Subject to several decades of bad press, we now know that cholesterol is not the one-dimensional dietary bad-guy it was once throught to be. While it is never healthy to have high blood cholesterol, our bodies do need cholesterol for vital functioning.
What , and how much?
Cholesterol is a white waxy substance produced mainly by our liver. It is also found in animal food products. Plant foods have no cholesterol.
It is a structural part of every body cell wall and is the building block for vitamin D, sex hormones, and bile acids, which help in the digestion of dietary fats: it is essential to life
The body makes sufficient cholesterol for its needs and does not rely on cholesterol in the diet. Dietary fats have a major influence on blood cholesterol levels – more so than dietary cholesterol.
A high blood cholesterol increases the risk of atherosclerosis – the thickening of arteries that can reduce or block blood flow to the heart muscle, brain, eyes, kidneys, sex organs and other body parts. This in turn increases the risk of heart attack, stroke, blindness, kidney failure, impotence and other blood circulatory problems.
Other risk factors which increase the risk of atherosclerosis include high blood pressure, tobacco smoking, obesity and diabetes (uncontrolled).
|Check Your Blood Cholesterol|
|Cholesterol Level(mmol/litre)||Risk of Heart Attack|
|6.5 and over||Very High|
|5.5 – 6.4||High|
|4.2 – 5.4||Average|
|Less than 4.2||Low Risk|
It is wise to know your cholesterol level, particularly if there is a family history of heart disease or stroke. If the blood test comes back with a high reading, see your doctor for advice.
All adults should have their cholesterol, HDL, and triglycerides tested at least every 5 years.
Dietary fats and blood cholesterol
The amount and type of dietary fat has the greatest influence on blood cholesterol levels.
Fats in food are a mixture of three basic types: saturated, monunsaturated, and polyunsaturated. Animal fats are mainly saturated while plant oils and fish oils are mainly mono- and polyunsaturated.
Saturated fats have subgroups known as long chain, medium chain, and short chain fats. Most of the long chain fats raise blood cholesterol; and increase the risk of blood clots and thrombosis leading to artery blockage. Long chain saturated fats are found mainly in full cream milk, cheese, butter, cream, fatty meats and sausages, and processed foods.
Monounsaturated fats tend to more selectively lower the unhealthy LDL-cholesterol and maintain the protective HDL- cholesterol in the bloodstream – but only if they replace saturated fats in the diet. Foods rich in monounsaturates include oils and margarine made from canola, olives and Sunola; peanuts, and avocados.
Polyunsaturated fats consist of two main classes. Omega-6 polyunsaturates tend to lower blood cholesterol. Rich sources include safflower, sunflower and corn oils.
Omega-3 polyunsaturated fats can lower blood cholesterol, and also confer extra benefits by lowering blood triglycerides, and reducing the risk of thrombosis, heart arrythmia, and artery spasm. Best practical omega-3 sources include canola oil and margarine, soybean oil and fish.
A balanced intake of the two omega classes is important for optimal health. Increasing slightly omega-3 intake by Australians would help to attain a better balance. Adequate vitamin E intake is also important.
You do need to remember that all fats are high in calories and need to be limited for weight control.
Trans fats act like saturated fats and raise blood cholesterol. They occur naturally in dairy products and in some meats. You can also find them in some margarines and deep-frying fats.
Intake of trans fats in Australia is relatively low and falling. Many margarines no longer contain trans fats (and the levels in commercial frying fats are being reduced). Although trans fats contribute to cholesterol levels, saturated fats are much more common in our diet and are the major problem.
Diet hints to lower blood cholesterol
1. Maintain a healthy weight – if you are overweight, lose weight with low-fat eating and daily exercise.
2. Reduce your saturated fat intake. Eat less dairy fat. Choose low-fat or fat-reduced varieties of milk, yoghurt, cheese, and ice cream. Enjoy soy milk drinks – ideally with an omega-3 content such as Soy Extra
Replace saturated fats with fats and oils rich in mono- and polyunsaturated fats; and carbohydrate-rich foods. Choose margarine instead of butter; and vegetable oils such as canola, olive, sunflower, soybean and Sunola instead of solid frying fats.
Eat less fat from meat and poultry. Choose lean cuts of meat and skinless chicken. Go easy on luncheon meats, salamis and fatty sausages. Enjoy fish.
Eat less saturated fats from baked and fried take-away foods. Avoid deep-fried foods, pies and sausage rolls. Go easy on cakes, pastries, biscuits/cookies. Choose lower fat take-aways. Home-made foods and dishes using healthier fats and oils are preferable.
3. Increase your soluble fibre intake. Foods rich in soluble fibre include dried beans, baked beans, lentils, chick peas, hummus nuts and seeds. Highest in soluble fibre are psyllium seed husks, psyllium-based cereals (e.g. Kellogg’s Guardian), and psyllium fibre supplements (e.g. Fybogel, Metamucil). Oat bran, rice bran and barley are also useful, as are fruit, vegies and avocados.
4. Eat more soya bean products, at least 25g of soy protein per day. Soy drinks, tofu, tempeh (cultured soya beans), soy flour, Longa Life and Sanitarium vegetarian products. Soy protein in place of animal protein can significantly decrease high blood cholesterol levels – as well as LDL-cholesterol and blood triglycerides. Protective HDL-cholesterol is maintained.
Soy also may protect against certain cancers, however, due to the way in which phystoestrogens in soy may react with certain treatment medications, people who have had breast cancer should always consult with a doctor before eating soy products or other phytoestrogen foods.
5. Eat more fruit and vegetables in place of high fat foods – they also contain valuable antioxidants which may help prevent oxidation of LDL cholesterol. Oxidised LDL-cholesterol increases the risk of damage to cells lining the arteries and may initiate the atherosclerosis process. The fat of avocados is mainly unsaturated and lowers blood cholesterol levels. Garlic can also help to lower blood cholesterol, and inhibit thrombosis.
6. Limit cholesterol to 300mg per day.
7. Spread out your food intake – have five or six small meals per day rather than just two or three large meals. Nibbling, rather than gorging, is better for lowering blood cholesterol.
Heart attack warning signals
Many victims die before reaching hospital because they ignoring warning signals and delay getting medical help. Symptoms vary and commonly include:
Chest pain, vice-like squeezing or burning sensation in the centre of the chest or between the shoulder blades, or a feeling like severe indigestion. The pain may spread to the shoulders, neck, jaw or arms.
Sweating, nausea, dizziness, shortness of breath, irregular pulse.
If you feel these yourself, or see someone else with these symptoms, call an ambulance. Even if it is just nasty indigestion, it’s better to be certain.