Discuss the role of dietary cholesterol and the endogenous production of cholesterol and heart disease. What is meant by "good" and "bad" cholesterol?

Question

What will be an ideal response?

Answer 1

Foods derived from both plants and animals contain sterols, but only those from animals contain significant amounts of cholesterol—meats, eggs, seafood, poultry, and dairy products. Some people, confused about the distinction between dietary cholesterol and blood cholesterol, have asked which foods contain the "good" cholesterol. "Good" cholesterol is not a type of cholesterol found in foods, but it refers to the way the body transports cholesterol in the blood, as explained in a later section of this chapter.

Sterols other than cholesterol are naturally found in plants. Being structurally similar to cholesterol, plant sterols interfere with cholesterol absorption. By inhibiting cholesterol absorption, a diet rich in plant sterols lowers blood cholesterol levels. Food manufacturers have fortified foods such as margarine with plant sterols, creating a functional food that helps to reduce blood cholesterol.

Many vitally important body compounds are sterols. Among them are bile acids, the sex hormones (such as testosterone androgen, and estrogen), the adrenal hormones (such as cortisol cortisone, and aldosterone), and vitamin D, as well as cholesterol itself. Cholesterol in the body can serve as the starting material for the synthesis of these compounds or as a structural component of cell membranes; more than 90 percent of all the body's cholesterol is found in the cells. Despite common misconceptions, cholesterol is not a villain lurking in some evil foods—it is a compound the body makes and uses. The chemical structure is the same, but cholesterol that is made in the body is referred to as endogenous, whereas cholesterol from outside the body (from foods) is referred to as exogenous. Right now, as you read, your liver is manufacturing cholesterol from fragments of carbohydrate, protein, and fat. In fact, the liver makes about 800 to 1500 milligrams of cholesterol per day, thus contributing much more to the body's total than does the diet. For perspective, the Daily Value on food labels for cholesterol is 300 milligrams per day.

Cholesterol's harmful effects in the body occur when it accumulates in the artery walls and contributes to the formation of plaque. These plaque deposits lead to atherosclerosis, a disease that causes heart attacks and strokes.