Unsweetened sparkling water might be a better choice for your teeth than sugary soda. This is according to a new study that looked at how different drinks change the acidity in your mouth.
The study found that soda caused the biggest and longest drop in mouth acidity. Sparkling water also lowered acidity, but only for a short time. Then, saliva brought the acidity back to normal. Importantly, the acidity from sparkling water stayed above the level that can damage tooth enamel.
How Drinks Affect Your Mouth's Acidity
Tooth enamel starts to wear away when the mouth's pH level drops below about 5.5. Researchers wanted to see how sparkling water compared to soda and plain water.
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Start Your News DetoxThey tested sugar-sweetened soda, regular sparkling water, calcium-fortified sparkling water, and plain water. Twenty adults participated, and each person drank every beverage. This helped the team see how each person's mouth reacted to each drink.
The scientists measured the pH of saliva, not just the drinks themselves. This showed how the mouth responded right after drinking.
Wajiha Zulfiqar, a graduate student at Purdue University, explained that this method gave a more realistic view of how drinks affect oral health. She presented these findings at NUTRITION 2026, a meeting of the American Society for Nutrition.
Soda vs. Sparkling Water
Soda caused the largest increase in mouth acidity. Saliva pH was much lower after drinking soda compared to water, both at two and 20 minutes later.
Regular unsweetened sparkling water caused a temporary drop in pH after two minutes. Calcium-fortified sparkling water caused a drop after five minutes. For both types of sparkling water, the pH returned to normal within 20 minutes.
Saliva helped bring the acidity back to normal after both soda and sparkling water. The pH stayed above the level that damages enamel in the short term.
The researchers noted that this study only looked at short-term changes in pH. How often someone drinks a beverage, how long it stays in contact with teeth, and if it contains sugar also affect dental erosion.
A Safer Choice for Your Teeth
"Our results suggest that replacing sugar-sweetened sodas with unsweetened sparkling water may help lower the risk of enamel erosion," Zulfiqar said. She also mentioned that beverage companies could look for ways to make acidic drinks less harmful.
The team plans to study the long-term effects of sparkling water on oral health next. They want to see if it changes other factors that contribute to healthy teeth and gums.
Zulfiqar sparkling water abstract - American Society for Nutrition, 2026
