"Unrefined polyunsaturated oils in small amounts can help provide us with some of the essential omega-6 fatty acids our bodies require. A better source for these essential fats would be vegetables, fruits, nuts, seeds, and grains. The public, however, is consuming way too many polyunsaturated oils like corn, safflower, sunflower, cottonseed, and soy. Too many of these fats can upset the balance they must keep with the omega-3 fatty acids, contributing to a number of problems including immune system dysfunction; damage to the liver, reproductive organs, and lungs; digestive disorders; depressed learning ability; impaired growth, and weight gain.
"Polyunsaturated oils are easily oxidized, making them a source of free radicals, which injure the arteries and create a situation that cholesterol tries to remedy. Not only does cholesterol attempt to repair the lesions created by free radical damage, it may be helping to prevent such damage in the first place by acting as a potent antioxidant."
"High intake of polyunsaturated oils weakens cellular membranes. When this occurs, cholessterol comes to the rescue. Additional cholesterol enters teh cell membrane in order to stabilize and restore proper cellular function. In the process, cholesterol is drawn from the bloodstream, thereby lowering serum levels temporarily." This is sometimes misinterpreted that polyunsaturated fats are heart healthy. "In fact, it appears that cholesterol is simply trying to repair the damage done by high levels of polyunsaturated oils. These fats were not common many decades ago when heart disease and certain other chronic diseases were rare." (taken from Politically Incorrect Nutrition by Michael Barbee, C.D.C., p 22)