Cholesterol - What's My Level

Introduction

We couldn't live without cholesterol. It's in every cell in our body, helps us digest fats, keeps our nerves healthy and helps us make vital hormones.  Yet for all its life-supporting properties, cholesterol can be a threat. High levels of cholesterol in our blood increase our risk of heart and circulatory diseases.

Have you got your cholesterol under control?

What is cholesterol?

Cholesterol is a type of fat, a soft, waxy substance (lipid), most of which is made in the liver, from the fat that we eat. It's also found in foods such as eggs, meat and dairy products and especially in saturated fats.

Your body produces all the cholesterol it needs. So eating a diet that is high in cholesterol increases the amount in your blood, and can lead to health problems.

Cholesterol is transported around our bodies in the blood stream, attached to proteins. Together they're known as lipoproteins.

There are two main types of lipoproteins:

• Low-density lipoproteins (LDL) are often also known as 'bad' cholesterol. LDL transports cholesterol from the liver to cells. If there is too much LDL, it can result in a build-up of deposits in the blood vessels, narrowing them and reducing the space through which blood can flow.

• High-density lipoproteins (HDL) are often also known as 'good' cholesterol. These are the ones you want more of, as they remove the LDL from your blood stream and take it back to your liver. Once there, the LDL leaves your body as a waste product (through your bowels), or is broken down so it is no longer harmful.

High levels of HDL can give some protection against heart disease.

Other substances that are linked to cholesterol are triglycerides. These are also a type of fat found in the blood. They are made in your liver, and in meat, cooking oils and dairy foods such as cream and cheese.

When you take in more calories than you actually need (alcohol or sugar, for example) your liver produces triglycerides, which are carried in the bloodstream to your body tissues and stored as fat.

How high is too high?

Cholesterol levels vary from person to person. The important fact to remember is that the higher your cholesterol levels are, the more at risk you are of developing heart conditions.

Current guidelines say that our total cholesterol levels should be less than 5 mmol/l (millimols per litre), and that our LDL cholesterol levels should be less than 3 mmol/l. However, figures from Heart UK, the cholesterol charity, show that the average total cholesterol level in the UK is 5.7.

If you have been told by your GP that you are at higher risk of a heart attack or other heart conditions, your total cholesterol level should be less than 4 mmol/l and your LDL cholesterol should be less than 2 mmol/l. These levels were recommended by the Joint British Societies, which include the British Cardiovascular Society, British Hypertension Society, Diabetes UK, HEART UK, Primary Care Cardiovascular Society and the Stroke Association.

The balance of LDL and HDL is an important factor when deciding whether your levels are too high. The greatest risk comes from having low levels of HDL and high levels of LDL and triglycerides. 

What causes high cholesterol?

The way we live can put us at risk of high cholesterol, but the positive part of this is that in many cases you can take steps to reduce your risk.

Diet is an important factor in avoiding high cholesterol levels. If you eat foods that contain high levels of saturated fat, you'll be increasing your risk, as your liver turns saturated fat into cholesterol.

Processed meat such as sausages and pies, red meat, baked food such as biscuits and cakes, hard cheese, butter, lard, and cream all contain saturated fat.

Other risk factors that you can control include:

• Smoking
• Being overweight or obese - you're more likely to have a lower level of HDL and a higher level of LDL
• Low levels of physical activity or exercise - this can decrease your HDL level and increase your LDL level
• Drinking too much. NHS guidelines recommend three to four units a day for men and two to three units a day for women

There are also medical conditions that can increase your blood cholesterol level.

Conditions that push up cholesterol levels:

• Diabetes
• High blood pressure (hypertension)
• High triglyceride blood levels
• Some kidney and liver diseases
• Under-active thyroid gland

There are some risk factors you may not be able to change:

• You have a family history of heart disease or stroke under 55 in a close male relative or under 65 in a close female relative
• You have familial hypercholesterolaemia, an inherited condition which means that those people who are affected have high cholesterol
• You are a man over 45
• You are a woman over 55
• You are a woman who had an early menopause
• You are a member of an ethnic group that has low levels of HDL, particularly the Bangladeshi and Pakistani communities

What are the symptoms?

High cholesterol doesn't usually produce any symptoms on its own, however, you may have symptoms from a medical condition caused by high levels of cholesterol.

Symptoms to watch out for:

• Leg pain when exercising due to build up of cholesterol deposits in the arteries (atherosclerosis)
• Angina (chest pain) again due to atherosclerosis
• Yellow patches on the skin (xanthomas) formed by cholesterol. Often associated with familial hypercholesterolaemia

Why does it matter?

Having high cholesterol means that your arteries are more likely to narrow as cholesterol in the form of plaques build up on the inside surface of the arteries.

