Source: Nourishing Traditions by Sally Fallon

"Our blood vessels can become damaged through irritations by free radicals or viruses, or because they are structurally weak-this is when the body's natural healing substance, cholesterol steps in to repair the damage. Cholesterol in cell membranes give our cells necessary stiffness and stability. When the diet contains an excess of polyunsaturated fatty acids these replace saturated fatty acids in the cell membrane, so the cell walls actually become flabby.

Cholesterol is needed for proper function of serotonin receptors in the brain. Serotinin is the body's natural 'feel good' chemical. Low cholesterol levels have been linked to aggressive and violent behavior, depression and suicidal tendencies.

The cause of heart disease is not animal fats and cholesterol but rather a number of factors inherent in modern diets, including excessive consumption of vegetable oils and hydrogenated fats; excess consumption of refined carbohydrates in the form of sugar and white flour; mineral deficiencies, particularly low levels of protective magnesium and iodine; deficiencies of vitamins, particularly vitamin A, C and D needed for the integrity of the blood vessel walls and of antioxidants like selenium and vitamin E, which protect us from free radicals; and finally, the disappearance of antimicrobial fats from the food supply, namely, animal fats and tropical oils."