Is Carbonated Water Good For You? What the Research Actually Says

What Is Carbonated Water?

Carbonated water is plain water with carbon dioxide gas dissolved into it under pressure. When you crack open a bottle or press the button on a soda maker, that pressure drops and the CO2 escapes as bubbles. That's where the fizz comes from.

It goes by a lot of names: sparkling water, seltzer, soda water, fizzy water. They're all basically the same thing, with a couple of exceptions worth knowing about.

Club soda has small amounts of minerals added, like sodium bicarbonate or potassium sulfate. It tastes slightly salty. Tonic water is a different product altogether: it contains sugar (or sweeteners) and quinine, which gives it that bitter taste. A can of tonic water can have as much sugar as a soft drink. Sparkling mineral water (like Perrier or San Pellegrino) is naturally carbonated or has CO2 added to water that already contains minerals from its source.

For this guide, we're talking about plain carbonated water, no sugar, no sweeteners, no added flavours. Just water and bubbles.

Does Carbonated Water Hydrate You?

Yes. Carbonated water hydrates you just as well as still water.

A 2016 randomised trial published in the American Journal of Clinical Nutrition developed something called a Beverage Hydration Index (BHI), which measures how well different drinks keep you hydrated by tracking urine output after consumption. The study, led by Ronald Maughan and colleagues, tested 13 different beverages and found that sparkling water performed identically to still water for hydration.

This makes sense when you think about it. The base of carbonated water is still H2O. The dissolved CO2 doesn't interfere with your body's ability to absorb the water. It just adds bubbles.

One practical benefit: some people find they drink more water when it's sparkling because they enjoy it more. If switching from sugary drinks or juice to sparkling water means you stay better hydrated, that's a genuine win.

Does It Damage Your Teeth?

This is the concern you'll see most often, and it deserves a careful answer.

Carbonated water is slightly acidic. When CO2 dissolves in water, it forms carbonic acid, which drops the pH to somewhere between 3 and 5, depending on the level of carbonation. For context, still water sits around 7 (neutral), orange juice is around 3.5, and cola is about 2.5.

But acidity alone doesn't tell the whole story. What matters for enamel erosion is how aggressive that acid actually is, and carbonic acid is a weak acid.

A 2001 study by Parry et al. in the Journal of Oral Rehabilitation tested mineral waters and soft drinks for their erosive potential on tooth enamel. The results were clear: sparkling mineral waters showed slightly more enamel dissolution than still water, but the levels were roughly one hundred times less than soft drinks. The researchers also found that degassing a sparkling water (removing the CO2) reduced its erosive effect even further, suggesting that carbonation itself isn't a major factor compared to the strong acids in soft drinks.

A separate study in the Journal of the American Dental Association categorised the erosive potential of common beverages. Most sparkling waters ranked as "minimally erosive" (pH above 4.0), while many sports drinks and sodas were classified as "extremely erosive."

The American Dental Association has said that plain sparkling water is "generally fine for your teeth" under normal drinking conditions.

There's one important caveat. Flavoured sparkling waters are a different story. Many contain citric acid for taste, which can bring the pH down to 3.0 or lower, putting them in the same erosive range as diet soft drinks. We'll cover that more in a later section.

The bottom line on teeth: plain carbonated water, without added citric acid or sugar, poses minimal risk to your enamel. It's not in the same league as soft drinks, juice, or sports drinks.

Does It Affect Bone Health?

This myth has been around for years: drinking carbonated beverages weakens your bones. But the research tells a more nuanced story.

The Framingham Osteoporosis Study, published in the American Journal of Clinical Nutrition in 2006, looked at more than 2,500 participants and measured bone mineral density (BMD) at the spine and three hip sites. The findings? Cola intake was associated with lower BMD in women, but other carbonated beverages, including plain sparkling water, showed no such association.

The researchers pointed to phosphoric acid, an ingredient specific to cola, as the likely culprit. Phosphoric acid can interfere with calcium absorption and contribute to mineral imbalances. Caffeine, another common ingredient in cola, has also been identified as a risk factor for bone density loss.

