I cannot recite the difference. I do remember that he asserts that there is a very big difference, something like fructose is metabolized more like ethanol, with the attendant harm.
He delves into organic chemistry in great detail. This is not my area of expertise but this guy is pretty darn convincing.
I do not wish to get into a fight here, I commented before realizing that it was pretty heated on this thread. But I have watched the video and was very surprised. I’d like your opinion after watching the presentation.
Anyway, Lustig is a well educated and eloquent man but he is very wrong in his assessment of fructose. Lustig likes saying that fructose is ethanol without the buzz. He also claims that they are both metabolized in the same manner. That's nonsense. Ethanol and fructose utilize completely different pathways. Alcohol converts to acid aldehyde and then into acetyl CoA. To do so, an enzyme called alcohol dehydrogenase is employed. This enzyme doesn't even figure in fructose metabolization. The metabolization of fructose and ethanol are not similar at all. Prolonged excessive consumption of ethanol can lead to liver fibrosis. Fructose consumption will not lead to this kind of organ damage.
Lustig claims that ethanol is a carbohydrate. It isn't. He also says that fructose is a toxin. It is not. The liver easily converts fructose to glucose. Of course, if you overwhelm the body with anything, bad things can happen.
In the video, Lustig says that fructose in fruit is fine because it has fiber. He believes that a fiber dosage per gram of sugar makes fructose from fruit just fine while fructose from sucrose is toxic. I believe he said the fiber inhibits the absorption of sugar. That sounds bizarre to me but who knows.
Finally, Lustig asserts that fructose increases subsequent food intake. He doesn't make clear why that is but I believe he thinks that sugar doesn't elicit satiation. If so, he's way off base here again.
I don't know why he says the things he does. He must have an agenda of some sort, but I have no idea what that agenda is. That's my two cents anyway. FWIW.