cystalline fructose vs. HFCS

[kylecortez]

alot of new drinks now are being sweetened with crystalline fructose. vitamin water for example. fructose is reported to have a very low glycemic index (23 i think). i recall wai saying this is beacuse fructose has to be changed to glucose before it can raise blood sugar

why is that high fructose corn syrup has such a high glycemic index, and it is mostly fructose too? I can drink a vitamin water and have no glycemic reaction and if i drink a soda, i will get a headache and the shakes within minutes.

-Kyle

[RRM]

fructose is reported to have a very low glycemic index

Lower than glucose indeed, and yes, that is because its conversion into directly available energy goes a different (long) pathway.

why is that high fructose corn syrup has such a high glycemic index, and it is mostly fructose too?

Because its very much concentrated, but yet, if you compare it to a high sucrose or -glucose drink, the glycemic index is lower.