While olive oil is considered the healthiest fat on earth, many people believe that it can’t be used in cooking. But Mediterranean people have been cooking with extra virgin olive oil for centuries and do not see any adverse effect.
So is that true or just a myth that olive oil isn’t good cooking oil? Is olive oil stable in heat?
To know whether we should cook with olive oil or not, let’s take a look at some characteristics of good cooking oil.
The stability of fats
There are three types of fatty acids: saturated, monounsaturated, and polyunsaturated. The difference between them is the number of double bonds in their structure. Saturated fats have no double bond, monounsaturated fats have one, and polyunsaturated fats have many double bonds as its name suggests.
The number of double bonds tells us about the stability of fats. Double bonds are unstable when they are exposed to a number of elements. These elements include light, heat, and oxygen, leading to what is called fat oxidation. So polyunsaturated fats are the most unstable since they have many double bonds. In contrast, saturated fats are extremely stable, and monounsaturated fats are highly resistant to oxidative damage.
When fats oxidize, they form unhealthy molecules called advanced lipid oxidation end products (ALEs). These ALEs cause an inflammatory reaction in the circulatory system, as well as the liver, kidney, lungs, and gut. These are thought to have negative impacts on human health.
The smoke point of oil or fat is the temperature at which, under specific and defined conditions, it begins to produce a continuous bluish smoke that becomes clearly visible. The oil that has a low smoke point is not suitable for many cooking methods such as deep-frying.
Heating the oil above its smoke point increases the likelihood of oxidative damage and the creation of potentially harmful compounds. The oil also has a bitter flavor when it is burnt. Therefore, it loses both nutritional value and taste.
Extra virgin olive oil in cooking
Extra virgin olive oil has three key elements that make it suitable for cooking: it contains mostly monounsaturated fats, has a smoke point that is suitable for various cooking methods, and has a high level of protective antioxidants.
Some other vegetable oil, like soybean oil with 60% polyunsaturated fats can cause fat oxidation. However, extra virgin olive oil is made up of mostly monounsaturated fats – the highly stable one with only one double bond. Therefore, fat oxidation is less likely to happen with this type of oil.
Contributing to the resistance to oxidative damage of extra virgin olive oil, polyphenols and tocopherols in the oil act as phenolic antioxidants. One study fried olive oil varieties to see how they stood up to high heat, and only after 24-27 hours of frying (depending on the type) were they considered to be harmful. The researchers also found that the polyphenol content of olive oil predicted its susceptibility to oxidation; varieties with more polyphenols were less prone to oxidation while those with less became more oxidized.
Besides, the smoke point of extra virgin oil is from 190-220°C. Sautéing on the stove equates to a temperature of around 120°C, deep-frying is usually in the range 160-180°C and roasting in the oven 180°C. So, as you can see, olive oil – especially the extra virgin one – is safe to use in popular cooking methods.
Why do people misunderstand olive cooking oil?
If extra virgin olive oil can be used to cook and many studies have proven that, why do people believe that olive oil is unstable and its smoking point is low?
In fact, this misconception is either true or false. High-quality, extra virgin oil has the characteristics of good cooking oil. But most olive oil is not high quality, non-extra virgin, which has a very low smoke point and a little beneficial substance. That’s why it’s important to choose the right olive cooking oil.
In conclusion, olive oil is a good cooking oil since it has stability in heat and is a suitable smoke point for regular cooking. You can and even should use olive oil in cooking. However, make sure that you’re using the high-quality, top-grade extra virgin type of oil.