Plain sparkling water is a perfectly healthy drink. It hydrates just as well as still water, contains zero calories, and doesn’t harm your bones. The caveats are mostly about what’s added to it (sweeteners, sodium, sugar) and how carbonation interacts with certain digestive conditions.
It Hydrates as Well as Still Water
One common concern is that the fizz somehow makes sparkling water less hydrating. It doesn’t. A study using the beverage hydration index, which measures how much fluid your body retains after drinking, found that sparkling water scored identically to regular water. The carbonation doesn’t speed up urination or reduce absorption. If you drink more water because you prefer the bubbles, that’s a net win for your hydration.
Sparkling Water Does Not Weaken Bones
The idea that carbonated drinks leach calcium from your bones comes from research on cola, not sparkling water. Cola contains phosphoric acid, which was suspected of interfering with calcium absorption. Even that concern hasn’t held up well under scrutiny. But the key point is that plain sparkling water doesn’t contain phosphoric acid at all.
A clinical trial published in the British Journal of Nutrition compared postmenopausal women who drank about a quart of carbonated mineral water daily with those who drank the same amount of flat mineral water. After eight weeks, blood and urine markers of bone turnover showed no difference between the groups. Non-cola carbonated drinks have never been linked to lower bone mineral density in studies.
Digestive Effects: Helpful for Some, Not for Others
Carbonation creates gas in your stomach, and that gas has to go somewhere. For most people, this means a bit of burping and maybe mild bloating that passes quickly. For people with acid reflux or GERD, the picture is more complicated. The gas expands the stomach, which can trigger the valve between your stomach and esophagus to relax temporarily. That relaxation lets stomach acid creep upward. Cross-sectional studies have found that people with GERD are about twice as likely to be regular carbonated beverage drinkers, and research suggests that nearly three-quarters of acid reflux episodes in some participants were triggered by belching.
If you already deal with frequent heartburn or have been told you have GERD, sparkling water may worsen your symptoms. If your digestion is otherwise fine, there’s no evidence that carbonated water causes reflux to develop in the first place.
The Hunger Hormone Question
One study worth knowing about found that carbon dioxide gas itself may stimulate appetite. Researchers at Birzeit University gave rats carbonated beverages over the course of a year and found they gained weight faster than rats given flat versions of the same drinks or plain tap water. The mechanism: carbonation increased levels of ghrelin, the hormone that signals hunger, leading to greater food intake. A parallel experiment in 20 healthy men showed the same ghrelin spike after drinking carbonated beverages.
This is a single study, and the rat portion involved long-term consumption. It doesn’t prove that your daily can of sparkling water will make you gain weight. But if you’ve noticed you feel hungrier after drinking fizzy water, there may be a hormonal explanation.
Potential Heart Health Benefits of Mineral Water
Not all sparkling water is identical, and the mineral content matters. Naturally carbonated mineral water often contains bicarbonate, calcium, magnesium, and sodium. Research on sodium-bicarbonate-rich mineral water has shown some surprisingly positive cardiovascular effects. In one study of young adults with moderately high cholesterol, drinking one liter per day for eight weeks reduced LDL (“bad”) cholesterol by 10% and total cholesterol by 6.3%. Systolic blood pressure also dropped significantly within the first four weeks.
Earlier research by the same group found similar results in postmenopausal women: lower total cholesterol, lower LDL, higher HDL (“good”) cholesterol, and reduced fasting blood sugar. Despite the mineral water containing about 1 gram of sodium per liter, it didn’t raise blood pressure in those women, likely because the other minerals in the water offset the sodium’s effects.
These findings apply specifically to bicarbonate-rich mineral water, not to all sparkling water. A can of plain seltzer won’t deliver the same mineral profile.
Know What Type You’re Drinking
The term “sparkling water” covers several very different products:
- Seltzer is just water with added carbonation. It contains no minerals, no sodium, and no calories.
- Club soda is carbonated water with small amounts of added minerals like sodium bicarbonate and potassium sulfate. It provides about 3% of your daily sodium value per 12-ounce serving.
- Sparkling mineral water comes from a natural spring and contains minerals from the source. A 12-ounce serving can deliver 9% of your daily calcium and 9% of your daily magnesium.
- Tonic water is the outlier. It contains quinine for its bitter flavor, plus sugar or high-fructose corn syrup. A 12-ounce serving packs 124 calories and 32 grams of sugar, roughly the same as a can of soda. Diet versions exist but swap in artificial sweeteners.
If you’re watching your calorie or sugar intake, tonic water is the one to avoid or limit. The other three are essentially calorie-free.
Watch for Hidden Ingredients in Flavored Versions
Flavored sparkling waters are enormously popular, and the ingredient lists vary more than you might expect. Many use “natural flavors,” which sounds straightforward but actually refers to flavor compounds created in a lab by extracting substances from plants or animals. They’re called “natural” because the source material is natural, even though the final product is engineered. These are generally considered safe, but if you’re trying to avoid all processed additives, it’s worth reading labels.
Some flavored sparkling waters also contain artificial sweeteners like stevia, aspartame, or sucralose to add sweetness without calories. If the ingredient list is just “carbonated water” and “natural flavors,” you’re getting something close to plain water. If it includes sweeteners, citric acid, or sodium, you’re drinking something a bit more processed. Neither is necessarily bad, but they’re not the same product.
Dental Erosion: Real but Minor
Carbonation makes water slightly acidic, with a pH typically around 3 to 4 for flavored varieties and closer to 5 for plain. That’s more acidic than flat water (pH 7) but far less acidic than orange juice or soda. Plain sparkling water poses minimal risk to tooth enamel. Flavored versions with added citric acid are more erosive, though still much less so than soft drinks or fruit juices. Drinking through a straw or rinsing with plain water afterward can reduce contact with your teeth if you’re concerned.