Debunking the Sparkling Water Myth — Is Sparkling Water Bad for My Teeth?

By Dr. Adam Koppelman, DMD — Koppelman Dental, Midtown Manhattan Published: August 31, 2026

"But is LaCroix okay?" is, no exaggeration, in the top five questions I get asked in a given week. Ahead of "do you take my insurance?" Behind "is it going to hurt?" Somewhere along the way, the dental internet decided that sparkling water was quietly dissolving America's teeth, and now half my patients arrive at their cleaning appointment with a can of Spindrift in one hand and a guilty look on the other.

Meanwhile, the same patients — the good, motivated ones who quit Diet Coke, kicked Red Bull, or finally stopped nursing sweet tea from a Yeti — are now vaguely worried that they made the wrong swap. That the lime bubbles they replaced their Coke with are secretly just as bad. That somewhere, an enamel-loving TikTok dentist is going to catch them and shake their head.

Let me put this to rest. The swap was correct. Your teeth are grateful. But there is some nuance underneath the headline, and the nuance is actually useful.

The one number your enamel cares about

Enamel — the glassy, semi-translucent outer shell of your teeth — is the hardest tissue in the human body. It's also, unfortunately, non-living: no blood supply, no repair crew, no way to grow it back once it wears down. What you have at eighteen is largely what you get, and how you treat it decides how much of it you keep.

Enamel starts to soften and dissolve when the pH in your mouth drops below about 5.5. That's the number every dentist has memorized. Below 5.5, the calcium and phosphate that make enamel enamel start leaching out into your saliva. Above it, saliva can actually push those minerals back in — a process called remineralization. Your mouth is doing this dance, in miniature, every time you eat or drink anything.

The stakes:

If you take one thing away from this article: pH 5.5 is the number, and how far below it a drink sits — plus how long the drink stays in your mouth — is what actually determines the damage.

The new science: the July 2026 Purdue study

There's a brand-new study from Purdue University, presented at NUTRITION 2026 (the American Society for Nutrition's annual meeting), that measured salivary pH in real time as adults drank different beverages. This is different — and better — than most previous studies, which measured the pH of the drinks themselves rather than what was actually happening in a mouth.

The researchers had 20 adults drink four things on different days:

1. Regular soda
2. Plain unsweetened sparkling water
3. Calcium-fortified sparkling water
4. Plain still water (the control)

Then they measured how the pH in each subject's mouth changed at 5, 10, and 20 minutes after drinking.

The findings:

• Regular soda caused the biggest and longest-lasting pH drop. Twenty minutes later, subjects' mouths were still measurably acidic.
• Plain sparkling water caused a brief pH dip — but the dip stayed above the enamel-danger threshold, and saliva restored normal conditions within about twenty minutes.
• Calcium-fortified sparkling water performed similarly to plain sparkling water. The calcium didn't add much protective effect, but it didn't hurt either.
• Still water did roughly nothing to pH. As expected.

The lead researcher, Wajiha Zulfiqar, put it about as plainly as a scientist ever gets: "Replacing sugar-sweetened sodas with unsweetened sparkling water may help lower the risk of enamel erosion."

That is a permission slip, in academic dress. Consider it granted.

Why diet soda is genuinely worse than sparkling water

If you swapped Diet Coke for sparkling water and quietly wondered whether the two are basically the same acidic thing, the answer is no — they are not remotely the same.

Diet sodas drop the sugar, which removes the cavity side of the equation. But they keep the phosphoric acid and citric acid, which are the drivers of enamel erosion. And these are two different attacks on your teeth:

1. Cavities happen when bacteria in dental plaque eat sugar, ferment it into acid, and that acid drills a hole through your enamel over months or years. Cavities are localized — a hole here, a hole there. Sugar is fuel for this process.
2. Erosion is chemical dissolution. Any acid you put on enamel — dietary or otherwise — softens the surface. There are no bacteria involved. Erosion is global — it thins the whole enamel layer, especially on the front and biting surfaces of your teeth. You notice it as increased sensitivity to cold, yellowing (the underlying dentin showing through), thinning edges on the front teeth, and eventually a slightly shorter, more see-through smile.

Regular soda gets you both cavities and erosion. Diet soda gets you erosion, but no cavities. Sparkling water gets you neither, mostly.

This is why the swap is a genuine win. You didn't trade one enamel-killer for another. You traded a soda for something that lives comfortably above the danger line.

The sneaky middle ground: flavored seltzer

Here's where the internet gets its ammunition. A 2016 study published in the Journal of the American Dental Association tested a range of flavored waters and found that some — especially citrus flavors like lemon, lime, and grapefruit — dropped to a pH of about 3. That is comparable to Coca-Cola. That is a real number, and it is why every "sparkling water is destroying your teeth!" article you've ever seen keeps getting written.

But context matters. The 2016 study measured the pH of the drink in a beaker. The 2026 Purdue study measured what actually happened in a mouth. And what happens in a mouth is that saliva shows up almost immediately with buffering capacity — bicarbonate, calcium, phosphate — that neutralizes short-term acid exposure.

So the real answer on flavored seltzer is: it depends on how you drink it.

