I just watched it. This is not a rebuttal of Lustig. If Kern is attemping to rebut Lustig, he has failed pretty hard. He agrees with Lustig on several major points:
- Fructose is harmful at high levels
- Sucrose and HFCS are basically the same metabolically
- There are not major differences between refined and unrefined sugars
Remember, Lustig has two major conditions on which fructose can be a toxin:
- A large dose. He calls it a dose-dependent liver toxin, which it clearly is. I think Lustig's estimate is > 50g/day (Kern did not seem to disagree with this sentiment).
- The person consuming it is not an endurance athlete who can utilize fructose before it overwhelms the liver.
Let me summarize the talk. Kern repeats a strawman over and over (fructose is a poison). Then he shows a whole bunch showing that fructose is a poison at high levels. Umm... ok. Then the really hilarious part is he shows studies at near common levels of consumption and there are STILL negative effects, which he tries to hand wave.
Finally, he shows that if you feed people the same amount of fructose they typically eat, then their markers of health don't change. Huh? What else would you expect?
If you're looking for a reason to actually watch the video, near the end there is an intriguing part about the difference between honey and sucrose.