Is frying with extra virgin olive oil healthy

Extra olive virgin oil is touted for its health benefits. A staple of the Mediterranean Diet, the oil contains antioxidants attributed to its phenolic compounds.

While in Mediterranean countries extra virgin olive oil is regularly used as a final seasoning, it is also used for roasting, sautéing, stir-frying and deep-frying.

There is a risk that such culinary techniques could diminish the minor components of extra virgin olive oil, such as polyphenols. This could occur through substances leaching into the food, or by degradation and transformation of the oil’s polyphenol content.

A team of researchers from the University of Barcelona and the University of São ​Paulo have sought to determine whether, in a domestic kitchen environment, extra virgin olive oil is degraded when applied to heat – and specifically, when pan-fried or sautéed.

"The effects of cooking on these polyphenols of oil have always been studied in a laboratory or industrial situation, which is far from the reality of our homes,"​ noted director of the Institute in Research on Nutrition and Food Safety (INSA-UB) and study co-author Rosa M. Lamuela.

The thinking is that results from a domestic setting could be used to inform future recommendations or nutritional guidelines.

What is extra virgin olive oil?

Where regular olive oil is refined and stripped of important nutrients and antioxidants, extra virgin olive oil is produced using a natural extraction process – without the use of heat or chemicals.

This allows the oil to retain all the nutrients and antioxidants from the olive fruit. As a result, extra virgin olive oil is regarded the highest quality olive oil available.

Extra virgin olive oil is the main source of fat in a Mediterranean diet. It displays a singular fatty acid composition with a higher content of phenolic compounds and other antioxidants than other edible oils.

Its consumption has been demonstrated to play a protective role against diseases such as cancer, cardiovascular diseases, diabetes, and neurodegeneration.

Extra virgin olive oil in a domestic kitchen​

In the study, published in academic journal Antioxidants​, the researchers simulated the cooking conditions of a domestic kitchen. The aim was to determine how homemade sautéing affects the polyphenols of extra virgin olive oil.

The effects of time – whether the oil was sautéed for a long or short period – and temperature (at 120°C and 170°C) on the degradation of antioxidants was also analysed.

Is frying with extra virgin olive oil healthy
Image source: University of Barcelona

Results revealed that temperature did have a degrading effect on the polyphenols of extra virgin olive oil during the sauté cooking process. At 120°C, the content of polyphenols decreased by 40% and at 170°C, it decreased by 75% – compared to the levels of antioxidants in raw oil.

Time had an effect on such individual phenols, such as hydroxytyrosol, but not on the total phenol content.

Overall, antioxidant levels remained with the ‘healthy range’, as stated in European regulation.

"Despite the decrease in concentration of polyphenols during the cooking process, this oil has a polyphenol level that reaches the declaration of health in accordance to the European regulation, which means it has properties that protect oxidation of LDL cholesterol particles,"​ noted co-author Julián Lozano.

What do these findings mean for the Mediterranean diet?​

Is frying with extra virgin olive oil healthy
Olive oil is a key component of the Mediterranean diet ©GettyImages/aamulya

The Mediterranean diet varies from country and region but is largely based on consumption habits of those living in countries bordering the Mediterranean Sea, including Greece, Italy, Spain and France.

Broadly speaking, the diet champions vegetables, fruits, legumes, nuts, beans, cereals, grains, fish and unsaturated fats such as olive oil.

However, the health benefits experienced by those living near the Mediterranean and eating these locally sourced ingredients, are not always transposed to people following the diet in other geographies.

According to the researchers, this is likely due to cooking practices. These latest findings are expected to support the idea that Mediterranean cuisine is beneficial for health – not purely for the ingredients themselves, but for the ways of cooking it.

Thus, it would be beneficial to analyse the effects of cooking extra virgin olive other with other food elements from the Mediterranean diet. "Moreover, we should conduct random research studies in humans, in which we would compare the potential benefits we obtain when cooking with quality extra virgin olive oil compared to other oils," ​noted Lozano.

Source:​ Antioxidants​

‘Domestic Sautéing with EVOO: Change in the Phenolic Profile
Published 16 January 2020
DOI: https://doi.org/10.3390/antiox9010077​  
Authors: Julián Lozano-Castellón, Anna Vallverdú-Queralt, José Fernando Rinaldi de Alvarenga, Montserrat Illán, Xavier Torrado-Prat, and Rosa Maria Lamuela-Raventós

Is it OK to fry in extra virgin olive oil?

There are many vegetable oils that are used for deep frying food, including sunflower oil, peanut oil, coconut and even canola oil. Although opinions on which is the best oil for frying have always been very divided, extra virgin olive oil is one of the best oils for frying.

Why is frying with olive oil unhealthy?

Olive oil is no different from other oils. If you burn it (heat it above its smoke point) it will taste bad and it will contain harmful chemicals. Smoke points tend to increase with olive oil quality, as the free fatty acid content tends to decrease and the antioxidant content increases.

Is it healthy to cook with extra virgin olive oil?

Many people believe that it is not a good idea to cook with extra virgin olive oil. Several scientific studies have proven over the years that this myth is simply untrue. Not only is EVOO safe to cook with, but it is the most stable and safest cooking oil available.

Is olive oil deep frying healthy?

Olive oil and avocado oil are good choices for deep frying. Peanut and palm oils are less suitable, either for health or environmental reasons.