Cholesterol (chole-bile and stereos-solid) is a type of lipid (fat) in your blood. It is vital for the body as it is required to build and maintain cell membranes and acts as a precursor for the biosynthesis of steroid hormones, bile acids, and, vitamin D.
Sources of Cholesterol
It comes from two sources:
1. Your body:
- Your liver and other cells in your body make up about 75 percent of blood cholesterol
- The remaining 25 percent comes from the food you eat (known as dietary cholesterol). Cholesterol is mostly found in animal products. Main dietary sources of cholesterol include cheese, egg yolks, beef, pork, poultry, fish, and shrimp. Human breast milk also contains significant quantities of cholesterol
Cholesterol and Lipoproteins
it is a type of lipid (fat) that is insoluble in water and therefore, is incapable of dissolving in the blood (which is mostly water). To be carried in the blood, it combines with specific proteins to form a substance known as a lipoprotein.
There are various kinds of lipoproteins in the body that carry it:
1. LDL (Low-Density Lipoprotein) Cholesterol
carries it from the liver to the cells of the body. It is also known as ‘bad cholesterol’ as it is the main source of cholesterol buildup and blockage in the arteries. An LDL-cholesterol level of less than 100 mg/dL is considered optimal and has a very low risk for Coronary Heart Disease (CHD). LDL levels between 100-129 mg/dL put you at a higher risk of developing atherogenesis and may accelerate if your LDL levels exceed more than 190 mg/dL
2. HDL (High-Density Lipoprotein) Cholesterol
- carries it away from the arteries and back to the liver, where it’s removed from your body. It is also known as ‘good cholesterol’ as it removes excess from an arterial plaque, slowing its build-up and protecting against heart attack. That is the reason why high levels of HDL cholesterol (more than 60mg/dL) are believed to have beneficial effects in protecting against heart attack. On the other hand, low levels of HDL cholesterol (less than 40 mg/dL for men and less than 50mg/dL for women) may increase your risk of heart disease
3. VLDL (Very-LOw Density Lipoprotein) Cholesterol:
- They are triglyceride-rich lipoproteins that enable them to move within the water-based solution of the bloodstream. Some forms of VLDL appear to promote plaque buildup (atherosclerosis), similar to LDL (bad) cholesterol
- They are triglyceride-rich lipoproteins and are formed in the intestine from dietary fat and appear in the blood after a fat-containing meal and probably contribute to some extent to plaque formation