Cholesterol Essay

This essay has a total of 1568 words and 7 pages.

cholesterol



For years, cholesterol has been a major concern for millions of people around the world.
This fear of cholesterol has led to many consultations with specialists like physicians
and nutritionists. It seems that there is a great misconception about this molecule. A
majority of the population is conscious of the harm that it can cause, but they are not
aware that it has pertinent values to our body. There are two major forms that cholesterol
comes in: 1) low density lipoprotein, which is generally considered "bad" cholesterol and
2) high density lipoprotein, which is known as "good" cholesterol. Although given these
names, there is nothing inherently good or bad about them. This research will clarify a
lot of the misconceptions that are associated with cholesterol and the overall effect that
cholesterol has on the human body.

Cholesterol is a soft, fat like substance made up of carbon, hydrogen, and oxygen, that is
found in all the body's cells and is used to form cell membranes, manufacture hormones and
other necessary substances. It is an organic compound belonging to the sterol family that
also encompasses steroids.

Cholesterol is produced two ways. The first is by the liver. "The liver produces about
50,000,000,000,000,000 cholesterol molecules a second" (Body Mechanics 1), or about 1,000
mg of cholesterol a day. The second is by the intake of the foods eaten like animal fats
(saturated and polysaturated fats) such as cheese, lard, egg yolks, red or marbled meat,
pork, processed meat, gravies, palm or coconut oil, deep fried foods, whole milk, butter,
etc.. This second process is accountable for another 400 mg - 500 mg of cholesterol a day.

Once eaten, the cholesterol in the food goes into the intestines to await digestion.
"Chylomicrons (fatty particles containing mainly triglycerides, but also cholesterol,
phospholipids and protein) are produced in the intestinal wall" (Arthersclerosis 3). Once
the chylomicrons enter the bloodstream, they bind to receptors on the capillaries. A large
percentage of triglycerides is broken down and released into circulation. "The remainder
of the chylomicron (the 'chylomicron remnant'), now richer in cholesterol, continues in
circulation until it reaches the liver and is absorbed (Athersclerosis 3). Since
cholesterol is like a fat, it is hydrophobic and unable to mix with water or blood. In
order for it to be carried through the blood, the liver the combines the cholesterol with
triglycerides and proteins (called lipoproteins) to form packages called very low density
lipoproteins (VLDL). These packages, which account for 10-15 percent of the cholesterol in
the body, are dispersed into the bloodstream and are "transported to tissue capillaries
where triglycerides are broken down and either used for energy or stored by muscle or fat
cells" (Athersclerosis 3). After the release of the triglycerides, the package now has a
higher percentage of cholesterol. This package is now called low density lipoproteins or
"LDL".

LDL's, also known as the "bad" cholesterol, is transported through the bloodstream to
build cells, make hormones, and act as an insulation for nerves. Low density lipoproteins
account for "60-70 percent of the total serum cholesterol" in the body (ATP: Chapter 1 1).
This package of cholesterol is very useful to the body. It is necessary in the membranes
of cells. If the cell gets too cold, the cholesterol kept the cell from freezing or
turning solid. Conversely, as the cell gets too hot, the cholesterol keeps the cell from
melting. This so called "bad" cholesterol, maintain the cell's fluidity. Once the LDL's
have completed their tasks, they are removed from the body though the bloodstream to the
liver. However, this removal process can occur at slower rates in certain people than
others. This causes a build up of the cholesterol within the walls of the arteries. This
build up, over time, can slow down or even prevent the circulation of blood to the heart
and brain and can cause such disorders as Atherosclerosis, in which "deposits of
cholesterol and other fatty substances circulating in the blood accumulate in the interior
walls of the blood vessels", and hypercholesterolemia, which is an elevated level of
cholesterol in the blood, and ultimately coronary heart disease (CHD), which causes heart
attacks (Britannica Online 1). This is where the LDL's get their "bad" reputation.


In addition to VLDL's and LDL's, there is another form of lipoprotein called high density
lipoprotein or "HDL". This package, which counts for 20-30 percent of the bodies total
blood cholesterol, is also synthesized in the liver but it contains a higher percentage of
triglycerides and a lower percentage of cholesterol. It is believed by many researchers to
be "good" cholesterol because whereas low density lipoproteins are sent through the
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