Every nutrition article you have read about cooking with oils, will mention something called “smoking point”.
Many of these articles will also extoll the virtues of polyunsaturated fatty acids (PUFA), with some specifically talking about Omega 3 fatty acids and others about Omega 6 fatty acids as well.
How many talk about how most Indian families are poisoning themselves every day with oxidised PUFA?
The whole smoking point related “safe cooking” theory is a lie.
Smoking point is not relevant to toxic oxidised fatty acids. Most vegetable oils do not have to be heated upto their smoking points to become toxic. They become so at much lower temperatures.
Here is the real principle you must follow –
1. Never heat any Omega 3 rich oil. Example flaxseed oil or walnut oil. Never store it either. The Omega 3 components get oxidised at room temperature when exposed to air and light. That’s the reason why flaxseed oil (aka linseed oil) has never in history been used as an edible oil. That’s also the reason why it is sold in nitrogen flushed bottles.
2. Never use any vegetable oil (with the exception of coconut oil or palm kernel oil) for deep frying, tadka or any other open air high heat cooking practice. The vegetable oils are rich in Omega 6 fats and they start getting significantly oxidised at about 150 degrees centigrade, irrespective of the smoke point of the oil.
Oxidation of PUFA creates complex biproducts and toxic metabolites
These cause oxidative stress and can lead to diseases like cancer and more.
Please do not listen to your nutritionist recommendations on which oils are healthy to use as cooking oils, if they do not have a good understanding of heat induced PUFA oxidation and it’s toxicity.
Ignore smoke point. That’s not the real problem. Oxidation starts much earlier. At room temperature for Omega 3 fatty acids and at a temperature that’s much lower than the smoke point of almost any oil, for Omega 6 fatty acids.
And what are the safest cooking oils from this perspective? Ghee, coconut oil, lard and palm kernel oil. Use any of these for deep frying or tadka or any high heat cooking.
Here is one of those semi literate, misleading articles from so called nutritionists. Smoke point indeed! Poppycock : https://medium.com/mel-magazine/ranking-every-kind-of-cooking-oil-by-how-un-healthy-they-are-22bf5dadc3a5