I have always been a firm believer that as canola oil is a frankenfood, it should certainly be avoided. The heat involved in the processing of the oil is usually blamed for the unhealthfulness of the end product - omega 3 fats are rancid, etc.
However, a colleague of mine is claiming that it is scientifically possible to extract the oil from rapeseed without hydrolyzation etc, resulting in a healthful end product. The next stage of damage is usually during deoderisation through heating, but I can't find any expeller pressed oils that don't seem to be deoderised.
Try as I might, I cannot find anything reputable online to support this. Fallon & Enig's The Great Con-ola is wonderful, as are many other resources, but they don't seem to rule out the scenario that my colleague suggests. While I can't imagine a way to removing erucic acids, refining and deoderising the oil, in an effort to make it palatable, maybe it has been done...
His wife is vegan, and uses margarine as her source of omega-3. With cold-pressed canola, this seems technically possible; however, I see no evidence of any research in this area (but I don't subscribe to many study websites).
I'm curious about this mainly because I have a relative who is utterly fat-phobic, thanks to his high school education teaching him that animal fats are bad (blah, blah). If he's going to use margarine, I'd like to find the least damaging option for him, if such an item exists.
Edit 4th August - from the lack of evidence, I'm left with a pretty strong sense that VERY few producers, if any, are making canola oil and products without risking the integrity of the fats via heating for various purposes. So canola will remain on my blacklist, and my respect for my colleague forever tarnished ;)