Why is carbonation not healthy? Unpacking the truth about fizzy drinks and your diet

October 10, 2025 •

4 min read

According to research from the USDA, annual per capita soft drink consumption can be very high in some regions, prompting the question: why is carbonation not healthy for everyone?. The answer is complex, as the health effects vary greatly depending on whether the beverage is plain sparkling water or a sugar-laden soda. While pure carbonation itself is relatively benign for most people, the real risks often stem from harmful additives.

Quick Summary

Carbonation introduces gas that can cause digestive issues like bloating and heartburn, but the primary health risks from fizzy drinks stem from added sugars, acids, and artificial sweeteners that harm dental health and contribute to chronic disease.

Key Points

Digestive Discomfort: Carbonation can cause gas, bloating, and belching, and may aggravate conditions like IBS and GERD in sensitive individuals.
Dental Risk: Added sugars and acids in many fizzy drinks are the primary culprits for severe enamel erosion and tooth decay, not pure carbonation.
Bone Health Myth: Pure carbonation does not harm bones; the misconception is linked to phosphoric acid in colas, which can interfere with calcium absorption.
Weight Gain: Sugary carbonated beverages are a major source of empty calories and are significantly associated with weight gain, obesity, and other chronic diseases.
Additive Dangers: Artificial sweeteners can cause digestive problems and alter gut bacteria, while sodium in some carbonated drinks can be an issue for individuals with high blood pressure.
Label Literacy: The healthiness of a fizzy drink depends entirely on its added ingredients, so it is crucial to read labels carefully to avoid sugar, sodium, and artificial compounds.
Healthier Alternative: Plain carbonated water is a healthy and hydrating option, often a better choice than fruit juice or soda for those seeking fizz.

Carbonation vs. The Cocktail of Additives

Many people confuse the effects of simple carbonation—the process of dissolving carbon dioxide ($CO_2$) gas in water—with the myriad of other ingredients found in popular soft drinks. When it comes to pure, plain sparkling water or seltzer, the health concerns are minimal for most individuals. The dissolved $CO_2$ creates a weak carbonic acid, which is responsible for the fizzy sensation. However, the vast majority of negative health impacts associated with "carbonated drinks" are not due to the bubbles themselves, but rather the added sugars, artificial sweeteners, sodium, phosphoric acid, and other chemicals that manufacturers include to enhance flavor.

Dental Health: The Erosion Equation

The biggest concern with carbonated beverages, even plain varieties, is their potential effect on dental enamel due to their acidity. Your tooth enamel begins to demineralize at a pH of 5.5. While plain carbonated water has a pH between 3 and 4, making it mildly acidic, research indicates its erosive effect is significantly less than that of sugary sodas. However, adding flavors or citric acid can dramatically lower the pH, increasing the risk. The real damage comes from soft drinks loaded with both sugar and acids. The sugar feeds bacteria in the mouth, which produce more acid, leading to a double-whammy of enamel erosion and tooth decay.

Digestive Discomfort and Sensitivity

For some people, particularly those with sensitive stomachs, the gas from carbonated drinks can cause uncomfortable digestive symptoms. When you swallow a fizzy drink, the $CO_2$ gas enters your stomach and can cause several issues:

Bloating and Gas: The gas expands as it warms to body temperature, leading to a sensation of fullness, bloating, and potential belching.
Aggravated GERD/IBS: Individuals with Gastroesophageal Reflux Disease (GERD) or Irritable Bowel Syndrome (IBS) may find their symptoms worsen with carbonated beverages. The increased pressure in the stomach can force stomach acid into the esophagus, triggering heartburn.

Debunking the Bone Health Myth

One of the most persistent myths is that carbonation leaches calcium from bones, leading to osteoporosis. Scientific research has largely debunked this. Studies have found that while cola consumption is linked to lower bone mineral density in women, this effect is primarily attributed to the phosphoric acid found in cola, not the carbonation itself. Phosphoric acid can increase the loss of calcium through the kidneys. Importantly, plain sparkling water generally does not contain phosphoric acid and has no significant negative impact on bone health. In fact, some mineral waters containing calcium and magnesium may even support bone health.

