Cholesterol is a critically important compound in the human body. It is synthesized in the liver and then used in the manufacture of bile, hormones, and nerve tissue. But cholesterol is also a part of the human diet. Humans tend to eat different things that add to cholesterol already produced by the body.
The human body contains a feedback mechanism that keeps the serum concentration of cholesterol approximately constant. The liver itself manufactures about 600 mg of cholesterol a day, but that output changes depending on....

.....the intake of cholesterol in the daily diet. As a person consumes more cholesterol, the liver reduces it production of the compound ,If one's intake of cholesterol greatly exceeds the body's needs, excess cholesterol may then precipitate out of blood and be deposited on arterial linings.
It is not that cholesterol is bad. Cholesterol is used for vital processes in body. A balance of Low density and high density cholesterol is good. But if high density cholesterol increases then the Low density cholesterol is unable to move the high density cholesterol out of the blood stream and therefore the high density cholesterol settle in the blood stream.

For this reason we need diets that can increase our LDL and we need to eat the following to make that happen.

In order to reduce HDL settling down in arteries:

• Lose excess pounds
• Get some daily exercise
• Quit smoking
• Drink alcohol only in moderation
• Take Vitamin E.
• Vitamin C and Vitamin B-6

In order to increase LDL so that LDL can remove excess HDL out of bloodstream:

• Fish and omega-3 fatty acids
• Oatmeal and oat bran
• Walnuts, almonds and more
• Eat heart-healthy foods
• Calcium brewer’s yeast
• Cucumber
• Watermelon
• Avocados
• Canola oil
• Cereal
• Grapeseed oil
• Ground nut oil
• Oatmeal
• Olive oil
• Peanut oil and other nuts
• Popcorn
• Safflower oil
• Sesame oil
• Sunflower oil
• Whole grain wheat
• Fruits and Vegetables reduce cholesterol because they don't contain any cholesterol -- cholesterol is only present in animals.