Everyone knows that soda isn’t good for you, but is there something about the carbonation itself that is damaging? Some rumors have it that any kind of carbonated water can leach calcium from bones and erode tooth enamel. Is there any truth to these claims?
Carbonated beverages have been associated with lower bone mineral density and increased urine calcium excretion. However, carbonated drinks without caffeine do not increase calcium excretion. Moreover, caffeine’s effect on calcium and bone metabolism is negligible when sufficient calcium is consumed in the diet. Therefore the carbonated drinks that do impact bone mineral density are likely working through a mechanism other than carbonation or caffeine.
One suggestion is that the slightly acidic nature of carbonated drinks (usually due to citric acid or phosphoric acid) may increase bone resorption. However, this hypothesis has been tested and disproved.
Another study showed that a less acidic, alkaline mineral water with high sodium content did not impact bone metabolism. The same low acid, high salt mineral water was also shown to improve markers of heart disease.
What about tooth decay? Acidic foods and drinks are known to erode tooth enamel. Is the slightly lower pH of carbonated mineral water therefore something we should be concerned about?
In one study, artificially flavored sparkling waters were tested and shown to be very acidic and measurably dissolve a substance similar to tooth enamel (though the solutions were not tested directly on human teeth). Most were flavored with fruit juice (a known promoter of tooth decay) along with added citric acid, which explains the lower pH. While this is certainly a sign that flavored waters should be consumed with caution, other studies of carbonated water alone have shown a negligible effect on tooth erosion.
To summarize, while carbonated waters can be slightly acidic, there is no reason to suspect that they result in bone loss or promote tooth decay. However, sodas are linked to decreased bone mineral density and fractures, and both sodas and flavored sparkling waters can significantly promote tooth erosion.
When it comes to the science of wellness, distinguishing the facts from the urban legends can be tough. That’s why we’ve enlisted Darya Pino – a scientist, foodie, and self-proclaimed geek girl. Check out the ZocDoc Blog every other Tuesday to see her bust the biggest myths in health.
Image: Fizzy Water, a Creative Commons Attribution (2.0) image from Brandon curran.kelleher’s photostream.