Prof. J.P.N. Mishra
Structurally steroids are different from other lipids cholesterol is an important steroid; it is made of four rings of carbon and hydrogen (not fatty acids and glycerol). The liver synthesizes cholesterol, in addition to the cholesterol we eat in food as part of our diet. Cholesterol is another component of cell membranes and is the precursor (raw material) for the synthesis of other steroids. In the ovaries or testes, cholesterol is used to synthesize the steroid hormones estrogen or testosterone, respectively. A form of cholesterol in the skin is changed to vitamin D on exposure to sunlight. Liver cells use cholesterol for the synthesis of bile salts, which emulsify fats in digestion. Despite its link to coronary artery disease and heart attacks, cholesterol is an essential substance for human beings (Seeley, 2003).
A high quantity of cholesterol in the bloodstream is one of the major factors, along with smoking and high blood pressure, contributing to coronary heart disease, the nation's leading cause of death. How this risk factor relates to anyone individual's health and life-style, however, is a far more complex matter. Cholesterol is not an immediate threat to the entire population, as some would claim; nor is it a "myth" generated by overzealous public health officials and medical experts, as others have contended. In reality, elevated blood cholesterol does impart an increased risk for the development of coronary heart disease. The extent of this increase in risk depends on the degree of the cholesterol abnormality, together with other factors, including heredity, age, and gender. The presence of other coronary heart disease risk factors, such as high blood pressure, smoking, or diabetes, will also affect risk. The final determination of how to handle the cholesterol question rests with an individual and his or her physician.
