Innumerable studies confirm that having too much of the wrong type of cholesterol can be a silent harbinger of drastic things to come, such as cardiovascular disease and possibly fatal heart attack.

There’s plenty of incentive to do something about unhealthy cholesterol readings, given that a 1 per cent reduction in cholesterol brings a 2 per cent reduction in the risk for heart attack.

In some ways, cholesterol has received an undeservedly bad rap. This white, waxy, fatty substance that circulates through the bloodstream is actually vital for good health. Every human cell is encapsulated in a fatty cellular membrane made with the aid of cholesterol. Cholesterol also plays an essential part in the production of sex hormones.

While we all know that cholesterol levels can be too high, it might surprise you to know that they can also be too low. Cancer patients with low cholesterol are at increased risk of death. In addition, there is evidence that people with seemingly enviably low cholesterol are more prone to anxiety, depression and low levels of the feel-good hormone serotonin.

FRIEND OR FOE?

Most people associate cholesterol with eggs and fatty foods, but in truth only 20 per cent of our total cholesterol comes from what we eat; the body itself produces the remaining 80 per cent.

When it comes to understanding the pros and cons of cholesterol, it’s all about balance. Cholesterol becomes a health hazard only when you have too much of it, or when you have too much of the potentially troublesome LDL form of cholesterol. Then it can easily cling to artery walls, silting up the arteries and causing them to narrow and harden. Eventually, this fatty plaque can break away and travel to the heart, causing a heart attack, or it may lodge in arteries near the brain, causing a stroke. This is even more likely if you have a family history of cardiovascular disease or you suffer from high blood pressure.

Cholesterol is transported through the bloodstream on the back of protein molecules called lipoproteins. Low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) assume the mantle as the cholesterol villains. LDL is highly loaded with an unstable form of cholesterol, which it transports around the body. When LDL levels are too high, this unstable form of cholesterol ends up clinging to the lining of the arteries.

High-density lipoprotein (HDL), on the other hand, is your friend. The higher your HDL levels, the lower your risk for cholesterol-related cardiovascular disease. HDL works like a vacuum cleaner, removing the fatty deposits of LDL from the arteries and carrying them off to the liver, where they are broken down, ready to be excreted from the body.

The other type of blood fat, or lipid, usually tested along with cholesterol is triglyceride. This is the most common form of fat in foods and the human body. Whenever your body doesn’t immediately use all the calories in a meal, they are converted to triglycerides and shunted off to be stored in fat cells. High triglyceride levels are also thought to increase your risk for heart disease, especially if accompanied by high LDL cholesterol.

CALCULATED RISKS

So how do you interpret your cholesterol test results? There was a time when your total cholesterol level (LDL and HDL added together) was the most important reading, with anything higher than 4mmol a litre considered a warning. Today, while the total cholesterol level is still considered important, the ratio of 
LDL to HDL cholesterol is of equal or greater significance. So if your total cholesterol levels are high but you have plenty of protective HDL cholesterol (more than 1mmol a litre), along with a lack of other obvious cardiovascular risk factors, your risk for cardiovascular disease may still be considered low.

Cholesterol readings are never considered in isolation when estimating an individual’s risk for cardiovascular disease; together with other parameters they can create a more accurate picture of risk. If you’re a fit, slim, active non-smoker and your total cholesterol reading is greater than 5.5mmol a litre, there is probably no cause for panic, especially if your protective HDL levels are good. Your other risk factors for heart disease are low, so your overall risk, despite your seemingly high cholesterol, is also low. However, in an overweight smoker with diabetes and high blood pressure, the same cholesterol reading would probably be considered a ticking time bomb.

IDEAL CHOLESTEROL READINGS

Total cholesterol: less than 4mmol a litre

LDL: less than 2.5mmol a litre

HDL: greater than 1mmol a litre

Total cholesterol to HDL ratio: less than 4.5

LDL to HDL ratio: less than 3

Triglycerides: less than 2mmol a litre

TIPS FOR LOWERING LDL CHOLESTEROL

- Reduce your intake of saturated fats (present in dairy, red meat and palm oil).

- Reduce your intake of trans fats (in commercially baked pies, biscuits, pastries, cakes and snack foods).

- Lose weight and maintain an optimum body mass index (BMI).

- Increase your intake of soluble fibre (in oats, barley, apples, oat bran, lentils, legumes, peas and flaxseed).

- Take a heaped teaspoon of psyllium (high in soluble fibre) stirred into a glass of water, twice a day.

- Don’t smoke.

- Statin drugs are used to lower LDL cholesterol (note they do not increase HDL cholesterol).

TIPS FOR BOOSTING

HDL CHOLESTEROL

- Follow the tips above for lowering 
LDL cholesterol.

- Exercise aerobically for at least 
30 minutes (preferably 45 minutes) 
three or more times a week.

- Enjoy an occasional glass of red wine.

- Reduce your intake of high glycemic index (GI) carbohydrates such as refined grains and sugars.

- Increase your intake of low GI carbohydrates such as whole grains, lentils, beans, fruits and vegetables.

- Consume omega-3 and omega-9 fats (instead of saturated fats) in oily fish (salmon, sardine, herring, tuna and mackerel), nuts, seeds, flaxseed, flax oil and extra-virgin olive oil.

- Avoid an ultra-low-fat diet, as it will decrease HDL levels.

- Include soy products in your diet.