Family doctor

What is cholesterol?

A white waxy substance normally found in all healthy cell membranes and necessary for the production of a variety of hormones. Most of the cholesterol in our body is produced by the liver, and the level in the blood is affected by certain types of food we eat.

What causes high blood cholesterol?

• A diet too high in saturated fats found mostly in animal products e.g. meat, chicken, eggs, dairy
• A genetic tendency to high blood cholesterol (runs in families)
• Inefficient liver function due to a variety of reasons - stress, caffeine, lack of exercise, smoking, alcohol, overweight
• Hormonal problems e.g. under active thyroid gland

What problems can cholesterol cause?

Excessive amounts of cholesterol in the body may build up in the artery walls over time, narrowing and hardening them until the blood flow is reduced. This increases the risk of heart disease (angina and heart attacks), and stroke.

What are the different types of cholesterol?

There are two main types of cholesterol; one of which can protect against heart disease, the other can cause it. All cholesterol is carried in the blood by proteins - together they are called lipoproteins.

• High density lipoproteins (HDL) are termed 'good' because they remove cholesterol from artery walls. A higher level of HDL is actually protective against heart disease.
• Low density lipoproteins (LDL) are termed 'bad' because they deposit on the artery walls. It is very important to try lower the level of LDL to reduce the risk of heart problems.

Which foods contain cholesterol?

Most cholesterol in the body is made in the liver from saturated fat in the diet, thus the important thing is to reduce your saturated fat intake as much as possible.

Fatty meats and full-fat dairy products are particularly high in saturated fat.

Some foods e.g. prawns are high in cholesterol, but low in saturated fat. Cholesterol intake per se should not be excessive, but it plays a much lesser role than saturated fat in determining your blood cholesterol level.

Most plant foods such as fruits, vegetables and cereal grains contain no fat or cholesterol.

What foods should you avoid?

• Cream, butter, cheeses, ice-cream, milk
• Vegetable fats such as palm oil or vegetable shortenings, some margarines
• Takeaways and fried or roasted foods that have had fat or oils added to them
• Meat pies, pastry, croissants, cheese-coated bread
• Sausage, luncheon sausage, salami
• Cakes, biscuits, puddings
• Chocolate and snack bars high in fat
• Roasted, salted nuts, crisps, crackers
• Alcohol - reduce to two evenings per week or drink low alcohol versions of wine and beer
• Eggs - no more than three per week

Foods to enjoy

• High fibre foods help to produce HDL cholesterol. Include daily:
• Wholegrain breads, cereals, brown rice, wholegrain pasta
• Leave skins on vegetables and eat them e.g. potatoes, kumara, taro
• Use wholegrain rolled oats for porridge or muesli, or add oat bran to breakfast cereals
• Avoid sugar and white flour in cooking and baked goods

Fresh fruits and vegetables contain antioxidants and vitamin C which protect the artery walls. Include daily:

• Three servings of fruit - raw, cooked, or tinned without sugar
• Two to five servings of vegetables - either raw as salads or lightly cooked.
• Include both green and red/yellow/orange vegetables

Choose lean meats, skinned poultry, or fish to reduce LDL cholesterol

• Use lean meats, cut all visible fat off, buy low-fat mince
• Do not eat the skin on poultry
• Eat up to three fish meals a week. Fish helps to reduce LDL levels
• Do not roast or fry foods. Instead, grill, bake, boil, or steam

Take care with dairy foods

• Use low-fat yoghurts, cottage cheeses, ricotta, quark and reduced-fat yellow cheeses
• Keep milk intake down and low in fat
• Keep cheeses such as cheddar, fancy cheeses, and feta cheeses to a minimum
• Try soy milk for a change and use soy beans, tofu, and soy ice-cream
• Avoid ice-cream - use low fat and low sugar versions or fruit-based jellies and sorbets
• Coconut cream and milk are high in saturated fat which produces LDL cholesterol

Go vegetarian

• Eat dishes containing beans, lentils, chickpeas, soybeans, and tofu . these do not contain cholesterol and they are high in fibre
• Eat pastry-less quiches, and lasagne dishes made with ricotta, cottage, or quark cheeses

Use the good oils

• Use monounsaturated oils and margarines e.g. olive and canola, these raise HDL cholesterol levels
• Avoid using butter, a saturated fat, or only use small amounts of unsalted butter
• Polyunsaturated oils such as sunflower, safflower, corn, soy, and nut oils will lower LDL cholesterol, but may also reduce the level of HDL cholesterol
• Choose takeaway foods that have minimal frying such as stir-fried Asian dishes
• Choose low-fat mayonnaises, soups, sauces, and salad dressings

Further tips for lowering cholesterol

• Exercise daily for a minimum of half an hour
• Reduce stress where possible
• Drink less tea, coffee, chocolate drinks and colas
• Stop smoking (smoking reduces the good HDL cholesterol)
• Aim for a healthy body weight

More information can be obtained from the National Heart Foundation of New Zealand and your local registered dietician.