Surprisingly, drinking carbonated water is anything but new. Since 1767 we've been guzzling the stuff, but why? What explains the popularity of something so flavorless?
The short answer, of course, is sensation. We aren't exactly sure what causes this feeling in our mouths: you might assume that it's the bubbles popping on your tongue, but when people drink carbonated beverages in a pressure chamber (where bubbles don't burst) the sensation remains the same.
The Chemistry
So let's get into the details. Combining water and CO2 creates carbonic acid, which is picked up by taste beds that sense sourness. Carbonic acid has a certain enzyme called carbonic anhydrase which sits on those taste buds and reacts with the acid, causing carbonation's popular popping sensation. The enzyme, combined with a reaction in the body's trigeminal nerves, actually activates our pain receptors.
So, on paper at least, we should really hate drinking carbonated water.
Infatuation with Carbonation
But it's not that simple. Another study showed that an increased concentration of carbon dioxide in beverages can lead to a perceived sense of coolness. Actually decreasing the temperature of carbonated water, on the other hand, increases irritation. This provides evidence of some link between carbonated water's enjoyable "bite" and a pleasant cooling sensation.
Other animals do not share our infatuation with carbonation. Mice, according to Nicholas Ryba, a senior investigator at the National Institute of Dental and Craniofacial Research, will not drink it. Neither will horses and other animals. A lot of ugly stuff in nature emits CO2, like rotting flesh, so it makes sense that animals would be naturally averse.
But, although we aren't like our wild animal brethren in their aversion to CO2, there isn't any evidence to suggest that it's bad for us. If that's how you like to hydrate, keep it up! After all, it's better than not drinking water at all.