Drinking unsweetened sparkling water may not be as corrosive on teeth as sugar-sweetened soda, according to study findings presented on July 26 at Nutrition 2026 in National Harbor, MD. This echoes dietary recommendations to curb sugar-sweetened drinks.
Unsweetened sparkling waters may be a satisfying alternative to sodas if they are consumed in moderation.
“Many people are switching from soda to sparkling water, and our findings suggest that unsweetened sparkling water may be a lower-risk alternative to soda, when consumed in moderation and alongside good oral hygiene practices,” said lead author Wajiha Zulfiqar, a graduate student in nutrition science at Purdue University in Lafayette, IL.
Regular sodas -- with their high sugar content, carbonation, and other acids -- feed oral bacteria, which then weakens enamel over time, leading to tooth decay. Diet sodas, while sweetened with artificial sweeteners like aspartame and sucralose, pose a threat, too, due to the beverage’s acidity and carbonation. Both regular and diet sodas lower the mouth’s pH. When oral pH drops below 5.5, the acids in these beverages attack the enamel.
Researchers observed the in vitro pH dynamics of sugar-sweetened soda, unsweetened sparkling waters, including one brand fortified with calcium, and plain water in 20 adults ages 18 to 50. To reduce differences in the subjects that could skew the results, the same participants were assessed to compare in vivo changes in salivary pH during and after subjects consumed the three beverages.
After opening the beverages, pH measurements were taken at zero, two, five, 10, and 20 minutes. Using a randomized, within-subjects crossover design, participants completed four visits, during which they consumed a 12 oz. beverage over 10 minutes. Saliva samples were collected at baseline and two, five, 10, and 20 minutes post-consumption, and in vitro data were analyzed using ANOVA, while in vivo data were analyzed using a linear mixed-effects model that evaluated the beverage, time, and interaction, with pH as the outcome.
“Our results suggest that replacing sugar-sweetened sodas with unsweetened sparkling water may help lower the risk of enamel erosion,” said Zulfiqar. “The results also highlight an opportunity for the beverage industry to explore reformulation strategies that could potentially reduce the erosive potential of acidic beverages.”
Zulfiqar plans to conduct additional research, testing how sparkling water influences oral health long term, including if it initiates other changes in the mouth that maintain optimal oral health.
Read an abstract of Zulfiquar’s research.