Plain carbonated water doesn't contain phosphoric acid or caffeine. There's no credible evidence linking it to bone density problems.

A Harvard Health review of the evidence reached the same conclusion: "If the fizzy water you choose is plain carbonated water, there is no reason to think it would be harmful to your bones."

Does It Cause Bloating or Digestive Issues?

This one is genuinely mixed, and it depends on who you are.

When you drink carbonated water, you're swallowing dissolved CO2 gas. Some of that gas gets released in your stomach, which can cause temporary bloating, burping, or a feeling of fullness. For most people, this passes quickly and isn't a problem.

But if you have irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD), or other functional digestive issues, carbonated water may make symptoms worse. People with IBS often have heightened sensitivity to gas and distension in the gut. Even a normal amount of intestinal gas can register as painful bloating because the nerve signals are amplified. Johns Hopkins Medicine lists carbonated beverages among the foods IBS sufferers may want to limit.

On the flip side, there's a study that suggests carbonated water might actually help with certain digestive problems.

A 2002 double-blind randomised trial by Cuomo et al., published in the European Journal of Gastroenterology and Hepatology, studied 21 patients with functional dyspepsia (chronic indigestion) and constipation. Half drank carbonated water for 15 days; the other half drank tap water. The carbonated water group showed significant improvements in both dyspepsia and constipation scores. They also had improved gallbladder emptying.

It's a small study with some design limitations (it's hard to truly blind participants to whether their water is fizzy), but the results are interesting and consistent with anecdotal reports from people who find sparkling water helps their digestion.

The practical takeaway: if you have IBS or GERD, go easy on the bubbles and see how your body responds. If you don't have those conditions, temporary bloating is the worst you're likely to experience.

Are There Actual Benefits?

Carbonated water won't cure anything. But there are a few evidence-backed benefits worth mentioning.

It may improve swallowing ability. Multiple studies have found that carbonated water can stimulate the nerves responsible for swallowing. A 2012 study published in Dysphagia found that carbonation increased swallowing muscle activity and triggered a faster, stronger swallow response. This has practical applications for elderly people and patients with neurogenic dysphagia (difficulty swallowing due to nervous system conditions). Some speech therapists already use carbonated liquids as part of swallowing rehabilitation.

It can help with constipation. The Cuomo et al. study mentioned above found that carbonated water significantly improved constipation scores compared to tap water over a 15-day period. While we need more research, this is a low-risk option for people dealing with sluggish digestion.

It may increase feelings of fullness. Research shows that carbonated water can increase feelings of satiety compared to still water. The CO2 released in the stomach causes distension, which triggers stretch receptors that signal fullness to the brain. This could be helpful if you're trying to manage portion sizes, though it's not a weight loss tool on its own.

It helps people drink more water. This sounds simple, but it matters. If you find plain still water boring, having sparkling water available can help you hit your daily fluid intake. Hydration compliance is a real challenge, especially in Singapore's climate, where you're losing fluid to sweat throughout the day. Anything that helps you drink more water is a good thing.

What About Flavoured Sparkling Water?

Not all sparkling water is created equal. Plain carbonated water and flavoured sparkling water can be very different products.

Many flavoured sparkling waters contain citric acid, which is added for a sharper, more refreshing taste. Citric acid drops the pH significantly and increases the erosive potential on tooth enamel, sometimes to levels comparable with diet soft drinks. Some brands also add sugar, artificial sweeteners, or sodium, which changes the health profile entirely.

Read the ingredients label. What you're looking for is short and simple: carbonated water, and maybe "natural flavour." Watch out for:

• Citric acid (increases enamel erosion risk)
• Sugar or high fructose corn syrup (cavity risk, extra calories)
• Artificial sweeteners (aspartame, sucralose, acesulfame K)
• Sodium (relevant if you're monitoring salt intake)

If you want flavoured sparkling water without the downsides, try adding your own fresh fruit. A few slices of cucumber, lemon, lime, or strawberry in your glass gives you flavour without the concentrated citric acid that comes in pre-flavoured products. Just note that even fresh citrus will slightly increase the acidity, so don't leave it soaking for hours.

