Cholesterol, an integral part of each cell in the body, is a waxy, fat-like substance that is made in the body by the liver. The body can make all the cholesterol it needs from the fats in the diet. Cholesterol serves many vital functions in the human body. Our bodies need cholesterol to:
- Maintain healthy cell walls
- Make hormones (the body’s chemical messengers)
- Make vitamin D
- Make bile acids, which aid in fat digestion
However, the body sometimes makes more cholesterol than is really needed. As a result the excess cholesterol circulates in the bloodstream. High levels of cholesterol in the blood can cause the blood vessels to clog as well as increase the risk for heart disease and stroke.
Types of Cholesterol
In order to reach the cells, cholesterol travels through the bloodstream. But because cholesterol is a fat, it separates from the blood just as oil separates from water. To keep this from happening, proteins form a shell around the cholesterol, making a ‘cholesterol complex.’ This cholesterol complex can then travel in the bloodstream. Although there is only one type of cholesterol, there are several types of cholesterol complexes and not all are harmful.
There is a ‘bad’ kind and there is a ‘good’ kind. The ‘bad’ cholesterol is called LDL (Low-Density Lipoprotein) and the ‘good’ cholesterol is called HDL (High-Density Lipoprotein). The bad cholesterol tends to block the arteries, increasing the risk for heart disease and stroke; but the good cholesterol helps clean up the bad cholesterol inside the arteries. The third is the VLDL (Very Low-Density Lipoprotein)
LDL is almost all cholesterol and helps transport cholesterol to the tissues that need it. VLDL, on the other hand, has a lot of triglycerides along with cholesterol, and this helps transport triglycerides to the cells that need it. HDL, which is also mostly cholesterol, helps picks up the extra cholesterol and brings it to the liver, where it is either stored for future use or discarded. That is why it is considered to be good cholesterol.
Risks of having High Cholesterol
The liver makes most of the cholesterol in the body – only a small percentage comes from food. But the more saturated fat we eat, the more cholesterol our bodies make. Blood cholesterol levels in most people can be controlled without medication – simply change to a healthy diet and become more active. Eat only plant foods as they do not contain cholesterol; animal foods must be eaten in moderation.
High Cholesterol levels may cause problems. The extra cholesterol can deposit in the arteries and lead to blocked arteries. If this happens to the artery that supplies blood to the heart, a heart attack can occur. Similarly, if the artery supplying blood to the brain gets blocked, a paralytic stroke can occur. Therefore, the higher the cholesterol, the greater is the risk of heart disease and stroke.
These cholesterol-rich deposits become coated with scar tissue, forming a bump in the blood vessel known as plaque. Plaque buildup can narrow and harden the blood vessels - a process that is called atherosclerosis, or hardening of the arteries.