Don't get me wrong, I agree with all of the above - it's hard to beat flavour-wise and equally it's hard to beat in its raw state, so it's perfect for dipping bread, making salad dressings or even drizzling over your favourite [already cooked] pasta or a rack of lamb for example. Particularly extra virgin olive oil has one of the highest concentrations of monounsaturated fat, which actually reduce cholesterol and help to maintain joint, heart and brain function.
However, the key thing to note about oils is their "smoke" or "burn point", which causes these fantastic beneficial compounds such as monounsaturated fats and antioxidants to degrade and break down. Also to note - the oil is burning, so it is creating smoke containing carcinogenic toxins and other harmful compounds. So what are the "burn points" of various fats?
- Extra virgin olive oil - 160 degrees Celcius
- Butter - 177 degrees Celcius
- Virgin olive oil - 190 degrees Celcius
- Sesame oil - 210 degrees Celcius
- Rapeseed oil - 238 degrees Celcius
- Sunflower oil - 246 degrees Celcius
You will have noticed that I included butter. Burnt butter [beurre noisette] is a prized element of classical French cooking, which gives me a good opener to mention that things won't harm you in moderation. It's when we cook with them incorrectly all of the time that they become a problem. Water, our staple of life, is toxic to us in large quantities. I saw a chef once fry something in butter and extra virgin olive oil. When asking him why, he quite rightly replied that he wanted to have the taste the butter but didn't want it to burn, so the oil would increase its burning point. It's a common technique, but not with olive oil please...
There is a grey area - slow cooking with olive oil, sub 160 degrees. In my mind this is fine and I do it on occasion. It is important to note that the heating of the oil will still degrade the monounsaturated fats and antioxidants, but we don't get any of the carcinogenic toxins or other nasties resulting from burning the oil. For something like roasted Mediterranean vegetables, you can't beat drizzling them with a bit of olive oil and balsamic, but cook them low and slow.
So what's the alternative? Well the best news is that it's local, it's British and it's delicious - rapeseed oil. It has a n earthy, grassy quality to it when fried, which gives food a lovely moreish flavour. It's the oil of choice in many top restaurants around the country, with good reason. Rich in the prized Omega 3, 6 and 9 oils (usually obtained as a supplement from that horrific stuff cod liver oil), it also contains lots of monounsaturated fats and Vitamin E, which is a great natural antioxidant.
We hear this "antioxidant" word a lot and know that it's good for us, but what exactly is it? In simple terms, it is a particle that gets rid of toxins. More technically, it reduces thenfree radicals (toxins) in our body by inhibiting oxidation of that radical with another molecule, turning it into something that isn't harmful. In the case of rapeseed oil, for example, let's say we're serving it as part of a salad full of Vitamin C. The antioxidants from the Vitamin E in the rapeseed, persuade the Vitamin C to give up a hydrogen molecule, which binds to the toxin.
So just to be clear - I don't hate olive oil, I love the stuff. I just hate seeing it misused. By cooking with olive oil (and particularly extra virgin olive oil), we're not only destroying what we love it for - the aroma and the flavour - but we are actually reversing the beneficial properties that it gives us in its raw state. It's madness.