Making Your Own Sparkling Water at Home

The easiest way to control exactly what's in your sparkling water is to make it yourself. There are a few options.

Soda makers like SodaStream are the most popular choice. You fill a reusable bottle with water, press a button to inject CO2, and you've got sparkling water in seconds. The CO2 cylinders are refillable, so you're not generating single-use plastic bottles. Each cylinder typically makes around 60 litres of sparkling water.

CO2 siphons are the old-school version. They use small CO2 cartridges to carbonate water in a pressurised bottle. They're compact and portable, but the per-litre cost is higher than a soda maker.

All-in-one systems combine water purification and carbonation in a single unit. The HydroSpark is one example: it filters and purifies your tap water before carbonating it, so you get clean sparkling water without needing a separate purifier. This approach makes sense if you want to skip the extra step of pre-filtering, and it means you're not starting with water that still has residual chlorine taste.

There's a sustainability angle here too. Making sparkling water at home eliminates single-use plastic bottles entirely. SodaStream estimates that each machine prevents around 500 plastic bottles from entering the waste stream per year. In Singapore, where we go through a significant volume of bottled water, that adds up.

If your household drinks a lot of sparkling water, a home system pays for itself within a few months compared to buying bottled brands. And you can control the carbonation level, from lightly fizzy to aggressively bubbly, depending on your taste.

For anyone in Singapore thinking about water quality beyond carbonation, our guide to choosing a water purifier covers what you should know about local tap water and filtration options.

Frequently Asked Questions

Can kids drink sparkling water?

Plain sparkling water is generally safe for children. Paediatric dentists note that it's a much better option than soft drinks or juice. That said, still water should remain the main drink for young children. If your child does drink sparkling water, choose plain (unflavoured) varieties and consider using a straw to reduce contact with teeth. Avoid giving sparkling water to children under 3, as they don't need flavoured or bubbly drinks and it may displace milk or plain water intake.

Is sparkling water bad for your kidneys?

There's no evidence that plain carbonated water is harmful to healthy kidneys. A study published in Epidemiology found that cola consumption was associated with increased risk of chronic kidney disease, but non-cola carbonated beverages showed no such link. The concern with cola is the phosphoric acid, not the carbonation. Interestingly, some research suggests that the bicarbonate content in certain mineral waters may actually be beneficial for kidney stone prevention by increasing urinary pH.

How much sparkling water is too much?

There's no official upper limit. Most health professionals suggest that one to three glasses (roughly 250 ml to 750 ml) per day is perfectly fine for most people. Some people drink a litre or more daily without issues. The main thing to watch for is digestive discomfort: if you're getting excessive bloating or gas, cut back. It's also sensible to drink some plain still water alongside your sparkling water rather than making fizzy water your only fluid source.

Does carbonated water make you gain weight?

Plain carbonated water has zero calories and zero sugar, so it can't directly cause weight gain. Some research has explored whether carbonation affects appetite hormones, but the evidence is mixed and inconclusive. What's clear is that replacing sugary sodas with plain sparkling water removes a significant source of empty calories from your diet, which supports weight management rather than working against it.

Is carbonated water bad for acid reflux?

It depends on the individual. The carbonation can cause stomach distension, which may trigger reflux symptoms in people who are already prone to GERD. If you experience heartburn or acid reflux after drinking sparkling water, it's worth reducing your intake or switching to still water. For people without reflux issues, carbonated water isn't likely to cause problems.

Is sparkling water better than regular water?

Neither is objectively "better." They hydrate equally well and have the same basic composition. Sparkling water has a few modest advantages (may help with swallowing and constipation, can make hydration more enjoyable) and a few minor drawbacks (can cause temporary bloating, slightly more acidic). Choose whichever one helps you drink enough water throughout the day. For most people, a mix of both works well.