We need cholesterol to make bile salts, hormones and vitamin D. It is mainly produced by the liver. Cholesterol will build up on the artery walls and when the level of cholesterol in the blood is too high this can lead to angina, heart attacks or a stroke. There are 2 main types of blood cholesterol: LDL (the “Bad” cholesterol) and HDL (the “Good” cholesterol).
High amounts of the bad LDL will deposit cholesterol on the artery walls forming plaques. More and more plaques will narrow the arteries and may eventually reduce or block blood flow. Saturated fats and trans fatty acids are the most important factors that raise blood cholesterol, not dietary cholesterol! Monounsaturated fats and polyunsaturated fats found in nuts and fish for instance can lower the LDL level. In addition, soluble fibre found in fruits, oats, barley and legumes could also lower LDL.
The good HDL, on the other hand, takes excess cholesterol away and carries it back to the liver to be excreted. It can also remove some of the cholesterol already attached to the artery walls. Therefore HDL is considered the “Good” cholesterol as high levels of HDL in the blood can decrease the risk of heart disease. Physical activity can also raise HDL level.
There are also Triglycerides (the “ Ugly”) which is the main form of fat in foods. They will be processed by the liver after eating. It is normal for blood to contain certain levels of triglycerides. However, if you consume excess calories regardless of the source – carbohydrates, fats or protein, the body will transform excess calories into triglycerides for storage as body fat in the adipose tissue. Therefore it is more common to see high triglycerides in overweight or obese individuals. Similar to the LDL cholesterol, high triglycerides is associated with increased risk of heart disease.
To have a complete picture of your blood cholesterol levels, your doctor can complete a blood cholesterol test. If you are 20 or older, you should check your cholesterol level at least once every 5 years. It’s desirable to have your cholesterol numbers within the desirable range. Levels in between are considered borderline high.