One thing to keep in mind about olive oil is that you should not fry foods in it. "If you take a healthy fat and you fry it—if it reaches its smoking point—then you actually are oxidizing it," Dr. Oz says. "When you oxidize it, you actually damage the fats, so you lose a lot of the benefit."
Rather than putting the oil in the pan and heating it, a better method is to put the food in the oil first and then add it to a heated pan. "That's a wonderful way of reducing the amount of oxidation that occurs," he says.