Is the Carbon in Carbonated Water Bad for You?

December 2, 2025 •

4 min read

Over a third of American adults consume sparkling water daily, yet myths about its safety persist. The central concern revolves around whether the carbon in carbonated water is bad for you, with worries ranging from dental damage to digestive issues. In reality, the carbonation itself is largely harmless for most people, but the health implications depend heavily on the type of beverage and individual sensitivity.

Quick Summary

Separating myth from fact about carbonation's health effects, this article clarifies that plain carbonated water is generally safe. It explores how the gas affects teeth and digestion, distinguishing between plain seltzer and sugary sodas. The key takeaway is that for most, carbonation is not inherently harmful, but personal tolerance and added ingredients matter most.

Key Points

Not Inherently Harmful: The carbon dioxide in carbonated water is not toxic and is safely expelled by the body through burping and respiration.
Minimal Dental Risk (Plain): Plain sparkling water is mildly acidic but poses minimal risk to tooth enamel compared to sugary and fruit-flavored sodas that contain more aggressive acids.
Bloating and Gas: For sensitive individuals, the carbonation can cause bloating, gas, or aggravate symptoms of conditions like IBS and GERD, but this varies from person to person.
No Bone Density Loss: Unlike some colas containing phosphoric acid, plain carbonated water does not cause bone mineral density loss.
Aids Digestion and Hydration: Sparkling water is just as hydrating as still water and can aid digestion and alleviate constipation for some individuals.
Beware of Additives: The main health risks come from additives like sugar, artificial sweeteners, and sodium found in flavored or club soda varieties, not from the carbonation itself.
Moderation is Key: Enjoying plain carbonated water in moderation is safe for most healthy adults and is a better alternative to sugary soft drinks.

What is Carbonated Water?

Carbonated water is simply water infused with carbon dioxide ($CO_2$) gas under pressure. This process creates the characteristic fizz and forms a weak carbonic acid, which slightly lowers the water's pH. The variations of carbonated water include seltzer, club soda (which contains added minerals), and sparkling mineral water (which is naturally carbonated at the source). While plain seltzer is just water and $CO_2$, many flavored varieties may contain additional ingredients like citric acid, artificial sweeteners, or natural flavors. Understanding the subtle differences between these products is crucial for assessing their overall health impact.

The Impact of Carbonation on Dental Health

One of the most persistent concerns is that the carbonic acid in sparkling water will erode tooth enamel. While it's true that carbonated water is mildly acidic, it is significantly less erosive than sugary sodas or fruit juices. A dental study published in the Journal of Oral Rehabilitation found that sparkling water had a minimal effect on tooth enamel compared to soda and orange juice. The risk to dental health is not from carbonation alone but from added sugars and flavorings, especially citrus-based acids, which can lower the pH to more damaging levels. For example, a lemon-flavored sparkling water is more acidic than its unflavored counterpart. The risk is also heightened by frequent sipping, which gives saliva less time to neutralize the acidity in the mouth.

Best practices for protecting your teeth:

Drink plain, unflavored carbonated water over flavored versions.
Use a straw to minimize direct contact with your teeth.
Drink carbonated water with a meal to stimulate saliva production.
Rinse your mouth with plain water after drinking sparkling water.

Effects on the Digestive System

For many, carbonated water is not only harmless but can also aid in digestion. Studies show it can help improve swallowing ability and relieve constipation. The bubbles may help food move through the digestive system more efficiently. However, the effect varies by individual. For those with sensitive stomachs, particularly those with conditions like Irritable Bowel Syndrome (IBS) or Gastroesophageal Reflux Disease (GERD), the added gas can be problematic. The carbon dioxide can cause bloating, gas, and stomach pain as the gas expands in the stomach. It can also increase pressure in the stomach, potentially pushing stomach acid into the esophagus and triggering heartburn. If you notice increased discomfort, it's best to switch back to still water or reduce your intake.

Carbonated Water and Bone Health: Busting the Myths

Myths about carbonated water leading to bone density loss are a common source of misinformation. Decades of research have shown that the problem isn't carbonation but the ingredients found in certain sugary sodas. Specifically, colas contain phosphoric acid, which can interfere with calcium absorption when consumed in large amounts, potentially harming bone density. Plain carbonated water, lacking this ingredient, does not have the same effect. Some sparkling mineral waters even contain calcium and magnesium, which can be beneficial for bone health. Therefore, the carbonation itself is innocent when it comes to weakening bones.

