Aerated drinks are beverages infused with carbon dioxide gas under pressure, creating the fizz and bubbles you feel when you take a sip. The term covers a wide range of drinks, from colas and lemon-lime sodas to sparkling water, tonic water, and even beer. “Aerated” simply refers to the process of dissolving gas into liquid, and in most of the world, these drinks go by other names: carbonated beverages, fizzy drinks, soft drinks, or sparkling drinks.
How Carbonation Works
Carbon dioxide doesn’t dissolve easily in water at normal atmospheric pressure. To get it into a beverage, manufacturers force CO2 into the liquid at elevated pressures, typically between 15 and 40 PSI depending on the product and desired fizz level. At these pressures, the gas stays dissolved and the liquid looks still inside a sealed bottle or can.
The moment you open the container, the pressure drops to normal atmospheric levels. The dissolved CO2 rapidly escapes from the liquid, forming the bubbles and fizz you see rushing to the surface. This release of gas is called effervescence. It’s also what gives carbonated drinks their slight tingling or biting sensation on your tongue, since a small amount of the CO2 reacts with water to form carbonic acid.
Not all carbonation is artificial. Some beverages become naturally fizzy through fermentation, where yeast produces CO2 as a byproduct. This is how traditional beers, champagne, and certain kombucha drinks get their bubbles without an industrial carbonation step.
Types of Aerated Drinks
The category is broader than most people realize. Here are the main types:
- Sodas and soft drinks: Sweetened, flavored, and heavily carbonated. Colas, lemon-lime sodas, and orange sodas fall here.
- Sparkling water (seltzer): Plain water with added CO2 and nothing else. No sodium, no added minerals. Brands like LaCroix are examples, though their bubbles tend to be lighter and dissipate faster.
- Club soda: Carbonated water with added minerals like sodium and potassium, giving it a slightly salty taste and often firmer, longer-lasting bubbles.
- Sparkling mineral water: Water sourced from natural springs that contains naturally occurring minerals. