Why are diet fizzy drinks bad for you?

morrighu i already knew somewhat about all you stated but your writing skills reminded me why i should stop..starting NOW! ..no more coke zero here..heh thanks

Original Post by morrighu:

Potassium Benzoate - In combination with Vitamin C, it can form Benzene, a known carcinogen.  It's also described as "mildly irritant to the skin, eyes and mucous membranes".  When you drink it, it's in contact with the "mucous membranes" in your digestive tract. 

 I'm not questioning any of your other points (though it's worth noting that the stomach is more acidic to start with than anything in coke),  but this one's wrong.  Vitamin C's not nearly a strong enough reducing agent to turn any benzoate into benzene - and potassium benzoate is relatively unreactive and certainly not able to convert Vitamin C into benzene.  I suspect the "mildly irritant to the skin, eyes and mucous membranes" was cited from an MSDS which means that it applies to potassium benzoate as a solid not when in solution.  Sand, salt and most other solids get similar notes. 

Please note that I'm not saying potassium benzoate is good for you, but it can't do what your sources are claiming.