I discovered this about a year ago and I spent a lot of time researching the issue.
I got interested in it after learning that Canola Oil is all deodorized. Then I discovered most olive oil is. And most vegetable oils.
I noticed that good quality olive oils have a wonderful odor, as does coconut oil (which can also be deodorized if you buy the wrong brand), and that is what I seek out now. I spend a fair amount of dough at a fancy olive oil store on good quality olive oil.
I wish a food scientist would answer whether my hunch that fouled oil is really bad for us is true; in the meantime, it sure does taste better than the kind with all the flavor taken out.