Although many cooking oil manufacturers use the ‘high smoking point’ properties of their oil as selling points, this characteristic is not a very reliable indicator of when an oil is becoming damaged.
The smoke point refers to the point when an oil becomes rancid, due to the destruction of the fatty acid molecules in the oil. Unfortunately, most cooking oils are already severely damaged by the time they are bottled, so they are simply getting more damaged by the frying they undergo when they reach the frying pan.
Furthermore, manufacturers of cooking oils try to increase their oils smoking point by refining their oil, causing damage to the fat molecules in this process. But they cannot change the actual composition of the oil, which will tell you whether the oil will become damaged at low temperatures, or not.
The only way to tell whether an oil will become damaged when it is heated is to look at what kind of oil it is. Saturated fats, like butter and coconut oil, can withstand more heat than other fats, because of the their molecular structure. Monounsaturated oils, like olive oil, can handle light sauteing, but no extreme temperatures, while any polyunsaturated oil, like sunflower oil, or flax seed oil, should never be heated.
If an oil is a combination of different types of oils, as many oils are, then you need to know what the ratio is. For example, Grape seed oil, which has up to 70% Omega 6 polyunsaturated fatty acids, with the rest being monounsaturated, means that this oil should never be heated. The less polyunsaturated fats, the better for heating.
So, the smoking point does not refer to a health benefit. It is simply another selling point which confuses the unsuspecting consumer.
See the FAQ How To Use Fats And Oils In Cooking