It now appears that fructose triggers the up-regulation (increased expression) of both fed and fasted state genes. Many more than the researchers were expecting to see increase.
Normally when you consume most types of carbohydrates the body is able to break them down and either burn them off or store them as glycogen.
When the body encounters fructose however it seems to get somewhat confused and triggers genes that are involved with both liver glycogen storage (normal way to store glucose in the fed state) as well as genes that lead to increased triglyceride storage in the liver. Not a good thing, considering that a fatty liver is one of the components of the metabolic syndrome.
Now, don't go out and think that you have to avoid eating fruit because it has fructose in it. Yes, fruit does have some fructose but it is very minimal. Don't forget, fruits are rich in fibre, vitamins and many different antioxidants. Stay away from the high-fructose corn syrup type stuff, no matter what these commercials may suggest:
Although I do like this one best:
What did you think of these ads?