The arteries can become increasingly furred up with deposits (plaques), allowing less space for blood to pass through. It's known as atheroma or atherosclerosis (or "hardening of the arteries"), and can restrict blood flow through your arteries.

When your coronary (heart) arteries are narrowed by plaque it can cause angina.

Blood clots are more likely to develop when you have atherosclerosis and they can block the flow of blood. If this happens and stops blood flow to your heart, it can cause a heart attack. If a clot blocks blood flow to your brain, it can cause a stroke.

Who should have a cholesterol blood test?

Current guidelines in the UK recommend that anyone who is over 40, has a family history of heart disease at a young age, or an inherited condition that affects their cholesterol levels should have their cardiovascular health risk assessed.

The cholesterol blood test is usually carried out at your GP's surgery. You may be asked not to eat for 12 hours before the test, so your results aren't affected by any food you've eaten; most GPs do the test in the morning.

Your GP will also ask whether you smoke, whether there's a history of cardiovascular disease in the family and will check your blood pressure and your weight. This will all help to assess whether you have a high, moderate or low risk of developing cardiovascular disease.

What's the treatment for high cholesterol?

Your GP will recommend the most suitable treatment for you, depending on the results of your assessment. If you do have high cholesterol, your GP will probably start by looking at your diet. If you have a high risk of heart disease, your GP will combine lifestyle and diet changes with drug treatment with a statin drug, for example.

Move over to a healthy diet

One of the first steps you can take to improve your cholesterol levels is to change to a low fat diet. Cut back on the total amount of fat in your diet and reduce the amount of saturated fats you eat.

Replace saturated fats with moderate amounts of:

• Monounsaturated fats, found in olive oil, walnut oil, rapeseed oil, avocado and some margarines and spreads
• Polyunsaturated fats, found in cornflower oil, sunflower oil, fish oil and some margarines and spreads
• Omega-3 fats, which can help prevent blood clotting and help lower triglyceride levels. These are found in oily fish such as herring, kippers, pilchards, mackerel, sardines, salmon and fresh tuna

Eating a high-fibre diet may also help lower how much cholesterol is absorbed into your blood stream. Soluble fibre is an especially good choice. It's found in oats, beans, peas, lentils, chickpeas, fruit and vegetables.

Eating at least five different portions of fruit and vegetables a day will help reduce your risk of heart disease.

You should also have a good balance of carbohydrates, from wholegrain bread, rice, pasta and potatoes, and protein from lean meat, such as chicken and oily fish.

Research has found that walnuts, which contain polyunsaturated fatty acids, can reduce blood cholesterol and keep blood vessels healthy.

Exercise

Regular exercise is vital to keep your heart, and the rest of you, healthy. Yet far too few of us achieve the recommended amount - 30 minutes of moderate intensity exercise on five days of the week.

Health data from the British Heart Foundation is very persuasive. Inactive people have twice the risk of developing coronary heart disease as active people.

Exercise makes your heart stronger and more efficient, so it pumps more blood every time it beats. The more exercise you do, the stronger your heart becomes.

Regular exercise slows down the rate at which the arteries to the heart and brain narrow as we age. And physical activity increases the level of 'good' HDL, giving you more protection against 'bad' LDL.

If you don't take regular exercise, start slowly and build up gradually. Walking is ideal to start with and will help build up your endurance and strength.

Cycling, dancing, gardening, swimming, housework, Pilates, climbing stairs, and yoga are all good ways of exercising.

Choose something you enjoy, do it with a friend and keep it up. Regular moderate exercise is better for you than occasional bursts of activity.

Medication

There are a number of different types of medication that can bring down your cholesterol levels. Your GP will talk to you about whether you need to take cholesterol-lowering drugs, and which type is best for you.

• Statins are often prescribed to bring down levels of LDL and increase levels of HDL). They work by blocking the liver from making cholesterol.  Statins can reduce LDL cholesterol levels by between 15 to 20 per cent per cent. Statins can cause side effects, including constipation, diarrhoea, headaches and muscle pain. Low-dose statins are available at pharmacies over-the-counter (OTC) without a prescription
• Aspirin can prevent blood clots forming, so reducing the risk of heart attacks and stroke
• Fibrates are usually prescribed to reduce high levels of triglycerides, but they also reduce cholesterol. They are most often prescribed for people with an inherited lipid disorder, or who have high levels of triglycerides and cholesterol
• Bile acid binding drugs, also known as resins, help your body to use more LDL, so reducing the amount in your blood stream

Your GP may recommend using a combination of approaches, such as taking statins and making changes to your lifestyle.

Even if your risk is moderate, and you don't need to take action, you don't need to take a test to know that eating more healthily and taking more exercise is a smart move for your heart and your health.

Clickthrough information and support links:

British Heart Foundation

Heart UK