It is a common belief that extra virgin olive oil should not be used for high heat cooking. I used to believe that too. Yet, at the same time I kept watching many celebrity chefs use extra virgin olive oil in their cooking. And it was high heat cooking.
Was I missing something? Was extra virgin olive oil really unsafe for high heat cooking? Let us do some fact check.
What Happens When Any Oil Is Heated
When a cooking oil is heated, it produces some by-products such as free fatty acids and free radicals. These in turn combine to create polar compounds such as monoglycerides, diglycerides and polymeric triglycerides. These polar compounds are not digestible and their regular consumption adversely impacts human health.
So, to what extent extra virgin olive oil degrades when heated compared to refined or chemically altered cooking oils?
The 2018 Study In Australia
A 2018 study – Evaluation of Chemical and Physical Changes in Different Commercial Oils During Heating – was carried out by De Alzaa F, Guillaume C and Ravetti L under the aegis of Modern Olives Laboratory Services, Australia.
“The aim of this study was to assess the correlation between an oil’s smoke point and other chemical characteristics associated with stability/safety when heating. Analysis was undertaken in an ISO17025 accredited laboratory.
Extra virgin olive oil (EVOO) and other common cooking oils were heated up to 240℃ and exposed to 180℃ for 6 hours, with samples assessed at various times, testing smoke point, oxidative stability, free fatty acids, polar compounds, fatty acid profiles and UV coefficients.”
This is what the study concluded about extra virgin olive oil:
“EVOO yielded low levels of polar compounds and oxidative by-products, in contrast to the high levels of by-products generated for oils such as canola oil. EVOO’s fatty acid profile and natural antioxidant content allowed the oil to remain stable when heated (unlike oils with high levels of poly-unsaturated fats (PUFAs) which degraded more readily).
This study reveals that, under the conditions used in the study, smoke point does not predict oil performance when heated. Oxidative stability and UV coefficients are better predictors when combined with total level of PUFAs. Of all the oils tested, EVOO was shown to be the oil that produced the lowest level of polar compounds after being heated closely followed by coconut oil.”
So, there it is. Extra virgin olive oil is the best even when heated.
If you want to read this complete study, click here (PDF, opens in new tab).