Purdue Study Finds Unsweetened Sparkling Water Gentler on Teeth Than Soda

Researchers at Purdue University evaluated how different beverages affect mouth acidity by measuring salivary pH in 20 adult volunteers. Participants drank plain water, sugar‑sweetened soda, regular unsweetened sparkling water, and calcium‑fortified sparkling water in separate sessions. The soda caused the greatest and most prolonged drop in pH, falling well below the enamel‑degrading threshold of 5.5. Both types of sparkling water also lowered pH briefly, but the decline was smaller and recovered faster, especially for the regular unsweetened version.

Graduate student Wajiha Zulfiqar said the findings suggest unsweetened sparkling water may be a lower‑risk alternative to soda when consumed in moderation and coupled with good oral hygiene. The results will be presented at NUTRITION 2026, the annual meeting of the American Society for Nutrition, held July 25‑28 in National Harbor, Maryland, USA.