Plain sparkling water is not bad for you. It hydrates just as well as still water, doesn’t harm your bones, and poses minimal risk to your teeth. The concerns most people have heard about are either overstated or apply specifically to sodas and colas, not to simple carbonated water. That said, a few nuances are worth knowing, especially around dental health, digestion, and what’s actually in your bottle.
Hydration Is the Same
Sparkling water hydrates your body just as effectively as flat water. The carbonation doesn’t interfere with absorption or change how your kidneys process the fluid. If you find it easier to drink enough water when it’s fizzy, that’s a net positive for your health. The one practical caveat: the bubbles can make you feel full faster, which might mean you drink less during intense exercise. For everyday hydration, though, sparkling and still water are interchangeable.
What It Does to Your Teeth
This is the concern with the most truth to it, but the actual risk is small. When carbon dioxide dissolves in water, it forms a mild acid called carbonic acid. That drops the pH of sparkling water to roughly 4.9 to 5.9 depending on the brand and carbonation level. Tooth enamel starts to dissolve below a pH of about 5.5, so some sparkling waters do dip into that range.
In practice, the effect is minimal. The American Dental Association notes that research comparing sparkling water and still water found the two were “about the same in their effects on tooth enamel.” Plain carbonated water is far less erosive than sodas, juices, or sports drinks, which combine higher acidity with sugar.
The real risk comes from two things: citrus flavoring and sipping habits. Citrus-flavored sparkling waters have higher acid levels than plain varieties. And if you nurse a can of sparkling water over several hours, you’re bathing your teeth in mild acid repeatedly. A better approach is to drink it in one sitting or with a meal, then follow up with plain water. Brands with added sugar are a different category entirely and carry real cavity risk.
Bones and Osteoporosis
The idea that carbonated water weakens bones is one of the most persistent myths about sparkling water, and it’s wrong. This belief likely comes from research on cola, which does show an association with lower bone density at the hip in women. But cola contains phosphoric acid, which is a completely different substance from the carbonic acid in sparkling water.
A clinical trial published in the British Journal of Nutrition tracked healthy postmenopausal women who drank about a quart of carbonated mineral water daily for eight weeks, compared with women drinking the same amount of still mineral water. Blood and urine tests measuring bone turnover showed no difference between the groups. The carbonation itself has no effect on calcium loss or bone strength.
Digestion and Acid Reflux
Carbonation releases gas in your stomach, which can cause bloating, burping, and discomfort, particularly if you drink a lot of it quickly. For most people this is harmless, if occasionally awkward.
If you have gastroesophageal reflux (GERD), the picture is a bit more complicated. A large study of women’s health found that those with the highest soda intake had a 29% higher risk of developing reflux symptoms compared to non-drinkers. Replacing two daily servings of soda with water reduced that risk. The study grouped all carbonated soft drinks together, so it’s hard to separate the effect of carbonation alone from the sugar, caffeine, and acids in soda. Still, if you already deal with reflux, paying attention to whether sparkling water triggers your symptoms is reasonable.
Kidneys Are Fine
Cola drinks have been linked to kidney stone formation because of their phosphoric acid content, which changes urine composition in ways that promote calcium oxalate stones. In a randomized trial of men with a history of kidney stones, those who kept drinking phosphoric acid beverages had more recurrences than those who switched to citric acid drinks.
Non-cola carbonated beverages showed no increased risk. Plain sparkling water, seltzer, and mineral water don’t contain phosphoric acid, so this concern simply doesn’t apply to them. Staying well-hydrated with any type of water is one of the most effective ways to prevent kidney stones in the first place.
Not All Bubbly Water Is the Same
The label matters more than the bubbles. Here’s how the main types differ:
- Seltzer water is just water plus carbon dioxide. It contains no sodium and no added minerals.
- Club soda has added minerals, including about 75 mg of sodium per 12-ounce serving. That’s not a lot, but it adds up if you drink several cans a day and are watching your sodium intake.
- Mineral water comes from a natural source and contains varying amounts of calcium, magnesium, and other minerals. The specific content depends on the brand and spring.
- Flavored sparkling water ranges from harmless (natural flavors, no sweetener) to essentially soda (added sugar or citric acid). Check the ingredients.
If you’re drinking plain seltzer or unflavored sparkling mineral water, you’re drinking water with bubbles. Nothing more.
The Hunger Hormone Question
One animal study found that rats given carbonated beverages over about a year gained weight faster than rats given flat versions of the same drinks or tap water. The researchers traced this to higher levels of ghrelin, a hormone that signals hunger, which led the rats to eat more. A smaller parallel experiment in 20 healthy men also found elevated ghrelin levels after drinking carbonated beverages.
This is worth mentioning because it circulates widely online, but context matters. The study used carbonated beverages broadly, not just plain water. A single study in rats with a small human component doesn’t establish that your daily LaCroix is making you gain weight. No large human trials have confirmed this effect for plain sparkling water specifically. It’s an interesting data point, not a reason to change your habits.
The Bottom Line on Bubbly Water
Plain sparkling water is a perfectly healthy drink. It hydrates you, doesn’t weaken your bones, and carries only a trivial risk to your teeth if you drink it reasonably. The main things to watch for are added sugar, citrus flavorings that increase acidity, and sodium in club soda. If you enjoy it, keep drinking it.