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Cholesterol

When we hear about cholesterol, we think of it building up in our arteries and contributing to long-term health problems. But it isn’t a ‘bad guy’—healthy levels of cholesterol are vital for our cells to function and to make vitamin D and some hormones.

There are two main types of cholesterol—HDL (good cholesterol) and LDL (bad cholesterol).

  • HDL cholesterol is known as ‘good’ cholesterol as it helps to remove cholesterol from the arteries by carrying cholesterol back to the liver for disposal.
  • LDL cholesterol is known as ‘bad’ cholesterol, as it leaves cholesterol in the arteries.

People with diabetes generally have similar total cholesterol levels and similar rates of the ‘good’ (HDL) cholesterol as the general population. But, on an average, they also have higher levels of the ‘bad’ (LDL) cholesterol and higher levels of triglycerides than people without diabetes. This is because diabetes can upset the balance between ‘good’ (HDL) and ‘bad’ (LDL) cholesterol levels in a number of ways.

  • People with diabetes tend to have ‘bad’ cholesterol particles that stick to the arteries and damage their walls more easily.
  • High levels of glucose in the blood can result in ‘bad’ cholesterol staying in the bloodstream for longer.
  • People with diabetes tend to have low HDL and high triglyceride (another blood fat) levels, both of which boost the risk of heart and artery disease.

This means that people with diabetes are at a higher risk of:

  • heart disease, including heart attack and stroke
  • circulation problems that can lead to damage to hands, feet and legs

What is a cholesterol test?

Your doctor may test your cholesterol level (blood fats) as part of your diabetes health check. Although some cholesterol is needed for your body to function, too much cholesterol can lead to health problems.

The total cholesterol test is a blood test that measures both HDL and LDL cholesterol.

Triglycerides are a type of fat in your blood, that can also increase your risk of heart disease.

Triglycerides are usually tested along with cholesterol when you have a cholesterol blood test. The tests for total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides are known as a lipid profile.

How are you going with your diabetes health checks?

Regular checks can help prevent serious diabetes complications like problems with your feet, eyes, heart and kidneys. Individual members of your health care team will let you know how often you need checks, so you can schedule them into your calendar.

Improving blood cholesterol

There is strong evidence to suggest that lifestyle changes, like following a healthy diet and doing regular physical activity, can significantly improve the blood cholesterol levels of people with diabetes.

In Australia, eating less saturated fat is one of the most practical ways to lower cholesterol. Low cholesterol or cholesterol-free foods may be useful for some people, but check that they are also low in saturated fat.

You should focus on eating less saturated fat rather than less cholesterol, because saturated fats more often effect blood cholesterol levels and many of the foods that are high in saturated fat are also high in cholesterol.

If a food does make a low-cholesterol claim, check the amount of saturated fat on the nutrition panel of the food label.

  • For oils, margarines and other similar foods that are nearly 100% fat, look for those with less than 20g of saturated fat per 100g.
  • For other foods, if they have less than 2g of saturated fat per 100g they are probably a good choice for your blood cholesterol.

It is worth noting that most of the foods that are high in cholesterol are from animals, because cholesterol is manufactured in the liver. So low-cholesterol claims on rice and bread are pretty meaningless! However, some plant-based foods have animal fats added to them when they are prepared, like many biscuits and cakes, so some can contain significant amounts of cholesterol.

If you try a low saturated fat diet for a few months and it doesn’t improve your blood cholesterol levels enough, you should try reducing your dietary cholesterol for another couple of months.

Food to improve blood cholesterol

People with diabetes living in Australia get around 35% of their total energy from fats and oils, although the optimal intake has been recently suggested as less than 30%. Reducing your total fat intake can help lower your total blood cholesterol level, provided you don’t replace the fats with high-glycemic index (GI) carbohydrates.

Eating less fat is not enough in itself to achieve optimal cholesterol levels. It is equally important that the right kinds of fats are consumed regularly. On an average, Australians with diabetes get about 13% of their total energy from saturated fats, when they should be consuming less than 10%. Practical ways of reducing the amount of saturated fat you eat include:

  • choose reduced-fat or low-fat milk, cheese, yoghurt, ice cream and custard
  • choose lean meat and chicken and trim/remove any fat before cooking
  • avoid butter, lard, cream, sour cream, copha, coconut milk, coconut cream and hard cooking margarines
  • limit pastries, cakes, puddings, chocolate, cream biscuits and savoury packet snacks to special occasions
  • limit the use of processed deli meats for example devon, polony, fritz, luncheon meat, chicken loaf, salami and sausages
  • avoid take away foods such as chips, fried chicken, battered fish, pies, sausage rolls and pastries
  • choose tomato and soy-based sauces rather than creamy sauces and avoid creamy style soup.

Dealing with triglycerides

Triglyceride is a type of fat found in the blood. It is the main component of vegetable oil and human and animal fats. People with diabetes typically have higher than average levels of triglycerides. This happens as raised glucose levels in the blood makes it harder for the body to absorb fat from the bloodstream.

Dietary factors that raise triglyceride levels include:

  • eating too many high-GI carbohydrates
  • drinking too much alcohol—that is more than two standard drinks a day for women and four for men. While lower alcohol limits are recommended to prevent liver and organ damage, keeping alcohol intake below these levels will minimise the impact on triglycerides.
  • not having enough omega-3 fat—omega-3 fats can be found in oily fish, such as herring, mackerel, sardine, salmon and tuna. They are also found in certain nuts and seeds and products made from these, such as flaxseed, canola, walnut, wheat germ and soybean oils as well as margarine. Aim to consume two to three serves of fatty fish a week. Try using canola or soy-based spreads and oils including a couple of handfuls of nuts a week, preferably walnuts.

Other diet-related factors

Body weight and blood glucose levels have independent effects on cholesterol levels. Therefore, losing a moderate amount of weight (5–10% of your initial body weight) and eating the right amount and type of carbohydrates will help you achieve optimal results.

For more information contact the Heart Foundation.

Read more about heart disease.