Some researchers compared the composition changes of 10 vegetable oil after four kinds of "Chinese cooking"-cold salad, frying, frying and frying [1]. It was found that the content of monounsaturated fatty acids in olive oil was still high, and the fatty acid composition was the least damaged.
Some researchers fried French fries with five different brands of olive oil [2]. After frying for 24~27 hours, the content of polar compounds in the oil was only 25% (the safety standard stipulated by most countries).
In other words, although there are losses, the antioxidant capacity of olive oil is better. So it can be used for cooking; But like all other edible oils, the oil temperature should not be too high and the cooking time should not be too long.
Usually we blow things up at home. There are not many fried things, the oil is hot for a short time, and the degree of oil oxidation is not high. In this way, the fried oil can be used for cooking immediately (filtering out impurities); Next time, use new oil.
If you need to fry food repeatedly, you can use peanut oil or other oil with high saturation.