High Cholesterol

Cholesterol is a fatty substance produced by the liver that is transported around the body by different proteins. Cholesterol is present in cell membranes and is also used to isolate nerve fibres. It is an important substance that is used to make hormones such as testosterone and oestrogen, as well as producing vitamin D. When cholesterol is combined with proteins, they are called lipoproteins.

When doctors refer to good and bad cholesterol, they are talking about the two main types of lipoproteins:

• Low-density lipoproteins (LDL) are known as bad cholesterol. They carry cholesterol from the liver to your cells.
• High-density lipoproteins (HDL) are known as good cholesterol. They carry cholesterol from your cells to the liver to be broken down.

If you have too much LDL in your blood, the fatty material can start to coat the walls of your arteries and cause problems. The risk is particularly high if you have a lot of LDL and a small amount of HDL.

This makes it more difficult for blood to flow through your arteries, causing problems in the body. It affects the heart and brain primarily, but it can also be fatal.

• When you have your cholesterol tested, it will be measured in millimols per litre of blood (mmol/l). Total cholesterol should be less than 5.5 mmol/l. LDL should be under 2 mmol/l and HDL should be above 1 mmol/l.

High cholesterol is an important health issue in Australia. Around 50% of Australian adults have cholesterol levels of greater than 5 mmol/l. Although cholesterol is important, you do not need to get any from the food that you eat. Your body can produce the necessary cholesterol by itself.

There are hardly ever immediate symptoms of high cholesterol, but it can have a long-term impact. High cholesterol is not an illness itself, so there aren't normally tell-tale signs.

Most people only realize that they have high cholesterol when it starts to cause health problems. In fact, high cholesterol is usually only detected once it has caused an emergency event such as a stroke or a heart attack. Emergency events only occur once high cholesterol has caused the formation of fatty deposits known as plaque in your arteries. Plaque is responsible for serious health complications.

If plaque builds up:

• In the coronary blood vessels of your heart, you may get coronary heart disease. This can cause angina and heart attacks. Coronary heart disease is the biggest killer in Australia.
• In the arteries of your brain, you could have a stroke if the artery gets blocked.
• In the artery of your arm, kidney, or leg, you may get peripheral vascular disease.

As a result certain groups of people should be tested regularly for high cholesterol.

You may be tested for high cholesterol if you:

• are overweight
• are obese
• have high blood pressure
• have a kidney condition
• have an underactive thyroid gland
• have an inflamed pancreas
• have been diagnosed with coronary heart disease
• have had a stroke
• are over 40 years old
• have a family history of high cholesterol
• have a family history of early cardiovascular disease

You should get checked out if you have any of the conditions mentioned above, or if you are worried that your diet and lifestyle may be contributing to high cholesterol. High cholesterol can cause atherosclerosis, heart attack, stroke, angina, blood clots, and coronary heart disease.

There are a number of causes of high cholesterol. Factors that can lead to high cholesterol include:

• Eating lots of food that is high in saturated fat, such as butter, fatty meat, dairy produce, coconut oils and creams
• Smoking
• Sedentary lifestyle
• High alcohol intake
• Kidney or liver disease
• Obesity
• Familial hypercholesterolaemia (FH), an inherited condition that causes exceptionally high cholesterol even with a healthy lifestyle

It can be difficult for doctors to diagnose high cholesterol because there are rarely any symptoms. However, there is a blood test that can be done to measure your cholesterol.

Some doctors recommend that you get your cholesterol checked at 20 years of age, and then every 4-6 years after that. Australian doctors say that you should have cholesterol and triglyceride tests every 5 years from the age of 45 onwards, or from 35 onwards if you are Aboriginal or a Torres Strait Islander.

Those at higher risk of high cholesterol should be tested more often, as should those with a family history of related problems.

At the same time your doctor may carry out a test for triglyceride levels. Triglycerides are a type of fat from food that is stored in the body to be burned as energy. They are transported around your body in your blood, and excess triglycerides can also lead to fatty plaques in your blood vessels.

Once your doctor has performed this test and the results have come back from the laboratory, they will compare the results with your body mass index (BMI) to see if you need to have treatment.

Some people may be given medication to help lower cholesterol, but most people will be expected to change their lifestyle instead. If you are at high risk of cardiovascular disease you may be prescribed medication known as statins.

These prescription treatments lower the amount of bad cholesterol in your blood, but they only work in conjunction with lifestyle changes. Statins are not a magic pill for high cholesterol, but they are very effective if you make the effort to change certain aspects of your life at the same time. The chance of experiencing side effects is very low.

In addition to prescription medication, you can also use over-the-counter (OTC) treatments to reduce cholesterol. Some doctors recommend aspirin to prevent blood clots, and niacin can reduce bad cholesterol while increasing the amount of good cholesterol. Another medication called ezetimibe can also be taken as an alternative to statins, or at the same time as the prescription medication.

You can take action to reduce your cholesterol in various ways. The most important factors are eating a healthy diet, getting regular exercise and quitting smoking.

• Eat fruit, vegetables, and wholegrain rather than foods that are high in saturated or trans fats.
• Replace saturated fats with monounsaturated and polyunsaturated fats from olive, sunflower or rapeseed oils and spreads.
• Make sure you are eating lots of soluble fibre, which is found in oats, lentils, pulses, beans, fruits, and vegetables. Soluble fibre can reduce cholesterol.
• You can also try eating foods enriched with plant sterols and stanols, substances that are said to help reduce the level of bad cholesterol in your blood by 10-15% if you eat 2 grams per day. Sterols and stanols can be found added to margarine, spreads, soft cheeses and yoghurts.
• Some people say that you should eliminate dairy foods from your diet, but this is not the case. You should maintain a balanced diet that includes dairy foods.
• Eggs are a popular food to avoid among those that are trying to lower their cholesterol. This is because they contain cholesterol. However, it is not necessary to cut eggs completely from your diet.
• Seafood, such as prawns, also contains cholesterol, but it can also remain part of a healthy balanced diet.

Physical activity can boost levels of good cholesterol, and helps to maintain a healthy heart:

• Try walking upstairs instead of taking the lift, or getting off the bus a stop early.
• Aim for at least 30 minutes of brisk walking per day.

In fact, the Australian Physical Activity and Sedentary Behaviour Guidelines say that most adults should get 2.5-5 hours moderate-intensity activity per week. Those over the age of 65 should get at least 3.5 hours activity per week. The more active you are, the better it is for your cardiovascular system.

You should stop smoking if you are worried about cholesterol, as smoking enables LDL cholesterol to damage artery cells. Stopping smoking will also boost the health of your cardiovascular system.

If you are diabetic it is important that you manage your condition properly. High blood sugar has been linked to atherosclerosis, heart attacks and strokes, which are also a risk with high cholesterol.