

A few simple steps to help follow a balanced diet can help towards achieving a more appropriate blood cholesterol level which in turn may help to reduce your risk of developing heart disease.

Eating for a healthy heart

Fat facts

A diet high in saturated fat is associated with high blood cholesterol levels and obesity, and can also contribute to the development of type 2 diabetes. Kellogg's Optivita range of cereals are low in Saturated Fat. Other tips include choosing low-fat cheese and yoghurts. If you have to use oil, go for one that's packed with monounsaturates such as olive oil or grapeseed oil. Use skimmed, semi-skimmed milk or soy milk on your breakfast cereal. Aim to eat fewer fatty and fried foods like cream, butter, fatty cuts of meat, some cakes, biscuits, pastries, take away foods which can all be high in saturated fat – keep these as occasional treats. Omega-3 fatty acids reduce the levels of fats in the blood and help prevent irregular heart rhythms and the formation of blood clots. The richest source of omega-3 fatty acids is oily fish and the Food Standards Agency recommend that eating 2 to 4 portions a week can provide the recommended amount to help prevent heart disease in those at higher risk. Swap canned tuna for grilled, fresh tuna, lunch on sardines with toast or serve salmon for dinner. Tinned sardines and pilchards are economical sources of fish. Reduce your salt intake. Adults should aim to consume less than 6g of salt per day, the guideline daily amount (GDA). Kellogg's Optivita is a no added salt cereal containing only a trace of salt per serving.

Other lifestyle modifications to reduce heart disease risk

Diabetes is an independent risk factor for coronary heart disease, and a cluster of abnormalities, collectively known as the "metabolic syndrome", often precedes the onset of type 2 diabetes. Metabolic syndrome is characterised by central abdominal obesity i.e. having a higher than healthy waist line, raised blood triglycerides and blood pressure, low HDL-cholesterol and unhealthy fasting glucose levels.

How do I test my cholesterol level?

Cholesterol testing, along with risk assessment and advice, is now available from pharmacists and all GP surgeries using a finger-prick sample of blood. It is recommended that adults from 40 years onwards should have a blood test at their GP surgery for Total Cholesterol and LDL and HDL cholesterol.

Risk Factors

Those with the following risk factors should see their doctor for a fasting lipid profile (total cholesterol, HDL and LDL-cholesterol and triglycerides, following a 12-hour fast):

Waist Circumference

Measuring waist circumference, to get an indication of central obesity, is thought to be a better indicator of overall health risk than measuring just body weight. Maintaining a healthy body shape is essential as high waist circumference has been shown to increase the risk of coronary heart disease. Central obesity is linked to the development of several risk factors such as abnormal cholesterol levels, insulin resistance, type 2 diabetes, metabolic syndrome, high blood pressure and likelihood of thrombosis which may lead to heart disease.

A handy rule of thumb is that your waist circumference should be less than half your height. This is why the Ashwell® Shape Chart can be used by all men and women to see the health risk associated with their body shape.

When lifestyle changes are not enough

or those with inherited lipid disorders such as familial hypercholesterolaemia (FH or inherited high cholesterol), pre-existing coronary heart disease or diabetes, lipid-lowering agents may be needed in addition to diet and lifestyle measures. The following classes of agents are prescribed for treating raised cholesterol and triglycerides:

Statins, which slow down the production of cholesterol in the liver and are very effective in reducing LDL-cholesterol in particular.

Fibrates, which reduce triglycerides and cholesterol.

Resins, which are relatively safe for children because they are not absorbed by the body.

Selective cholesterol absorption inhibitors, which block the absorption of both dietary and biliary cholesterol in the small intestine.

Nicotinic acid, which increases HDL-cholesterol.

Omega-3 fish oils, which reduce triglyceride levels.

The simple facts

Although some progress has been made towards reducing the number of heart attacks happening in the UK, they remain the UK's biggest killer – in fact we are eight and a half times more likely to die from a heart attack than breast cancer and six and a half times more likely to die from a heart attack than colon cancer.

It's never too soon to begin reducing your of heart disease and lowering your cholesterol level need not be difficult. Being aware of cholesterol level and making simple dietary and lifestyle changes are important first steps to taking control of your heart health.