Olive oil breaks down easier when heated than butter or beef fat because it has more fragile fats in it.

Olive oil’s polyunsaturated fat content (11%) renders it more susceptible to thermal oxidation than animal fats with lower PUFA content (e.g., tallow, ghee <2%).

Extra virgin olive oil produces higher levels of polar compounds and oxidative byproducts than saturated animal fats and coconut oil when subjected to prolonged heating.

When you heat olive oil really hot, the healthy unsaturated fats break down much faster than the saturated ones—oils with more unsaturated fats lose them the most, making the oil less healthy.

When you heat olive oil, it makes more of two harmful chemicals — HNE and ONE — than the other oils tested, likely because it’s high in oleic acid.

Avocado oil contains 13–15% polyunsaturated fatty acids, rendering it susceptible to thermal oxidation despite a high monounsaturated fat content.