cr and lowering cholesterol

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CHOLESTEROL ABSORPTION FROM FOOD

Gabe Mirkin, M.D.

Having high blood levels of cholesterol increaes your chances of

getting a heart attack. You raise cholesterol by eating too much fat,

saturated fat, partially hydrogenated fat, cholesterol and calories.

But your blood cholesterol level is influenced far more by how many

calories, and saturated and partially hydrogenated fat you eat than

by how much cholesterol is in the food you eat.

Cholesterol is found only in foods from animals, such as meat, fish,

chicken, dairy products and eggs. It is not found in plants. More

than 80 percent of the cholesterol in your body is made by your

liver. Less than 20 percent comes from the food that you eat. When

you take in more cholesterol, your liver makes less. On the other

hand, your liver makes cholesterol from saturated fats. When you eat

meat, chicken, and whole-milk dairy products, the saturated fat is

broken down by your liver into acetone units. If you are not taking

in too many calories, your liver uses the acetone units for energy,

but if you are taking in more calories than your body needs, your

liver uses these same acetone units to manufacture cholesterol. That

explains why taking in two eggs a day does not raise blood

cholesterol levels in the average American. They are already taking

in so much cholesterol from meat, fish and chicken and diary

products, that when they take in more, they absorb less.

An article in the Journal of Lipid Research shows that the average

American takes in 350 mg per day of cholesterol. If he takes in 26 mg

per day, he absorbs 41 percent. When he takes in 188 mg cholesterol

per day, he absorbs only 36 percent, and when he takes in 421 mg per

day (the equivalent of two eggs), he absorbs only 25 percent. Some

people absorb more than 5 times as much as other people at the same

intake. So you lower blood cholesterol levels far more effectively by

eating less food, saturated fat and partially hydrogenated fats than

you can be restricting meat, fish and chicken for their cholesterol

content.

August 1999 The Journal of Lipid Research