Alternative Names total cholesterol, LDL cholesterol, HDL cholesterol, blood lipids, dietary cholesterol, blood or serum cholesterol
Definition Cholesterol is a transport molecule. It packages and shuttles fatty substances around the body. Blood cholesterol levels are influenced by two factors. One is the food a person eats. The second is how much cholesterol his or her body makes. Cholesterol is made by the body in the liver. So not only do people get cholesterol from food but also from the body.
What food source is the nutrient found in? Foods high in saturated fats, mostly animal foods, such as cheese, fatty meats and butter, tend to be high in dietary cholesterol. Only animal foods contain cholesterol. Some foods such as nuts have no cholesterol even though they are high in fat.
1 egg yolk = 180mg
100g lean beef, pork, chicken, lamb = 60-70mg
1 cup skim milk = 8mg
1 cup milk = 33mg
1/2 cup avocado = 0mg
1/2 cup nuts = 0mg
Cholesterol is unique to animal-derived foods. It is not present in plant-derived foods, unless it has been added. For most people, it is the amount of saturated fat in their diets, not the amount of cholesterol in certain foods that raises blood cholesterol levels. Regardless, the Heart Foundation suggests that people moderate their dietary cholesterol intake and keep total fat to 30% or less of the day's total kilojoules. Saturated fat including trans fats should only be 8 percent of the 30 percent allowed for total fat.
How does the nutrient affect the body? Although it sometimes has a bad reputation, cholesterol is important to our body. It is the building block for many sex hormones, such as oestrogen. As a fat transport molecule, it carries important nutrients to different parts of the body. It also helps rid the body of fatty waste products, a function that when sluggish causes a rise in blood cholesterol levels. Cholesterol is important as part of a body chemical called bile. Bile helps the body digest and absorb fat. Sunlight can help cholesterol in your skin change to vitamin D, a nutrient that is essential for bone building.
Most Australians need to be concerned about blood cholesterol levels that are too high rather than too low. Too much cholesterol in the bloodstream is linked to heart disease. This means that, like smoking or family history, cholesterol on its own can increase a person's risk for developing heart disease.
Information A blood lipid test will provide information about a person's:
Measurements are expressed as millimoles of lipid per litre of blood (mmols/L).
A total cholesterol reading below 5.0 mmols/L (millimoles per litre) is desirable; 5.0 - 6.0 mmols/L is borderline; over 6.0 mmols/L is considered high.
HDL is considered good cholesterol. HDL carries cholesterol back to the liver, where it is broken down and excreted. This helps reduce total cholesterol levels. HDL is the type of cholesterol that should be high. HDL levels below 1.0 mmols/L are considered to put a person at higher risk for heart disease. Weight loss and exercise are the best ways to increase HDL levels.
LDL cholesterol, on the other hand, should be kept low. Doctors suggest an LDL level of 2.5 mmols/L or lower. LDL levels over 4.0 mmols/L increase risk for heart disease. LDL is responsible for carrying cholesterol from the liver to body cells. On the way, it forms deposits on the walls of arteries and blood vessels. This creates the buildup of fatty plaques, which obstruct the arteries, and may cause heart disease.
HDL and LDL are found only in the bloodstream. They are not found in food. Food choices will influence HDL and LDL levels. If saturated fat and cholesterol are lowered in the diet, LDL levels will most likely come down.
There are several drugs available to help keep LDL and total cholesterol levels low. But the first step is a lifestyle approach. The heart foundation recommends losing weight, if needed, and eating a diet low in fat, cholesterol and saturated fat and high in fibre. If a person is not able to lower blood cholesterol levels by changing their lifestyle, then their doctor may suggest cholesterol-lowering medication, such as simvastatin or atorvastatin. Monounsaturated fats, such as those found in olive and nut oil, show some protection against elevated cholesterol levels, as do garlic and soy oil.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
