Which oil should I cook with?
…and which one is the “best” for frying?
When it comes to frying*, there is no oil that is best to use — nutritionally, frying is not a legit cooking method!
The criteria that determine which oil is best to use for cooking is represented by its smoke point (that is the temperature at which the fats found in the oil start to break down, creating toxic and cancerous substances).
When the oil starts to smoke, that is a visible sign that it is getting damaged and you should turn down the heat.
Make sure to never reuse the oil you have heated once already.
When oil is heated to a high temperature (e.g. while cooking, if left in the sunlight, or if reheated) it gives life to free radicals, marauding cells that ransack your body, speeding up the ageing process and leading to disease.
As a rule of thumb, the more polyunsaturated fatty acids the oil contains, the less appropriate it will be for cooking (hence, for frying).
Polyunsaturated fats are very unstable and susceptible to rancidity when exposed to oxygen and are harmful when heated.
Most seed oils are high in polyunsaturated fats — PUFAs (e.g. sunflower, canola/rapeseed, flaxseed oils) and they are therefore NOT ideal for cooking with heat, let alone for frying. Although rapeseed oil can be considered mainly as monounsaturated fat, the chemical extraction methods used cause its polyunsaturated fats to oxidise (and that is not good).
PUFAs’ chemical bonds break easily, causing free radicals to run riot in a very short amount of time. Their smoke point will also be usually very low.
Another thing: many vitamins and minerals are lost by exposure to excess heat, and fatty acids oxidise. When overheating oils, you create toxic compounds (such as acrolein or acrylamide, to name a couple.)
Moreover, remember that every oil carries the same energy value: ca. 9kcal for every gram of oil — it does not matter which oil you are using!
Therefore, there is no such thing as a “lighter” oil to use (when frying, for instance) — it is just a matter of taste.
Drumroll, please…
The best oil to cook (and possibly fry as well, at low heat) with is most definitely extra virgin olive oil.
It is a monounsaturated fat and has a lower chance to create free-radical damage.
When buying this, pay attention to the label: where does the oil come from? It should state that the oil was extracted by mechanical means only (and not chemical ones), and the ingredients should not comprehend “a mix of olive oils from different countries” nor “refined oils”. If it’s cheap, it’s very likely that you are not buying authentic, pure extra virgin olive oil.
If you are intrigued, and fancy trying something new, consider safer cooking methods, such as steaming and baking (being mindful of not turning on the oven just for a small tray of food. We love being environment-friendly too. :) ).
Make sure you always read the labels of the products you buy and be wary of the ingredients you don’t recognise/are difficult to read.
*Side note: by “frying”, I mean adding plenty of oil in the pan, allowing the food to float in it. If you fry in a tiny amount of oil, the type of oil you are going to use will not make a difference: the heat will indiscriminately damage it, leading to free radicals breaking free.
