High Blood Cholesterol

In the 1998 National Health Survey about one quarter of Singaporeans were found to have high cholesterol levels, a steep increase from the 19% in the 1992 survey. If their condition is allowed to persist, these people would be at risk from suffering serious consequences such as heart disease, stroke and high blood pressure.

What is Cholesterol ?

It circulates in the blood as a fat-like substance which is required by the body to develop cell walls and help in body functions like hormone production. The two sources of cholesterol are the body itself, where it is made in the liver, and the food we eat, particularly eggs, milk, red meat, shellfish, poultry skin and fats such as butter, lard and cooking oil.

Good and Bad Cholesterol

Cholesterol cannot dissolve in the blood unless it is combined with a lipoprotein. The cholesterol which is combined with low density lipoprotein(LDL) is called LDL cholesterol(LDLC) and the cholesterol combined with high density lipoprotein(HDL) is called HDL cholesterol(HDLC).

LDLC is called the "bad" cholesterol because high levels are associated with increased risk of heart disease. LDLC gets deposited in the artery walls and cause thickening and narrowing, leading to arteriosclerosis. When this occurs in the arteries leading into the heart, there could be insufficient blood supply to the heart when it needs more blood to carry more oxygen required for it to pump faster during exertion or heavy exercise. This results in ischaemia (chest pain) and if a blood clot forms in the artery, destruction of some heart muscle can occur (heart attack). A blood clot in the brain can cause a stroke.

HDLC is the "good" cholesterol because HDLC particles can help prevent arteriosclerosis by removing LDLC from artery walls and getting rid of them via the liver. Therefore low HDLC and high LDLC are risk factors for arteriosclerosis.

Causes

The common causes of high cholesterol are :

• hereditary, where the liver tends to overproduce cholesterol.
• eating too much cholesterol-rich food.
• eating insufficient fibre which is needed for excretion of cholesterol.
• over-sedentary lifestyle - exercise is useful in improving the balance between LDLC and HDLC.

Symptoms

Usually none, until arteriosclerosis develops. Obesity is usually a warning sign but even underweight people can have high cholesterol levels if their body is overproducing cholesterol.

Treatment

As a first step, consider the following :

1) Modifying diet and eating habits for these main food categories :

• Meat/fish : eat lean meat, trim off fat and poultry skin. Avoid organ meat, shellfish, bacon, sausages, hotdogs and egg yolk.
• Dairy products : go for fat-free or low fat varieties, take less full cream milk, hard cheeses and sour cream.
• Fats,oils : use more corn, olive, soyabean, canola or groundnut oil for cooking. Be wary of saturated fats present in butter, lard, ghee and coconut/palm oils. Avoid deepfrying.
• Breads,cereals : wholemeal bread and pasta are healthier choices than plain bread and store-bought pre-cooked pancakes/waffles/cereals which are likely to be made with palm oil.
• Fruits and vegetables : fresh, frozen or dried are preferable to canned or processed with addition of sugar, cream or sauce.
• Snacks : low-fat ice cream, yoghurt, fruit juices and homemade cakes/cookies made with unsaturated oil are better than full-fat ice cream/yoghurt, fried chips/nuts/pies where palm oil is often used to enhance the taste/fragrance of the fried food.

2) Increasing aerobic exercise. Usually swimming or brisk walking for 30 minutes three times a week is helpful for all age groups but medical advice should be sought. This activity is especially useful in increasing HDLC.

3) Reducing body weight, preferably with exercise and diet.

4) stop smoking, if applicable.

Proper diet and exercise can reduce total cholesterol by as much as 20% and medication should be regarded only as a last resort.

Drugs available include :

• Statins, eg. fluvastatin and lovastatin are widely used for improving the balance between LDLC and HDLC.
• Fibrates such as fenofibrate and gemfibrozil are used for increasing HDLC levels.
• Nicotinic Acid (Niacin) is sometimes used for increasing HDLC but requires high doses which cause side-effects like flushing, itchy skin and gastric upsets.
• Lecithin, which acts as a fat emulsifier to reduce the deposit of cholesterol in the blood vessels.
• Resins, eg. cholestyramine can lower total cholesterol by reducing intestinal reabsorption of bile acids.
• Red yeast rice and other products like carnitine and methionine which may stimulate liver production of lecithin.

You can help your doctor to evaluate your condition accurately, make a correct diagnosis and decide on an appropriate treatment strategy. Tell him about the various characteristics, location and duration of likely symptoms and what other conditions you have, including any medicines/herbs you are taking.

Do not be afraid to ask your doctor questions which will help you to understand your own condition better, eg.:

• what is my cholesterol profile and LDLC:HDLC ratio?
• what can I do to improve the profile ?
• what types of exercise and intensity are suitable for me ?
• should I take any medicatiion ?
• will the medication interfere with other drugs I am currently taking ?
• what side effects are likely ?
• what are the target levels for my cholesterol profile ?
• how often should I check my cholesterol profile ?