Since the type and amount of Cholesterol in our body can have important health effects on our cardiovascular system, it's a good idea to understand what Cholesterol is, how it affects our health and how to manage our blood Cholesterol levels. Such understanding helps us take better care of our heart and live a healthier life, reducing our personal risk for heart attack and stroke in the process.

What is Cholesterol?

Cholesterol is a waxy substance that belongs to the fat family or to a class of molecules called steroids. Cholesterol plays an important role in the body. It is an essential building material of the body's every cell and necessary for manufacturing a number of important hormones, bile and vitamin D that are essential for normal body functions. Cholesterol is naturally present in cell walls or membranes everywhere in the body, including the brain, nerves, muscles, skin, liver, intestines and heart.

What are the functions of Cholesterol?

• It builds and maintains cell membranes (outer layer), it prevents crystallization of hydrocarbons in the membrane
• It is essential for determining which molecules can pass into the cell and which cannot (cell membrane permeability)
• It is involved in the production of sex hormones (the body's chemical messengers e.g. Estrogens and Androgens)
• It is essential for the production of hormones released by the adrenal glands (cortisol, corticosterone, aldosterone and others)
• It aids in the production of bile. It converts sunshine to vitamin D and it insulates nerve fibers
• It is important for the metabolism of fat soluble vitamins, including vitamins A, D, E and K

Where does our body get Cholesterol from?

We get Cholesterol in two ways. The first source is the body itself, mainly the liver, which produces varying amounts, usually about 1000 milligrams a day. The second source is the food that we eat which is derived from animals (especially egg yolks, meat, poultry, whole-milk and dairy products). Foods from plants (fruits, vegetables, grains, nuts and seeds) do not contain Cholesterol. After a meal, Cholesterol is absorbed by the intestines into the blood circulation and is then packaged inside a protein coat. This Cholesterol-protein coat complex is called a chylomicron.

The liver is capable of removing Cholesterol from the blood circulation as well as manufacturing Cholesterol and secreting Cholesterol into the blood circulation. After a meal, the liver removes chylomicrons from the blood circulation. In between meals, the liver manufactures and secretes Cholesterol back into the blood circulation. Too much Cholesterol can have negative impacts on our health.

What are the different types of Fats in our Body?

Fats travel in the blood in two forms; Cholesterol and triglycerides.

Blood is watery and Cholesterol is fatty. Just like oil and water, the two do not mix. To travel in the bloodstream, Cholesterol is carried in small packages called lipoproteins. The small packages are made of fat (lipid) on the inside and proteins on the outside. There are two main types of lipoproteins: low-density lipoprotein (LDL) and high-density lipoprotein (HDL).

Low-density lipoprotein (LDL) is also known as 'bad' Cholesterol. LDL carries Cholesterol from the liver to cells. If too much LDL circulates in the blood, it can slowly build up on the walls of the arteries feeding the heart and brain and result in the formation of fatty streaks. These fatty streaks slowly increase in size and produce raised areas called fibrous plaques. Over the years these plaques increase in size and ultimately can block the blood flow to part of the heart and cause a heart attack. If the blood flow to the brain is blocked, a stroke can result.

High-density lipoprotein (HDL) is also known as 'good' Cholesterol as it helps so carry Cholesterol away from the arteries to the liver, where it is processed and excreted from the body. It removes excess Cholesterol from the blood thus providing protection against a heart attack or stroke. Thus, high levels of LDL Cholesterol and low levels of HDL Cholesterol (high LDL/HDL ratios) are risk factors for atherosclerosis, while low levels of LDL Cholesterol and high level of HDL Cholesterol (low LDL/HDL ratios) are desirable.

Triglycerides - these are the chemical forms in which most fat exists in the body, as well as in food. They are present in blood plasma. Triglycerides, in association with Cholesterol, form the plasma lipids (blood fat). Triglycerides in plasma originate either from fats in our food or are made in the body from other energy sources, such as carbohydrates. Calories we consume but are not used immediately by our tissues are converted into triglycerides and stored in fat cells. When our body needs energy and there is no food as an energy source, triglycerides will be released from fat cells and used as energy - hormones control this process.