• A can of LaCroix with lunch, consumed in about ten minutes, is basically fine. Your saliva handles it.
• A can of LaCroix nursed slowly through a three-hour work session, so that your teeth are bathed in mildly acidic liquid the entire time, is a genuinely different situation. Saliva can't buffer what keeps arriving.

The pattern that actually matters is time-of-exposure. Chugging a mildly acidic drink is fine. Sipping the same drink all afternoon is not.

Also: not all flavors are equal. The citrus flavors — lemon, lime, grapefruit — are the worst offenders because citric acid is added deliberately for taste. The "essence of coconut" and "hint of berry" flavors, which are much subtler, are usually much less acidic. If you want a rule of thumb: the stronger the flavor, the more acid, roughly.

What actually decides your risk

Enamel erosion is a compound-interest problem. Small acid exposures, repeated many times a day, over many years, add up. The variables that determine your personal risk aren't really about what you're drinking — they're about the pattern.

Sipping vs. drinking

A single can of anything, consumed in ten minutes, is a rounding error. The same can, nursed at your desk for three hours, is a three-hour acid bath. If you're a serial sipper, the single most useful change you can make is to switch to drinking in sessions — full glass, drink it, done — rather than continuous exposure.

With food vs. alone

Meals dramatically boost saliva production. Food also physically buffers acids and provides calcium and phosphate. A can of seltzer with lunch is much less erosive than the same can consumed by itself at 3 PM.

Straws

They help, modestly. A straw aims the liquid past the front teeth (which are the ones you see, and therefore the ones that visible erosion matters on cosmetically). Straws don't solve the problem, but they redirect the exposure to teeth further back.

Do not brush immediately after

This is the one that surprises everyone. When you drink something acidic, your enamel is temporarily softened for about 20–30 minutes. If you brush during that window, you're mechanically scrubbing softened enamel — and you can accelerate wear noticeably.

The rule: after anything acidic, wait at least 30 minutes before brushing. If you want to feel like you're doing something in the meantime, rinse with plain water — that helps clear the acid and speeds up remineralization.

Xylitol gum

Chewing sugar-free gum, especially xylitol-based gum, after acidic exposures does two useful things: it boosts saliva flow (which buffers acid and delivers minerals) and, in the case of xylitol, actively suppresses cavity-causing bacteria. If you can't brush and can't rinse, gum is a reasonable third option.

Fluoride toothpaste, every day

Fluoride works by getting incorporated into the outermost layer of enamel and making it more acid-resistant. This is the boring but genuinely important daily habit. If you have significant erosion already, ask your dentist about prescription-strength (5000 ppm) fluoride toothpaste, which is dramatically more protective than the over-the-counter versions.

Who should actually worry

Almost nobody who drinks one or two plain sparkling waters a day. If that's you, close this tab and go enjoy your bubbles.

Worry more if:

• You sip citrus-flavored seltzer or diet soda more or less constantly through the workday.
• You have existing enamel wear, GERD (acid reflux), or dry mouth — some medications, especially antidepressants and antihistamines, dry the mouth out and remove your best natural defense.
• You have visible thinning at the edges of your front teeth, new cold sensitivity, or a smile that looks slightly more yellow than it used to (that's often dentin showing through thinning enamel).
• You have kids doing the same thing. Young enamel is still maturing and is more vulnerable to erosion than adult enamel.

The tells for actual enamel erosion, in a mirror:

• Cupping on the biting surfaces of the back teeth — small dished-out craters.
• Thinning translucency at the edges of the top front teeth. If they look slightly see-through or feel slightly rough on the biting edge, that's erosion.
• Yellowing — as enamel thins, the yellower dentin underneath shows through more.
• New sensitivity to cold — a big one, and usually the first symptom that gets a patient to book an appointment.

If any of that sounds like you, come in. We'll take a proper look, and if it's early, there are protective strategies that stop the process cold before you need any actual restorative work.

The five-second version

For the reader who scrolled to the bottom (I see you):

•  Plain sparkling water: basically fine for teeth. Enjoy freely.
•  Flavored seltzer: fine with meals, risky as an all-day desk drink. Citrus flavors are the worst.
•  Diet soda: not the enamel-safe hack it looks like. Erosion risk is real.
•  Regular soda: cavities and erosion. The worst of both worlds.
•  The real rule: it is not what you drink, it is how long you sip it and whether you brush too soon after.
•  Watch for: front-tooth thinning, cold sensitivity, yellowing at the edges. Those are erosion tells, not cavities.
•  Daily fluoride toothpaste is your best cheap defense. Ask about 5000 ppm if you have real wear.
•  Don't brush for 30 minutes after anything acidic. Rinse with plain water in the meantime.

Sources

• Zulfiqar et al., NUTRITION 2026 (Purdue University). Real-time salivary pH after soda, plain sparkling water, calcium-fortified sparkling water, and still water. Coverage: ScienceDaily, Newsweek.
• Reddy, Norris, Momeni, Waldo, Ruby (2016). Flavored waters at pH ~3, comparable to soda, published in the Journal of the American Dental Association. Coverage: Chicago Tribune, The Atlantic.
• Carbonated water effect on etched and sealed enamel. PMC review. Link.