Small amounts of naturally occuring fructose such as is found in fruit an vegetables is OK, but adding refined fructose to your diet isn't - regardless of whether it comes from a natural source. Fructose does more damage in your body than glucose, because it is absorbed into the tissues without the need for insulin (which is good) but it is much more likely than glucose to attach to and damage proteins (which is bad) and the damage glucose does is largely to the red blood cells which are replaced every 3 months or so (hence the significance of a glycated haemoglobin test - A1c) whereas fructose having been absorbed from the bloodstream is more likely to damage more important tissues and organs (which is very bad!)

Cheers,

Malcolm