How does high blood Cholesterol cause Heart Disease?

Our body makes all the Cholesterol that it needs. However, over a period of years, extra Cholesterol from the animal products that we eat builds up on the walls of the arteries in the form of plaques. These plaques gradually increase in size and make the arteries supplying blood to the heart narrower and narrower. As a result, less blood gets to the heart. Blood carries oxygen to the heart and if enough oxygen-rich blood cannot reach to heart, you may suffer chest pain called 'Angina'. If the blood supply to a portion of the heart is completely cut off the result is a heart attack.

Sometimes, plaques dislodge or produce a clot and obstruct the arteries resulting in 'Angina' or a heart attack. A raised level of Cholesterol has also been linked to other diseases including dementia and kidney failure.

Besides Cholesterol, a high level of triglycerides in the blood may also increase the risk of heart disease.

What makes our Blood Cholesterol High?

There ore several factors that can raise our blood Cholesterol level:

• Diet rich in saturated fats
• Obesity
• Physical inactivity
• Smoking
• Stress
• Alcohol
• Certain diseases e.g. diabetes, diseases of the kidney and the thyroid gland
• Use of oral contraceptives
• Increased age
• Gender - women during childbearing age usually have a lower Cholesterol level than those of men of the same age.
• Hereditary factors

What are the symptoms of High Blood Cholesterol?

Generally high blood Cholesterol itself does not cause any symptoms and that is why it is known as the "silent killer".

How is Blood Cholesterol measured?

It is recommended that every adult should be screened for blood Cholesterol. The Cholesterol level in the blood is measured in a sample token in the morning after a 12-hour fast.

It is best to have a blood test called a 'lipoprotein profile'.

This test gives information about our: Total blood Cholesterol, LDL (bad) Cholesterol, HDL (good) Cholesterol and Triglycerides.

What are the healthy levels of Cholesterol and Triglycerides?

Total Cholesterol is the sum of LDL (low density) Cholesterol, HDL (high density) Cholesterol, VLDL (very low density) Cholesterol and IDL (intermediate density) Cholesterol.

It is important to know that there are two main methods of describing concentrations of Cholesterol: by weight i.e. milligrams (mg) of cholesterol per deciliter (dL) of blood and by molecular count i.e. millimoles (mmol) of cholesterol per liter (L) of blood. To understand and describe the test results you should remember the units used for the measurement of your Cholesterol level. See how your cholesterol numbers compare to the tables below.

Triglycerides: Desirable value - Less than 150 mg/dL (less than 1.69 mmol/L)

Triglycerides can also raise your risk for heart disease. If you have levels that are borderline high (150-199 mg/dL) or high (200 mg/dL or more), you may need treatment.

What are the different types of Dietary Fats in the Food we eat?

Saturated fats are found mainly in foods of animal origin. Two vegetable oils, coconut and palm oil, are also high in saturated fat. It is the saturated fats that increase 'bad' (LDL) Cholesterol in the blood and cause narrowing and blockage of arteries.

Examples: Milk, butter, meat, palm oil, coconut oil, vegetable ghee.

Polyunsaturated fats occur in the oils of seeds and grains. Polyunsaturated fats are good for our heart as they decrease 'bad' (LDL) Cholesterol, but at very high levels they may also reduce the level of 'good' (HDL) Cholesterol. Therefore, they should be eaten in moderation.

Examples: Corn oil, Sunflower oil, safflower oil, Soya bean oil.

Monounsaturated fats are mainly found in plants. Monounsaturated fats are also good for our heart as they decrease 'bad' (LDL) Cholesterol and increase 'good' (HDL) Cholesterol. However, they should be eaten in moderation.

Examples: Olive oil, Canola oil, almonds, cashew nuts, peanuts, pistachio nuts.

Omega 3 fatty acids are a type of polyunsaturated fat that are mainly found in oily fish. They help reduce the risk of heart disease.

