Soda -> Stupid in da head

Today I commented that 'Well, wasn't that unnecessary?' to one of the ~10 year old kids in the park that just kicked on his empty soda bottle so that it broke against a bench. 'Yea, wasn't it?' one of his compadres replied. He started to pick the pieces up and I left them sitting there, probably thinking I was stupid and what not. Minutes later they were all gone and I noticed that the broken bottle was still on the ground, together with one other and a soda can that was twisted so that sharp pieces of metal protruded from it.
The only explanation I can come up with is that soda makes you fucking stupid in the head. There should really be an age limit for buying that shit, or maybe it should be banned all together.