Within an hour of consuming it, the drink can raise ketone levels to a level similar to what you would see after at least seven days of fasting

I don't know, the most extended hypothesis seems to enunciate that the main responsible was the olive oil. C60 form adducts with the polyphenols in the olive oil, allowing them to enter the cell; but, if the olive oil has been spoiled by air, light... this adducts are going to be harmful.