Even though all the famous chefs on TV (mis)use it, it's important to know olive oil is too delicate to fry or heat. I heard Dr. Oz talk about it on Oprah a few years ago but a recent convo with a friend brought the memory to the front of my mind- a miracle these days! Anyway, according to him, its nutrients will break down and it will become a hydrogenated oil (very bad!) any time it is heated.
The way to test this out is to heat the oil, then cool it to room temp. If it stays liquid, it reached a safe (low) temp, but if it becomes solid, it is now a trans(hydrogenated) fat. These fats tend to accumulate in the body and have a hard time leaving, causing disease states eventually.
Sidebar: This is my own schooling and more bursts of memory kicking in here- a lot of pesticides are fat-soluble; if there are lots of trapped fats in the body, guess what else gets trapped there right along side them? Do the math. This is why, even on our tightest budget, I always buy organic-only dairy products like milk and butter, and organic, cage-free (ie stress-free chickens) eggs, because I shudder to think about consuming all the trapped/dissolved pesticides that the fats in the these products have when they are not organic.
So back to EVOO (Extra Virgin Olive Oil), you'll notice that it is sold usually in a dark glass bottle, to protect it from heat and sunlight. It is better to use grapeseed or peanut oil for high-temp cooking/frying and canola for the oven/medium-temp cooking. It's better to add olive oil to food following cooking while it is cooling or just before eating to preserve the benefits of it.
Because I don't like to put info out there without backing it up, I suggest you read up on snippets from the episode with more explanation and details here. Puh-lease ignore the comment at the end about High Fructose Corn Syrup. They try to make it seem harmless but it's not, end of story, and don't believe the hype.
Also, Dr. Oz's book "You: The Owner's Manual" might be worth checking out (free at the library!) for more info.