Comparison Table: Plain Carbonated Water vs. Sugary Soda


Feature	Plain Carbonated Water	Sugary Soda (e.g., Cola)
Carbonation Source	Carbon dioxide (or naturally occurring in mineral water)	Carbon dioxide
Acidity Level (pH)	Mildly acidic (pH 5-6)	Very acidic (pH 2.5-3.5)
Dental Risk	Minimally erosive over long periods; low risk	Highly erosive due to high sugar and acid
Digestive Effects	Can cause bloating/gas in sensitive individuals; may aid digestion for others	Can worsen bloating, gas, and reflux; sugar can cause diarrhea
Impact on Bones	No negative impact on bone density	Phosphoric acid can lead to lower bone density with high intake
Added Ingredients	None in pure seltzer; mineral versions contain minerals; flavored versions can contain citric acid	High-fructose corn syrup, phosphoric acid, artificial flavors
Hydration	Just as hydrating as still water	Less effective for hydration due to high sugar content
Calories	Zero calories	High in calories

Potential Risks and How to Mitigate Them

While the carbonation itself is safe for most, certain individuals should be mindful of their intake. As noted, those with chronic digestive issues like GERD or IBS may experience aggravated symptoms due to bloating. Pregnant individuals experiencing heartburn might also want to limit consumption. Furthermore, while rare, some studies have noted a slight uptick in the hunger hormone ghrelin in animal studies, suggesting it could potentially increase appetite, though human studies are inconclusive. As with anything, moderation is key. Plain carbonated water offers a healthy and hydrating alternative to sugary beverages, but listening to your body is the most important factor. The primary health risks associated with sparkling water are not from the bubbles but from added ingredients like sugars and excessive sodium. Opting for unsweetened and low-sodium brands is the best way to enjoy the fizz without the fuss. The National Institutes of Health provides extensive resources on dietary health and ingredient impacts.

Conclusion

Ultimately, the science is clear: the carbon in carbonated water is not bad for you in and of itself. The perception of risk is often conflated with the negative health effects of sugary sodas, which contain far more damaging ingredients like excessive sugar and phosphoric acid. For a majority of healthy people, plain sparkling water is a perfectly safe and hydrating alternative to plain water. It even offers some digestive benefits, such as relieving constipation and improving swallowing ability. The minor risks, primarily related to dental enamel erosion and digestive discomfort, are largely manageable by choosing unflavored varieties, drinking in moderation, and using a straw. By staying informed and paying attention to your body's signals, you can confidently enjoy a refreshing, bubbly beverage as part of a healthy lifestyle.

Frequently Asked Questions

Plain, unflavored carbonated water is only minimally erosive to tooth enamel and significantly less damaging than sugary sodas or fruit juices. Flavored versions, especially those with citrus acids, are more acidic and should be consumed in moderation. Using a straw can also help minimize contact with teeth.

Yes, for some people, especially those with sensitive digestive systems or conditions like IBS, the carbon dioxide gas can cause bloating and gas. However, the effect varies widely among individuals, and many people experience no discomfort.

No, the carbonation in sparkling water does not harm bone density. This myth often stems from the high intake of phosphoric acid found in some colas, which has been linked to lower bone mineral density in some studies.

In some individuals, carbonated beverages can cause gas and pressure to build in the stomach, which may push stomach acid into the esophagus and trigger or worsen acid reflux. Others with GERD may find no effect or even experience relief, so it is highly dependent on the individual.

Yes, plain carbonated water is just as hydrating as still water. The addition of carbon dioxide gas does not interfere with the body's ability to absorb water, making it an excellent way to meet your daily hydration needs.

Yes, plain carbonated water is a much healthier alternative to sugary sodas. Unlike soda, it contains zero calories, no sugar, and none of the harmful additives that contribute to weight gain, tooth decay, and other health issues.

For some, carbonated water can improve digestion by helping to relieve constipation and stimulating the nerves that aid in swallowing. Its effect on digestion is highly individual, however.