Oils are best alone on an empty stomach, when mixed with foods the liver will want to purge and purge and if the gallbladder is full of stones and or worms, same for the liver, then yes, your going to feel the burn of bile entering the lymph glands or getting into the blood and the heart is going to say NO.
Steps are needed to avoid all these things, Olive oil can support life, but only when consumed properly. You might be able to use oil all over your foods if your system was flowing correctly, but even then, I prefer on an empty stomach by its self.