If you cook with polyunsaturated oils, such as soybean, canola, corn and sunflower, there's something you should know. A recent study at the University of Minnesota reveals that, when these cooking oils reach too high a temperature (365 degrees or more), are heated for half an hour or more or are later reused, HNE (4-hydroxy-trans-2-nonenal) forms and is absorbed into the food. HNE is a toxic compound that interacts with DNA, RNA and other biomolecules, putting the body at higher risk of cardiovascular disease, stroke, Parkinson's, Alzheimer's, Huntington's disease ... even cancer.

So, if you must fry that chicken, make sure the oil does not get hot enough to smoke and dispose of the oil when you have finished cooking. Do not reuse it. When dining out, reconsider fried foods if you think the kitchen may be recycling cooking oil.