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Cholesterol and Health
Cholesterol is needed for health and is made in the liver from fats eaten in the diet. However, the cholesterol level in the blood can become too high. A high cholesterol level is a 'risk factor' for developing atheroma.
What is atheroma?
Atheroma is fatty lumps or 'plaques' on the inside lining of the arteries (blood vessels). It can be likened to scale forming in water pipes when they become 'furred up'. It takes years for tiny atheroma lumps to become bigger and thicker inside the arteries. Some arteries can eventually become narrowed by atheroma and restrict blood flow. This is sometimes called 'hardening of the arteries'. In the heart, this can cause angina. Sometimes a thrombosis (blood clot) forms over a plaque of atheroma which can cause heart attacks, strokes or other serious disorders.
What are risk factors?
Everybody has a chance of developing atheroma. However, the extent and thickness of the atheroma is made worse by certain risk factors.
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Reversible (treatable) risk factors are - smoking, hypertension (high blood pressure), high cholesterol level, obesity and lack of exercise. |
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Fixed risk factors are - a family history of early atheroma (for example, parents, brothers or sisters who had a heart attack or stroke early in their life) and being male. Having diabetes is a fixed risk factor but good control of diabetes is better for the heart than poor control. |
Therefore, if the cholesterol level is high, there may be a higher than average chance or risk of developing angina, heart attacks, other heart disorders, strokes and other artery conditions. The increased risk depends on how high the level of cholesterol is and whether other risk factors are present. Risk factors add up so to have two, three or more risk factors is more risky than just one. Other reversible risk factors, mentioned above, are just as important to deal with as a high cholesterol level.
What causes high cholesterol?
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For many people, too much fat in the diet is the cause of a high cholesterol level. |
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In some people a high cholesterol level is due to another condition. For example, an underactive thyroid gland, obesity, alcohol excess and some rare kidney and liver disorders Also, some medicines used for other conditions sometimes increase the cholesterol level. |
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In a small number of people there is a genetic tendency to have high levels of cholesterol. This tends to run in families. One example is called familial hypercholesterolaemia. |
How high is high?
A blood cholesterol level of less than 5.0 mmol/l is best but levels slightly higher than this may be acceptable (but perhaps could be lower to be ideal). However, one study showed that about 1 in 4 adults in the UK have a cholesterol level greater than 6.5 mmol/l. So it is very common to have a level higher than is recommended! As a rule, the higher the level the greater the risk. This has to be put into perspective. The presence of other risk factors makes the risk much higher. So, for example, for a man who smokes and has a strong family history of heart disease, a level of 6.2 mmol/l is more of a concern than a woman with no other risk factors with a similar level.
A further factor is that total cholesterol is made up of different types of cholesterol. Cholesterol associated with a blood fat called high density lipoprotein (HDL) is 'good' and a high level of this type of cholesterol makes the risk less. Whether a given cholesterol level gives a high, medium or low risk of future ill health depends on the presence of other risk factors and the level of HDL type cholesterol. The practice nurse or GP will interpret the cholesterol level for an individual bearing in mind age, sex, other risk factors, other medical conditions and type of cholesterol.
What can be done if cholesterol is high?
Sometimes a non-diet cause is found for the high cholesterol, for example, an underactive thyroid or high alcohol intake. If the underlying condition is treated, the cholesterol level may reduce without any further treatment. However, for the majority of people, a high cholesterol level will often reflect weight, diet and lifestyle. The following may reduce the level.
Weight - if overweight, losing weight often reduces a high
cholesterol level. Even if an ideal
weight is not achieved, losing part of excess weight will help.
Diet
- if you are not overweight, the total calories need not change
but the make up of the
diet may need to change. There are various diet sheets available listing which
foods are
good and which are bad. A practice nurse or dietician may advise how to alter
the diet.
Briefly, a diet to lower cholesterol includes a) reducing the total fat content
of the diet and
increasing the relative amounts of protein, carbohydrates and fibre b) changing
the type of
fat in the diet by increasing the proportion of foods with mono and
polyunsaturated fatty
acids and reducing the proportion of foods with saturated fatty acids. In
practice this means
eating:
LESS fatty meats, fatty cheeses, full cream milk, fried food, lard, etc and
MORE lean meat, poultry, fish, skimmed or semi-skimmed milk, grilled food,
vegetables,
fruit, cereals, rice, pasta, nuts, wholegrain bread etc. And if you have to fry
choose a vegetable oil such as sunflower oil, or rapeseed oil or olive oil.
Alcohol - excess alcohol can be a factor and reducing this, if relevant, may help.
Medication - many people reduce a high cholesterol level with diet
and lifestyle changes.
Medication may be advised for some people if the level remains too high despite
a trial of
dietary changes. However, the advice to start medication is not based solely on
the level of
cholesterol. It takes into account other risk factors and illnesses which, in
combination with
a raised cholesterol level, may increase the risk of future ill health to a
level where treatment
may be beneficial.
Further help and information
Family Heart Association, 7 North Road, Maidenhead, Berkshire, SL6 1PE
Tel: 01628 628 638
Web:
www.familyheart.org
Provides information on heart disease and its management by diet, lifestyle and
medication.
British Heart Foundation, 14 Fitzhardinge
Street, London W1H 4DH
Heartline: 0870 600 6566
Web:
www.bhf.org.uk