Do searches for 'fructose' and 'sucrose' and you'll get more info on why HFCS is problematic.
Basically, sucrose (regular table sugar) is not a trigger but fructose is in large amounts - which includes high fructose corn syrup, fruit juices and for some people large amounts of honey too. Fruit seems to be ok though since there is not a large amount of fructose in just whole fruit.