Olive oil is not your best choice for cooking or frying because of its extremely low smoke point of about 350°F. This characteristic of olive oil means that the oil will burn more quickly than most other vegetable oils.
When olive oil is burned, the chemical structure of the oil itself is changed and loses most all of its healthful qualities and may even be mildly toxic. So if you’re going to cook with olive oil be especially careful not to overheat it for this reason.
Cooking with unrefined olive oil
Extra virgin olive oil actually burns more quickly than unfiltered or unrefined oil, so your best choice may be to use these less expensive types of olive oil for cooking. You can get away with using a lower quality oil because the flavor and texture of the oil is somewhat eroded by the heating process anyway.
When I cook with olive oil, which is usually for low heat sautéing of vegetables such as mushrooms, which is one of my favorites, I usually use a less expensive bottle of oil. The higher-quality bottles I save for eating raw such as drizzled on salads or dipped in breads.
Consider cooking with avocado oil
Keep in mind that when cooking with unrefined olive oil, you are not going to get the health benefits that come with the vitamins and nutrients that are in extra virgin olive oil, so it may be best to consider using another type of oil which is better suited to cooking.
Avocado oil, for instance, is a wonderful choice because of its high smoke point of 520°F, and also because it has wonderful health properties similar to olive oil. Avocado oil is harder to find but can be found at your local Whole Foods store, or ordered online.