Cholesterol and Diseases
CHOLESTEROLThere are four types of lipids: neutral fats, free fatty acids, steroids and phospholipids. Cholesterol is a steroid produced within the liver cells and has vital roles in the normal functioning of the human body. Cholesterol is transported in blood via compounds made up of proteins and fats, lipoproteins. Basically, lipoproteins are categorized into three main groups based on density:- HDL – These are lipoproteins of high density. They transmit cholesterol from blood into the liver. Consequently, they are also termed as good cholesterol.
- LDL – These lipoproteins are of lower density compared to the HDL. They carry cholesterol into the blood from the liver hence called bad cholesterol.
- VLDL – They have the lowest density of all the lipoproteins. They carry triglycerides into adipose tissue through blood from the liver. They are also called blood lipids.Functions of cholesterolThere are multiple functions related to cholesterol:• It is an essential element of cell membranes
• It is a precursor substance of estrogen and androgen, sex hormones
• Helps in the synthesis of bile, a substance responsible for digestion of fats
• It’s a nerve fiber insulator
• Synthesize vitamin D from sunshine
• Metabolize vitamins soluble in fats, that is, vitamins E, A, D and KNevertheless, cholesterol is harmful when synthesized in excess in the body. It is the causative agent of a number of diseases including hypertension, arteriosclerosis, impaired sight and cardiovascular diseases.How diseases develop out of cholesterolPeople with elevated levels of LDL such as the diabetics and the alcoholics are vulnerable to these diseases. As stated earlier, these lipoproteins release cholesterol into blood. Cholesterol in blood builds onto blood vessels. This reduces the lumen of the vessels. The blood volume however remains the same, and has to be pumped at a much higher force therefore causing high blood pressure.Cholesterol may combine with calcium in blood and build up onto arteries. This causes the artery to become rigid a condition known as arteriosclerosis. Such an artery looses its ability to pump blood and easily tears off.Additionally, cholesterol in blood may accumulate in sensitive organs such as in the eyes. Here, they combine with rhodopsin, a pigment for sight. This pigment becomes impaired and cannot allow light to pass through it. Another vital organ where cholesterol may accumulate is on nerve tissues. The tissue becomes damaged in such a way that they can not effectively transmit impulse. This disease is called neuropathies.