[SauronOfMordor]

All I know is that I seem to have an alergic reaction to it. If I consume something with asperteme for a while, I develop a persistent cough, which goes away when I take it out of my diet. I experimented with this for two cycles (take it, develop cough, discontinue, cough goes away) to confirm

[Petronski]

I think "allergic reaction" is an excellent description of the phenomenon. Some people have severe problems, others have minor issues (like me), and many people can drink it without any issues at all (except maybe the aftertaste).