Short answer, yes. It is safe to cook with, and it’s suitable for most cooking styles except stir fry, because its smoke point is 210 degrees C.
Long answer:
There are 2 factors to consider:
Factor 1
The first one is purely practical. A smoke point is the temperature at which an oil with start to smoke. Extra Virgin Olive Oil has a lower smoke point (210 degrees C) than more refined oils, virgin avocado oil and virgin groundnut oil. You will struggle to stir fry with olive oil because it will burn on a high heat. But for shallow frying and roasting, Extra Virgin Olive Oil is a great option.
Factor 2
The second factor is the chemicals an oil breaks down into when it is heated. The heat causes oxidisation. ‘Studies have shown that consuming or even just inhaling these oxidative products can have some negative health effects and they have been linked to an increased risk of heart disease and cancer’ (Trust Me I’m A Doctor, BBC).
BBC’s ‘Trust Me I’m A Doctor’ tested different cooking oils in the kitchen to see what they broke down into. These are their findings:
‘We found that the oils which were rich in polyunsaturated fatty acids, like corn oil and sunflower oil, generated very high levels of oxidative products known as aldehydes. By contrast, the fats and oils which were rich in saturated fatty acids or monounsaturated fatty acids (like butter or olive oil) produced far fewer aldehydes and other potentially dangerous products.’
So, what oils should I be cooking with?
‘If you want to try and reduce aldehyde production, Martin suggests that you go for an oil or fat high in monounsaturated or saturated lipids (preferably greater than 60% for one or the other, and more than 80% for the two combined), and low in polyunsaturates (less than 20%). Olive oil is a good compromise because it is about 76% monounsaturates, 14% saturates and only 10% polyunsaturates.
Lastly, be careful with how you store your oil. Fats are susceptible to oxidation when they are exposed to light, heat and oxygen so try and keep your oils tightly sealed in a cool, dry cupboard.’
Rapeseed Oil is around 25% polyunsaturated fats, around 63% monounsaturated fat and around 7% saturated fat.
The diagram shows ‘The amount of toxic aldehydes found in our testing of oils with food (orange) and in the lab without food (yellow). The vegetable oil in our experiment was used multiple times in a deep fat fryer, which increases the amount of oxidation. Martin did not test groundnut oil under laboratory conditions so conclusions should not be drawn from our single apparently ‘negative’ sample from a volunteer – we do not know to what temperature it was heated.’
To read more about the experiment and the science behind this, visit
https://www.bbc.co.uk/programmes/articles/3t902pqt3C7nGN99hVRFc1y/which-oils-are-best-to-cook-with