Cholesterol is a soft, fat-like substance normally present in body cells, tissues, and blood. It is an essential component of cell membranes and is vital to the structure and function of body cells. Cholesterol is also a building block in forming some hormones for regulating vital body functions and bile acids for digesting foods. Only a small amount of cholesterol is necessary to maintain healthy body functions.
However, abnormally high levels of cholesterol in the blood will build up on the arteries, leading to coronary artery disease, particularly a heart attack. Thus, elevated cholesterol is a major coronary risk factor.When the cholesterol level increases from 175 to 300 mg/dL, the risk of heart attack increases by almost 4 times.
Cholesterol is made in the body, mostly in the liver, and is also found in various foods from animals (e.g., meat from four-legged animals and poultry, fish, and dairy products). Egg yolk also contains lots of cholesterol. On the other hand, egg white, fruits, vegetables, and nuts and seeds contain no cholesterol.
Cholesterol has to circulate to and from the cells through the bloodstream, but cholesterol and other fats cannot be dissolved in the blood. So, cholesterol has to travel by special carriers called lipoproteins. Although there are several kinds of lipoproteins, the two most important are low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
Normal (desirable) and abnormal (high) total blood cholesterol level ranges are as follows:
- Less than 200 mg/dL: desirable
- 200 to 239 mg/dL: borderline high
- 240 mg/dL and higher: High
People with borderline high cholesterol levels (200–239 mg/dL), have twice the heart attack risk. It is recommended to limit daily cholesterol consumption to not more than 300 mg. Depending upon the levels of total cholesterol, particularly LDL cholesterol, you should markedly reduce or even avoid the consumption of foods containing large amount of saturated fats as much as possible.