Why Does V8 Cure Hangovers?

From the website:

One of our readers (okay, it was my friend Lisa) noticed a mention of “National Hangover Day” in our new-holiday contest — a day of bleary-eyed and queasy celebration on which “V8 will be vastly discounted.” Lisa wanted to know why V8 juice and other tomato products seem to cure hangovers — and, as an ardent subscriber to that theory, I did too! It seems the theory hasn’t been fully tested by science, but there are several reasons a big glass of the red stuff might help on a rough morning …

Mental_floss has got the answer: Link