If you visit the dentist with a soda in hand, you’re bound to get some looks. Most folks know that sugar is bad for your teeth. But you won’t catch much flak if you’re sipping a Perrier. No sugar, no problem — right?
Still, an astute onlooker might wonder how sparkling water affects dental health. After all, carbonated water is mildly acidic, and acidic solutions can erode tooth enamel. And what about other carbonated beverages? Many popular drinks contain citric, malic, and other natural acids which can lower the pH of a beverage considerably. Submerge a tooth in lemon juice for a few days straight and it won’t fare well.
So, are sparkling waters, flavored sodas, and similar beverages a legitimate cause for concern? And what about LMNT? To answer these questions, I’ll review some cool science around acidity, carbonation, salivary flow, sugar, and dental health. Stick around for five minutes — you’ll learn a lot.
How Do Acidic Liquids Affect Your Teeth?
Tooth enamel is primarily made of a crystalline form of calcium and phosphate called hydroxyapatite. When you bathe hydroxyapatite in an acidic solution — say, lemon juice — it slowly demineralizes. If enough demineralization occurs, you see clinically concerning tooth erosion that causes dental pain, aesthetic issues, and increased risk of cavities.
Demineralization is, in a way, nature seeking balance. Lemon juice is acidic (due to its citric and malic acid content), so it likes to “borrow” alkaline minerals such as calcium and phosphate from teeth in order to neutralize itself. In return, it donates hydrogen ions, acidifying tooth enamel. Bad deal for the enamel, but hey… that’s chemistry.
Most of us aren’t bathing our chompers in lemon juice, so let’s bring this example into the real world. Leaving the dental harms of sugar aside (we’ll cover that in a moment), the erosion potential of a beverage depends on three main factors:
- The acidity of the liquid
- The pH and flow rate of your saliva
- How long your teeth are exposed to the liquid
Let’s cover each of them now.
#1: The acidity of the liquid
All solutions which contain water can be assigned a pH value — a measure of how many free hydrogen ions (H+) are in the solution. Water is the neutral reference point, with a pH of 7. Solutions with a greater concentration of H+ than water are acidic, with a pH between 0 and 7. Solutions with a lesser concentration of H+ than water are basic, with a pH between 7 and 14.
The more acidic the beverage, the greater the risk of tooth erosion. A 2015 Journal of the American Dental Association study did a superb job quantifying the pH levels and relative erosion risks of hundreds of beverages. Check out the pH stats below. The bracketed lines indicate the range of pH values for a category of beverages, and the dots indicate average pH.
- Municipal tap water had a pH of 7.2
- Coffee had a pH of 5.11
- 2 sparkling mineral waters (Pellegrino and Perrier) had pHs of 4.96 and 5.25
- 51 juices had an average pH of 3.48, with a range of 2.25–4.69
- 17 teas had an average pH of 3.48, with a range of 2.85–5.18
- 94 sodas had an average pH of 3.12, with a range of 2.32–5.24
- 68 energy drinks had an average pH of 3.13, with a range of 2.47–3.97
- lemon juice (pH of 2.25) and various colas (pH of 2.3–2.4) were the most acidic beverages
Researchers categorized the erosion risk of 3 pH ranges based on studies that assessed how easily hydroxyapatite (your tooth enamel’s main mineral) dissolves. They decided that:
- Drinks with a pH < 3.0 are extremely erosive
- Drinks with a pH between 3.0–3.99 are erosive
- Drinks with a pH ≥ 4.0 are minimally erosive
It’s important to understand that a strong acid is much more erosive than a weak acid. In lab studies, a solution’s ability to erode tooth enamel increases ten times with each one-point drop in pH. In other words, a beverage with a pH of 3 is ten times more erosive than a beverage with a pH of 4, and 100 times more erosive than a beverage with a pH of 5.
According to these criteria, most juice, soda, tea, and energy drinks are considered erosive or extremely erosive. Why? Whether naturally occurring or added in the manufacturing process, most of these beverages contain citric acid, malic acid, or phosphoric acid, which provide a nice tart flavor and improve shelf life.
Coffee and sparkling water are minimally erosive. Coffee makes sense: It contains small concentrations of a variety of naturally occurring acids (including citric and malic acid). But you may be surprised that sparkling water is mildly acidic — shouldn’t it be neutral, just like still water? It’s a reasonable assumption, but water (H2O) can interact with the carbon dioxide (CO2) bubbles to form carbonic acid (H2CO3). This can slightly reduce pH and increase acidity, but likely not enough to cause serious tooth erosion.
In fact, sparkling mineral water often contains calcium and phosphorus ions that reduce acidity in the mouth and help remineralize teeth. This 2022 study, for example, found that mineral water slightly alkalinized saliva. These properties may help defend against dental decay.
#2: Saliva characteristics
Saliva is enamel-friendly because it has a pH range between 6.2–7.6. When an acidic drink causes the pH of your mouth to drop, saliva usually neutralizes the shift within a couple of minutes. The calcium and phosphate ions in your saliva help maintain pH and dental mineral balance. Some folks have more minerals in their saliva than others, increasing their protection against acidic drinks.
Along with minerals, the flow rate of saliva matters, too. Higher flow rates clear acid faster and limit erosion. In a 2003 study, children with erosive tooth lesions had about half the flow rate (0.6 mL/min) of healthy controls (1.1 mL/min). Other researchers found that salivary flow decreased after exercise, possibly explaining why the study’s active young folks showed more dental wear than their sedentary counterparts.
Relevant here, another study found that carbonation increased salivary flow about three times more than still water. A sour taste had an even more significant effect, increasing salivary flow about five times more than plain H2O. Temperature plays a role too — the colder the beverage, the faster you salivate. Practically speaking, I don’t know anyone who needs to be convinced to stop drinking warm soda (gross). Still, it’s a neat fact.
