Question:
Does anyone know the difference between glucose and fructose, and more to
the point, how these are treated by our system? I've heard some stuff about
fructose being transported to the liver, where it would be stored as fat,
whereas glucose is used for energy (transported to musclecells when suger
levels are low).
I always thought that ALL carbohydrates are converted to glucose, is that a
mistake?
Answer:
The majority of glucose (80% or so) passes through the liver without
processing, straight to the bloodstream where it can be used by various
tissues.
Fructose is processed mightily by the liver. Depending on the metabolic
state of the liver, it can be converted to glucose and then stored as
liver glycogen, converted to glucose and then released straight into the
bloodstream, or converted to triglycerides (this is typically only under
conditions of very high fructose intake, >50 g/day).
Contrary to various dogma out there (mainly from parillo),
small/moderate amounts of fructose are no big deal. It's only
non-physiologically high amounts of fructose (as you'd get from eating
foods high in high-fructose corn-syrup) which are a problem.
