Hypercholesterolemia - Familial

Cholesterol-- the good, the bad and the ugly

Introduction:

Most of your students should have at least some knowledge about cholesterol. Most probably feel it has a negative connotation. The purpose of this discussion is to introduce students to HDL, LDL and hypercholesterolemia (respectively, the good, the bad, and the ugly).

Activity:

There are two ways to approach this activity:

(1) Have students record their nutritional information for one entire meal. They should record what they ate, how much, and the nutrition information from the labels on the packages. It is important to remind them to include everything. For example, if they had a sandwich they would need to record bread, mayonnaise, mustard, lettuce, tomatoes, pickles, and turkey. Students like this option because they have autonomy, and it is individual; however, it will still be necessary to prepare for the second way in the event that students forget. Have the students calculate the number of calories, grams of fat, grams of carbohydrates, grams of protein, milligrams of sodium, and milligrams of cholesterol consumed for one of their meals.

(2) Plan a regular meal. Have copies of the nutrition information for each food item. Have the students calculate the number of calories, grams of fat, grams of carbohydrates, grams of protein, milligrams of sodium, and milligrams of cholesterol consumed.

This is an ideal opportunity to teach your students about nutrition labels, daily value percents, and the USDA food guide pyramid. You may find many of your students have misconceptions about nutrition and healthy living. Once they seem ready to move on to more detailed aspects of nutrition you can begin a discussion about cholesterol. Ask the class what they know or have heard about cholesterol. They should generate a wide range of facts or ideas. Use their ideas as building blocks as you try to get across a few main ideas:

(1) Cholesterol is an important constituent of cell membranes and the precursor of steroid hormones and bile acids. We could not live without cholesterol.

(2) High cholesterol levels are implicated in both heart attacks and strokes (leading killers in the United States).

(3) There are two kinds of cholesterol-- the good and the bad. The good cholesterol is called HDL (high density lipoprotein). HDLs remove LDLs from the walls of arteries. The higher HDL level the better. The bad cholesterol is called LDL (low density lipoprotein). LDL molecules deposit themselves on arterial walls and cause blocked arteries.

(4) You need some cholesterol in your diet, but about two-thirds of the total needed cholesterol is manufactured in the liver from other chemicals.

The danger with cholesterol is having high levels of LDLs in your body. This condition is known as hypercholesterolemia and can be caused by poor diet, lack of exercise, smoking, and/or genetics. Familial hypercholesterolemia is the most common inherited disease. About 1 in 500 people is heterozygous for this autosomal dominant trait. Such people are genetically predisposed to having high levels of LDLs. "Hypercholesterolemia is a silent disease. No symptoms will occur until the resulting chest pain of a heart attack or the symptoms of a stroke."* Divide students into groups to discuss ways to prevent building up of LDLs to decrease the chance of heart disease and stroke.

Here are some important ideas that can be discussed as groups present their ideas.

(1) Cholesterol levels can be controlled through changes in lifestyle (diet, exercise, quitting smoking) and through prescription drugs.

(2) If persons have a family history of high cholesterol, one's doctor can determine cholesterol levels and advise what to do.

(3) Individuals with familial hypercholesterolemia can generally be diagnosed during infancy. Heterozygous individuals generally have cholesterol levels 3 to 5 times higher than normal. Individuals who are homozygous (a much rarer condition-- 1 in a million) have cholesterol levels 7 to 12 times higher than normal. These individuals usually do not survive past their teens. Teachers must be especially sensitive when discussing this lowered life expectancy.

(4) However common familial hypercholesterolemia is, "it is generally believed that the typical high fat, high cholesterol, high protein, low fiber U.S. diet is largely responsible for the unfortunate statistic of 600,000 deaths annually."* This shows how significant our lifestyle is in allowing us to live healthy.

After students have analyzed the meal provided for them, or their own food consumption diary, they should be encouraged to improve their diet and/or exercise in some way.

*Quotes taken from Familial Hypercholesterolemia

For more information visit Online Mendelian Inheritance in Man

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