Although there is evidence that the control of insulin through low glycemic indexed foods is on the right path, some feel it's too soon to call it the "cure". The Mayo Clinic Reports that, "the American Diabetes Association has concluded there isn't enough evidence to recommend the general use of a low-glycemic-index diet for people with diabetes." This is based on the fact that not enough testing has been therefore not all foods GI ratings are known and that combining foods may change there over all GI impact.
Even with this caution, I have still yet to find any published report of a negative effect of the low GI diet. So it may not yet be recognized over all, but it certainly seems to pose no known threats to good health.