Plain sparkling water hydrates you just as well as still water and contains zero calories, making it a solid alternative to sugary drinks. But not all sparkling water is created equal. The type you choose, the flavors added, and even the brand can shift it from a genuinely healthy option to something worth a second look.
Hydration: Equal to Still Water
One of the most common questions about sparkling water is whether the carbonation somehow makes it 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 carbon dioxide bubbles don’t interfere with absorption or cause you to lose more fluid through urination. If swapping still water for sparkling helps you drink more throughout the day, you’re getting the same hydration benefit.
Types of Sparkling Water and What’s in Them
The sparkling water aisle has expanded dramatically, and the labels can be confusing. The differences matter more than you might think.
Seltzer is the simplest option: plain water with added carbonation and typically no minerals or sodium. A 12-ounce can contains 0% of the daily value for sodium. Club soda looks similar but is infused with added minerals like sodium bicarbonate and potassium sulfate, which bump the sodium content up to about 3% of your daily value per 12-ounce serving. That’s not much for most people, but it can add up if you’re drinking several cans a day or watching your sodium intake. Mineral water like Perrier or San Pellegrino comes from natural springs and contains minerals that were already present in the source. Tonic water is the outlier: it contains added sugar and calories, so it belongs in a different category entirely.
Most flavored sparkling waters use “natural flavors,” which the FDA defines broadly as extracts or essences derived from fruits, vegetables, spices, herbs, or other plant and animal sources. These are calorie-free flavoring agents, not artificial sweeteners, and they’re present in tiny amounts. If a sparkling water has no added sweeteners or calories on the label, flavored or not, it’s nutritionally close to plain water.
What It Does to Your Teeth
Carbonation makes water more acidic than its flat counterpart, and acid is what erodes tooth enamel. The concern is legitimate but often overstated. The American Dental Association has stated plainly that sparkling water is far better for your teeth than sugary drinks.
That said, not all sparkling waters are equally acidic. CBC Marketplace tested popular brands and found meaningful differences. Perrier’s grapefruit flavor had a pH of 5.46, LaCroix grapefruit came in at 4.71, and Bubly’s grapefruit was considerably more acidic at 3.86. Bubly’s cherry, grapefruit, and lime flavors all tested below a pH of 4. For context, tooth enamel starts to weaken below a pH of 5.5, and all tested sparkling waters fell below that threshold.
This doesn’t mean sparkling water will ruin your teeth. The exposure time is brief compared to sipping a soda throughout the day, and saliva neutralizes acid quickly. But if you’re drinking multiple cans daily, choosing a less acidic brand and not swishing the water around your mouth can reduce exposure. Drinking through a straw helps, though it may increase bloating (more on that below).
The Bone Health Question
You may have heard that carbonated drinks leach calcium from your bones. This concern comes from studies on cola, which contains phosphoric acid, an ingredient absent from sparkling water. When researchers looked specifically at non-cola carbonated drinks, they found no association with low bone mineral density.
A clinical trial published in the British Journal of Nutrition compared healthy postmenopausal women who drank about a quart of carbonated mineral water daily with women who drank the same amount of flat mineral water. After eight weeks, blood and urine markers for bone turnover showed no difference between the groups. Harvard Health’s assessment is straightforward: drinking seltzer water doesn’t appear to contribute to osteoporosis or increase fracture risk.
Effects on Digestion and Appetite
Carbonation and your gut have a complicated relationship. Some people find that sparkling water settles their stomach and reduces indigestion. Others experience bloating, gas, or discomfort, especially when they drink a lot of it. The carbon dioxide creates gas in your digestive tract, and for people with acid reflux, GERD, or irritable bowel syndrome, that extra pressure can worsen symptoms. UChicago Medicine recommends that people with these conditions switch to non-carbonated beverages if sparkling water seems to aggravate things. Drinking through a straw can make the bloating worse because you swallow more air along with the liquid.
There’s also an unexpected finding about appetite. A study had 20 men drink either carbonated or plain water, then measured levels of ghrelin, the hormone that signals hunger. Those who drank sparkling water, whether plain or artificially sweetened, had triple the ghrelin levels compared to those who drank flat water or degassed sparkling water. In a longer-term rat study from the same research team, animals drinking carbonated water gained more weight than those drinking still water. The researchers concluded that the carbon dioxide itself triggered increased ghrelin production. This is a single study and the effect in humans needs more investigation, but it’s worth knowing if you’re using sparkling water as a tool to manage hunger between meals. It may not suppress appetite the way many people assume.
Choosing the Healthiest Option
The healthiest sparkling water is one with no added sweeteners, no added sodium, and minimal acidity. Here’s how to pick well:
- Check for sweeteners. If the label lists sugar, high fructose corn syrup, or artificial sweeteners, it’s not plain sparkling water. Tonic water is the most common offender.
- Watch sodium. If you’re choosing between seltzer and club soda, seltzer is the lower-sodium choice at 0% of the daily value per can versus 3% for club soda.
- Consider acidity. Unflavored sparkling water tends to be less acidic than flavored versions. Among flavored options, brands vary significantly. Perrier tested less acidic than LaCroix, which tested less acidic than Bubly in head-to-head comparisons of the same flavors.
- Skip the straw. If bloating is a concern, drinking directly from the glass reduces the amount of air you swallow.
Natural mineral waters like Perrier and San Pellegrino contain trace minerals from their source, including calcium and magnesium. The amounts are modest and vary by brand, but they contribute small quantities of minerals you’d otherwise need to get from food. Whether this makes them nutritionally superior to plain seltzer depends on your overall diet, but it’s a minor bonus rather than a reason to choose them over other options.
For most people, sparkling water is a perfectly healthy daily drink. It hydrates identically to still water, poses no risk to your bones, and has a minimal impact on dental health compared to any sweetened beverage. The main people who should be cautious are those with existing digestive conditions like GERD or IBS, where the extra gas from carbonation can be genuinely uncomfortable.