Polyunsaturated fats can be quite dangerous if they oxidize before consumption or after when the body does not have enough natural antioxidants to prevent same. The prime example of this is the oxidation of cholesterol in all our processed foods. Cholesterol is rapidly oxidized ot its 24,25 epoxide upon exposure of the food stuff to air, such can be greatly augmented by grinding, mixing, whipping, and scrambling. For the best nutrition and least problem from cholesterol-containing foods, the foods must have minimal exposure to air. This means a sof-boiled egg, poached egg, or even an over-soft to over-medium fried egg are all better than scrambled, omelete or souffle, Cooking with natural antioxidants can also help dramatically in preventing oxidation.