Examples: Tuna, kingfish, Salmon, Sardines.

Hydrogenated fats are made by adding hydrogen to polyunsaturated or monounsaturated fats to make the fat firmer and stop it going rancid. The process of hydrogenation effectively turns unsaturated fats into saturated fats and is commonly applied to fast foods.

Which cooking oil is good for our health?

We should choose oil rich in either mono or polyunsaturated fats because they help reduce blood Cholesterol. Examples of such oils are:

• Canola oil - rich in monounsaturated fat
• Corn oil - rich in polyunsaturated fat
• Sunflower - rich in polyunsaturated fat
• Safflower oil - rich in polyunsaturated fat
• Soya bean oil - rich in polyunsaturated fat

What can we do to control our Cholesterol level?

We should take the following steps in order to help control our blood Cholesterol level and lower our chance of heart disease.

Choose the right Foods

• Avoid foods rich in saturated fat
• Remove the skin and fat from meat and poultry
• Eat fish at least twice weekly
• Boil, bake, roast or poach instead of frying foods
• Use monounsaturated and polyunsaturated oil for cooking. Use them in moderation
• Use skimmed or low-fat milk, cheese and yoghurt
• Avoid doughnuts, muffins, pastries and fast food
• Eat fruits, vegetables, nuts, cereals, bread, rice and pasta
• Use liquid or soft margarine instead of butter
• Eat more egg whites and less egg yolks
• Read food labels so learn how much fat is in the food you eat
• Try to reduce your sugar intake

Do regular exercise

Regular physical activity is recommended for everyone. It can help raise 'good' (HDL) Cholesterol and lower 'bad' (LDL) Cholesterol and also help to control our body weight.

• Start slowly and progress gradually. Our goal is to be active every day.
• Plan to be active for at least 30 minutes every day.
• Activities should be moderate in intensity. These activities should make you breathe faster than normal, like when you are walking quickly. But don't overdo it. Make sure that you can still talk easily.
• You don't have to do 30 minutes of activity all at once. You can work up to this by doing small amounts several times a day. Try to do at least 10 minutes of activity each time.
• Choose activities that you enjoy and that are right for you. The best ones are those that use the large muscles, especially those in the legs. When these muscles working, they require more oxygen, so the heart has to beat faster. This way you heart becomes a stronger, more efficient pump.
• Before you start an activity program, talk with your doctor and get advice.

Control your body weight

Check your Body Moss Index (BMI) to determine if your weight is correct for your height. You can check your BMI by the following formula:

BMI = Weight (Kilogram) / Height (meters) X Height (meters)

If your BMI is less than 18.5, you ore considered underweight.

If your BMI is from 18.5 and 24.9, you are considered to be in a healthy weight range for your height.

If your BMI is between 25 and 29.9, you are considered overweight.

And, if your BMI is 30 or greater, you are considered obese.

Stop Smoking

Smoking doubles our risk of heart disease and stroke. It lowers 'good' (HDL) Cholesterol and raises bad (LDL) Cholesterol. Smoking also increases the risk of developing lung cancer. There is really only one way to lower these risks: stop smoking.

Passive smoking is also dangerous for health. Children are at particular risk due to adults smoking and can develop adverse health effects including coughing, pneumonia, bronchitis, worsening of asthma, middle ear disease and possibly heart disease in adulthood.

Women who smoke or are exposed to other people smoking have a greater risk of having a miscarriage, premature birth and low birth weight babies.

Talk to your healthcare provider about a stop-smoking program.

Quitting smoking is the single most important step that you can take to safeguard your health.

Manage your Stress

Stress over the long term has been shown to raise blood Cholesterol levels. One way that stress may do this is by affecting your habits. For example, when some people are under stress, they console themselves by eating fatty foods. The saturated fats in these foods contribute to higher levels of blood Cholesterol.

Medications for lowering Cholesterol Levels

If the above measures don't lower your Cholesterol levels enough, your doctor my also prescribe medication. Be sure to take it exactly as directed.

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