#3: Length of exposure
It’s common sense that the longer you expose your teeth to an acidic solution, the more dental erosion will occur. The lab data bears this out.
Since experimenting with these effects in human mouths is impractical and unethical, we turn to observational data. In a 2002 study, Saudi men who held beverages (including cola) in their mouths for 78% longer (71 seconds vs. 40 seconds) had more erosion. Another paper found that dental wear correlated with “the habit of holding drinks in the mouth before swallowing” in six-year-old Brazilian children.
What Other Factors Influence the Race to Neutral pH?
After you drink an acidic beverage, saliva creeps in to neutralize your mouth’s pH. It seems sugar content and total acid content (titratable acidity) may influence how quickly saliva is able to return your pH to baseline levels.
#1: Sugar content
A 2022 RCT (randomized controlled trial) found that salivary pH was not significantly affected after drinking 12 ounces of either sparkling water, still water, or sugar-free soda. Drinking a sugary soda, however, led to more acidic saliva for up to 45 minutes, with the largest drop in the first few minutes. Why was the sugary soft drink more acidifying than its sugar-free counterpart?
It’s the sugar, the authors believe. Sugar feeds certain oral bacteria, creating harmful organic acids that erode your tooth enamel. One such bacterium, streptococcus mutans, is a significant driver of cavities. Sugar seems to slightly lower your mouth’s pH on its own, and may affect how long it takes to neutralize salivary pH. When combined with a low-pH beverage, though, sugar’s harmful effects may be amplified.
#2: Titratable acidity
Another study employed a different design. Researchers had participants hold a tiny amount (15 mL) of either cola, orange juice, or sugar water in their mouths for ten seconds, then spit it out. Afterward, they measured salivary pH. Sugar water had little effect, cola lowered pH for 30 seconds, and orange juice lowered pH for 90 seconds.
These beverages all had similar sugar content. So why the difference between cola and OJ? It wasn’t the pH. In fact, cola had a lower pH at 2.5 compared to orange juice at 3.5. The orange juice has a higher titratable acidity, which is a measure of ALL acids in a solution — not just the free hydrogen ions measured by pH. The authors think that pH affects erosivity during consumption, and that titratable acidity influences how long it takes to restore pH levels to baseline after consumption.
Lessons and Takeaways
We covered a TON of science today. I’ll recap it here, plus offer practical advice to optimize your hydration habits for oral health.
Erosion risk in the lab isn’t the same as erosion risk in the real world. In the lab, scientists bathe hydroxyapatite (the tooth enamel mineral) in acidic solutions for hours. In the real world, you expose teeth to common flavors like citric, malic, and phosphoric acid for a few seconds, and saliva kicks in to bring the mouth’s pH back to baseline. This doesn’t mean acidic solutions are good for your teeth (they’re not), but they may be less harmful than in vitro data suggests.
Carbonated water alone isn’t acidic enough to damage your teeth. At a pH of around 5, I wouldn’t fret over sparkling water ruining your pearly whites. Sparkling mineral water may even have some positive influence on dental health by alkalinizing the mouth and remineralizing teeth — but more research is needed.
Sour, cold, and sparkling properties increase salivary flow. A greater flow of saliva reduces erosion risk. Sour sensations stimulate about 5X more saliva than plain water, and carbonated water stimulates about 3X more than still water. Colder beverages improve salivary flow compared to warmer ones, too.
Swishing and holding increase erosion risk. Don’t swish or hold acidic liquids in your mouth. Just drink them.
Try rinsing your mouth with plain water after your low-pH beverage. There isn’t much data on this practice, but it can’t hurt. The water may act as a substitute for saliva, helping to neutralize oral pH. Rinsing may be especially handy for folks who exercise, since salivary flow may decrease following a workout.
Watch out for sugary, acidic beverages. Most of the correlational data on dental erosion is on drinks like orange juice and ordinary sodas, which are both acidic AND sugary. Additionally, sugar feeds acid-producing oral bacteria, among other health risks. While sugar water alone may not acidify your mouth, the research suggests that sugar can influence oral pH — especially when paired with acidic compounds.
What About LMNT?
Similar to just about any drink mix, tea, juice, or other beverage you’ll find on the market, certain flavors of LMNT contain citric acid and/or malic acid, plus natural flavors. LMNT Sparkling is also carbonated. These ingredients give it a fairly low pH, but one that is pretty common in the beverage industry.
We do not measure the pH of LMNT Drink Mix during production because it is only added to water once it reaches you. We do measure the pH of LMNT Sparkling — which ranges between 2.60–3.17 — because it is already in water.
With any product, there are tradeoffs. It might be helpful to note that LMNT contains zero sugar and has several characteristics (sour taste, cold temperature, and bubbles in LMNT Sparkling) that significantly boost saliva production, helping to restore the pH of the mouth more quickly.
Recall the 2022 RCT comparing sugary soft drinks with sugar-free ones? Despite almost identical compositions, only the sugary soft drink produced a prolonged drop in salivary pH. While discussing this contrast, the authors wrote that this effect “can be attributed more to its sucrose [sugar] content and not to other compounds such as phosphoric and citric acid.”
With regard to each of these tradeoffs, we’re confident that the benefits of healthy hydration far outweigh the potential impact of LMNT’s pH. If you’re worried about the potential dental impacts of acidic beverages, you can always rely on our Chocolate Salt, Chocolate Caramel, and Raw Unflavored drink mix to get your electrolytes in — these options do not contain citric acid or malic acid.
You can also make LMNT at home with your preferred ingredients using the free recipe in this article. We encourage you to Stay Salty however works best for you.
