Zero sugar sparkling water is a fine alternative to sugary drinks and, for most people, a perfectly healthy choice. It hydrates just as well as still water, contains no calories, and avoids the sugar loads that make soda harmful. That said, the carbonation and added flavors do come with a few nuances worth understanding, especially around dental health, digestion, and appetite.
How It Compares to Still Water for Hydration
Sparkling water hydrates your body the same way flat water does. The carbonation is just dissolved carbon dioxide, which doesn’t interfere with how your body absorbs the fluid. If swapping still water for sparkling water helps you drink more throughout the day, that’s a net positive. The only real difference is the fizz.
The Dental Question: Acidity and Enamel
Dissolving carbon dioxide in water creates a weak acid called carbonic acid, which drops the pH slightly below neutral. For plain, unflavored sparkling water, the acidity is mild enough that it poses minimal risk to your tooth enamel. It’s nowhere near the erosive power of soda, fruit juice, or sports drinks.
Flavored varieties are a different story. Citrus-flavored sparkling waters often have higher acid levels, which does increase the risk of enamel damage. The American Dental Association recommends drinking citrus-flavored sparkling water in one sitting or with meals rather than sipping it throughout the day. Repeated, prolonged exposure is what causes problems, not the occasional can.
What “Natural Flavors” Actually Means
Most zero sugar sparkling waters list “natural flavors” as an ingredient. Under FDA rules, natural flavors are derived from plant or animal sources: essential oils, fruit extracts, spice distillates, or products of roasting and fermentation. The term is broad, and companies aren’t required to disclose the specific compounds used. In practice, flavored sparkling water typically contains tiny amounts of fruit-derived extracts. These aren’t harmful, but the label tells you very little about what’s actually in the can beyond carbonated water.
Effects on Digestion and Bloating
The carbon dioxide in sparkling water can cause temporary bloating, belching, and a feeling of fullness. In one study, participants who drank carbonated beverages reported significantly higher feelings of fullness and more frequent belching than those who drank still water, with the majority of belching happening within the first five minutes. For most people, this is mild and passes quickly.
If you deal with acid reflux or irritable bowel syndrome, carbonation may aggravate your symptoms. The temporary increase in stomach pressure from gas can push stomach contents upward. Research has found no significant change in actual stomach acid production from carbonation alone, so the issue is mechanical (gas expanding in your stomach) rather than chemical.
Carbonation and Appetite
One finding that surprises many people: carbonation itself may increase hunger. A study reported by UCLA Health found that both rats and humans who consumed carbonated water, whether sweetened or unsweetened, produced significantly more ghrelin, the hormone that signals your body it’s time to eat. The human participants who drank carbonated water had triple the blood levels of ghrelin compared to those who drank flat water or degassed sparkling water. The researchers concluded that the carbon dioxide itself, not sweeteners or flavors, drove the increase.
This doesn’t mean sparkling water causes weight gain. But if you’re using it as a tool to curb snacking between meals, it may not work as well as plain water for that specific purpose.
Do Artificial Sweeteners in Some Brands Matter?
Not all zero sugar sparkling waters are sweetener-free. Some brands add sucralose, stevia, or erythritol to enhance sweetness without calories. If your can lists only carbonated water and natural flavors, there’s no sweetener involved. But if you see a sweetener on the label, there are a few things to consider.
For most non-nutritive sweeteners, research generally shows no significant effect on insulin or blood sugar. Multiple studies have found that these sweeteners don’t trigger meaningful hormonal responses compared to plain water, especially when consumed as part of a normal meal pattern. Some studies have detected a slight increase in a gut hormone called GLP-1 from the sweet taste in the mouth, but this effect disappears when the sweetener bypasses the tongue entirely, suggesting it’s a taste response rather than a metabolic one.
Erythritol has drawn more attention recently. A 2025 study published in JACC: Advances followed over 4,000 older adults without existing heart disease and found that higher blood levels of erythritol were associated with increased risk of heart failure hospitalization, cardiovascular death, and overall mortality over roughly eight years of follow-up. Earlier research had linked elevated erythritol levels to a higher rate of major cardiovascular events across multiple patient groups. However, a Mendelian randomization study, which uses genetic data to test for cause and effect, did not find evidence that erythritol directly causes heart disease, diabetes, or kidney problems. The people with high erythritol levels in these studies also tended to be older, heavier, and more likely to have diabetes and high blood pressure, making it hard to separate erythritol’s role from the underlying health conditions. This research is still being sorted out, but it’s worth checking your labels if you consume erythritol-sweetened products frequently.
The Bone Density Myth
You may have heard that carbonated drinks weaken your bones. This concern comes from real research, but it applies to cola, not sparkling water. A major study using data from the Framingham Osteoporosis Study found that cola consumption was associated with lower bone mineral density in older women, likely because of the caffeine and phosphoric acid that colas contain. No such association was found for non-cola carbonated beverages. Plain sparkling water has neither caffeine nor phosphoric acid, so there’s no reason to worry about your bones.
Mineral Water vs. Standard Seltzer
If you’re choosing between types of sparkling water, naturally sparkling mineral water offers a small bonus. Depending on the brand, mineral water contains varying amounts of calcium, magnesium, and sodium absorbed from underground rock formations. Standard seltzer and club soda start as plain water with added carbonation and, in the case of club soda, added minerals like sodium bicarbonate. The mineral content in any of these is modest compared to food sources, but over time, mineral water can contribute to your daily calcium and magnesium intake in a small, effortless way.
The Bottom Line on Daily Use
For everyday hydration, zero sugar sparkling water is a solid choice. It keeps you hydrated, avoids sugar, and for most people causes no health issues. The main practical considerations: stick to plain or lightly flavored varieties most of the time to protect your enamel, be aware that carbonation may make you feel hungrier rather than fuller, and check labels for added sweeteners if you’d prefer to avoid them. If you have reflux or significant digestive sensitivity, flat water may be more comfortable, but for everyone else, drink up.