Natural sparkling water seems much less aggressive for teeth than a sugary soda.
A small study presented at the NUTRITION 2026 conference shows that it briefly increases mouth acidity, without reaching the threshold generally associated with enamel dissolution. These results remain preliminary, however.
Enamel is the mineral layer that protects the surface of the teeth. It can begin to demineralize when oral pH drops below about 5.5. The stronger and longer this drop, the higher the risk of erosion, especially when acid exposures are repeated throughout the day.
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The researchers compared four drinks in 20 adults: still water, natural sparkling water, calcium-enriched sparkling water and a sugary soda. They measured the pH of saliva before consumption, then at several times after each drink, to observe how long the acidification lasted.
The soda caused the most marked and longest-lasting drop. The sparkling water also temporarily reduced pH, because dissolved carbon dioxide forms a little carbonic acid. However, saliva quickly brought acidity back to its initial level, without dropping below the 5.5 threshold in this experiment.
This does not mean that all sparkling waters are equal. Flavored versions may contain citric acid, juices or other ingredients that are more aggressive for enamel. Sugar adds a second mechanism: oral bacteria transform it into acids, which further prolongs the teeth's exposure.
The added calcium did not radically change the observed results. This avenue nevertheless remains interesting, because calcium contributes to the mineral balance of enamel. The study did not directly measure tooth material loss. It only tracked saliva acidity, which is an indirect indicator of risk.
The limited number of participants also prevents generalizing these results to the whole population. The amount and composition of saliva vary from person to person. Oral hygiene, diet, frequency of consumption and fluoride use also affect the mouth's ability to neutralize acids.
For common use, natural sparkling water consumed in moderation therefore appears less concerning than a soda. The risk increases especially when an acidic drink is sipped over several hours. Longer studies will need to verify whether this brief acidification actually produces measurable effects on enamel.