The Role of Cholesterol in Cardiovascular Disease
- Cholesterol is a complex, fatty substance that is mainly produced by the liver. Your body needs cholesterol to function normally.
- Diet only accounts for 20% of the cholesterol in your body. The remaining 80% is produced by your liver.
- Dietary cholesterol is found in foods such as organ meats (e.g. liver, kidneys, sweetbreads, brains), shrimp and egg yolks. Dietary cholesterol only has an effect in some people. Fats that raise your blood cholesterol the most are saturated and trans fats.
- Cholesterol is present in cell walls and membranes everywhere in the body, including the brain, nerves, muscle, skin, liver, intestines and heart.
- Your body uses cholesterol to produce many hormones and cell parts.
- However, when there is too much cholesterol in your bloodstream, the extra amount is deposited in your arteries, where it contributes to the narrowing and blockages that can lead to heart disease or stroke.
- Lipoproteins, which play the role of transport trucks, carry cholesterol and other fats through approximately 100,000 kilometres of blood vessels to various body tissues to be used, stored or excreted. There are several types of lipoproteins. Here are the most important ones to monitor for heart health.
Low-density lipoproteins (LDL)
- LDL molecules carry cholesterol from your liver to other parts of your body. Cholesterol carried by these molecules (LDL-cholesterol) is called “bad” cholesterol because it can lead to a build-up of plaque in the lining of the arteries. This can reduce blood flow, and may lead to the artery being fully blocked, which in turn can lead to a heart attack or stroke. Therefore, you want to have less LDL (“bad”) cholesterol.
High-density lipoproteins (HDL)
- HDL molecules gather up extra cholesterol from around your body and carry it back to your liver. Cholesterol carried by these molecules (HDL-cholesterol) is called “good cholesterol” because it won’t block your blood vessels. Therefore, you want to have more HDL (“good”) cholesterol.
- Triglycerides are the most common fat in the body, and high levels of triglycerides (another fatty substance found in the blood) have been linked to low levels of HDL-cholesterol, obesity and diabetes, which are all risk factors for cardiovascular disease. High triglyceride levels are associated with excess intake of simple sugars, refined carbohydrates, saturated fats, trans fats and alcohol. Triglycerides can be converted to LDL-cholesterol in your liver, so you also want to have lower levels of triglycerides in your blood.
What makes blood cholesterol high or low?
- Multiple factors play a role in causing high cholesterol, such as heredity, eating habits, physical activity, age and other medical conditions. It is important to remember however that eating habits on their own are not responsible for high cholesterol.
- A high LDL-cholesterol level means that you have more cholesterol in your blood than your body needs. The higher your LDL-cholesterol level, the greater your risk of developing coronary heart disease – the most common form of cardiovascular disease.
- Anyone can develop high LDL-cholesterol, no matter his or her age, weight, gender, race or ethnic background. High blood cholesterol has no warning signs. So, you may be surprised to know that you have it. Do not be alarmed, but do take it seriously. You can lower your LDL-cholesterol and significantly bring down your risk of cardiovascular disease.
Benefits of Cholesterol Lowering
- Lowering your LDL-cholesterol level can significantly decrease your chance of developing heart disease or stroke.
- Research has shown that for middle-aged men, a 1% decrease in total cholesterol can lead to a 2% decrease in the risk of cardiovascular disease.
- As a rule, people can lower their cholesterol levels by about 10-20% through lifestyle changes.
- To effectively manage high cholesterol, medication may be necessary in addition to lifestyle changes.