Have you been joining the legions of people since the 1980s following Florence Henderson and her pitch for the perfect, healthy, vegetable oil? Don’t you just love “vegetable oil”? Which vegetable would that be? I mean, there are only literally hundreds of potential vegetables that you can choose to make oils from. Why, there is corn oil (which we obviously know isn’t going to be on the list anyway due to it being corn based). There are plenty of other options though, from rapeseed oil, I mean canola oil, to soybean oil ot god knows what else. While people before the industrial revolution cooked with oils all the time, they often were using oils like olive oil or oils from larger seed-based plants. It wasn’t until the dawn of the industrial revolution that many of these oils became widely available.
Oils like olive oil and coconut oil come from grinding and pressing them. The creation of oils like rapeseed oil, now given the more palatable marketing name of canola oil, starts in a similar process but just on a grander scale. While in the particular case of rapeseed it had been used as a fuel for lamps for millennia it wasn’t until the industrial revolution that humans figured out how to make it consumable. First by steam cracking the seeds and then by washing it with hexane (doesn’t it sound delicious when you put it like that) we can get to the oil in massive quantities in ways that couldn’t be done before. Actually much of the vegetable oil we eat is processed in a similar sort of heating then chemical washing way. It’s supposedly pretty safe, considering we’ve done it for a century or two but it certainly doesn’t have the millenia long history that other oils do in our diet.
All of that aside the bigger problem with vegetable oils over stuff like cold pressed extra virgin olive oil is the fat profile of what we are eating. While oils like olive oil have a much higher composition of fats from monounsaturated fats, oils like corn, soy and canola oil are weighted more heavily towards polyunsaturate fats. There is also the question of how much degradation of the fat structure is induced by the extreme heats used in the processing of these oils. There is also the question of additional nutrients that one would find in more traditional oils than what would be found in vegetable oils.
With the ready availability of extra virgin olive oil, coconut oil and other more tried and true fat products, it’s hard to find a convincing argument for regularly using vegetable oil for cooking. In the case of its use over lard or coconut oil there is the whole question of if saturated fat found in those products is bad for us or not. There is more debate on that topic than some would have us believe. In the case of flavor, there are times when one is looking for a flavorless oil compound to cook with. For those rare occasions perhaps one could try these products. I’m more willing to buy some of the rhetoric on vegetable oils not because I think they have totally sealed the deal with empirical data but because as a component of human diets they are an extremely recent phenomena.