The Link to Weight Management

While the carbonation itself is calorie-free, the most common carbonated beverages are laden with sugar, a major contributor to obesity and related chronic conditions. Replacing these sugary drinks with plain carbonated water is a positive step toward reducing calorie intake and aiding weight management. However, some research, including an animal study, has explored a less definitive link between carbonation and appetite.

Comparison: Plain Sparkling Water vs. Sugary Soda


Feature	Plain Sparkling Water	Sugary Soda
Calories	Zero	High, often over 100 per serving
Added Sugar	None	High-fructose corn syrup or sucrose
Acidity (pH)	Mildly acidic (3-4), varies	Highly acidic (1.8-3.5) due to various acids
Dental Impact	Minimal erosion risk, especially with proper habits	High risk of severe enamel erosion and decay
Digestive Impact	Can cause bloating, gas, or heartburn in sensitive individuals	Can cause bloating and aggravate reflux; caffeine can irritate
Bone Impact	No negative impact, some minerals may help	Phosphoric acid in colas linked to lower bone density in women

Making Healthier Choices

Making informed choices about carbonated beverages is key. For those who enjoy the fizz but want to avoid the drawbacks, consider these steps:

Opt for Plain: The healthiest option is always plain seltzer or sparkling mineral water with no added sugar, artificial sweeteners, or flavorings.
Read Labels: Be diligent about reading nutrition labels, especially on flavored sparkling waters. The term "natural flavors" doesn't guarantee a health benefit.
Infuse Naturally: Add slices of fresh lemon, lime, cucumber, or berries to plain seltzer for flavor without the added sugars or acids.
Protect Your Teeth: Drinking carbonated beverages with meals or using a straw can help minimize contact with tooth enamel. Rinsing your mouth with still water afterward is also helpful.
Homemade Fizz: Using a home carbonation machine allows you to add fizz to tap water, which often contains fluoride—an important mineral for dental health.

Conclusion

While the simple process of carbonation is not inherently unhealthy for most people, the negative health reputation of fizzy drinks is well-deserved due to the common cocktail of additives. The dangers posed by excessive sugar, enamel-eroding acids, and potentially harmful artificial sweeteners far outweigh any concerns about the bubbles themselves. By understanding the distinction between plain carbonated water and its sugary counterparts, and by choosing wisely, you can enjoy the fizz without compromising your nutritional diet or long-term health. Moderation and label-reading are the most effective strategies for enjoying carbonated beverages in a healthy way.

For further reading on how sugar impacts overall health, visit the Centers for Disease Control and Prevention (CDC) website.

Frequently Asked Questions

Plain sparkling water is mildly acidic due to the carbonic acid from the dissolved $CO_2$, but its erosive effect on enamel is minimal, especially compared to sugary sodas. It's significantly less harmful than soft drinks with added sugars and acids.

No, carbonation itself does not cause bone loss. The myth stems from studies linking cola drinks, which contain phosphoric acid, to lower bone mineral density in women. Plain carbonated water does not have this effect.

Carbonated drinks contain dissolved carbon dioxide gas, which becomes gas in your stomach. This can cause your stomach to expand and lead to bloating, burping, and other digestive discomfort.

Plain carbonated water, with no added sugars or calories, is not linked to weight gain. However, sugary carbonated beverages are a major contributor to obesity due to high calorie and sugar content.

For some individuals, especially those with GERD, the increased pressure from the gas in carbonated drinks can push stomach acid back into the esophagus, leading to or worsening heartburn.

Artificial sweeteners can have their own set of health concerns. They can cause digestive issues like bloating and diarrhea in some individuals and may have long-term health implications that are still being studied.

The healthiest choice is plain, unsweetened seltzer or sparkling mineral water. For added flavor, infuse it with fresh fruit slices or herbs instead of relying on commercially flavored varieties.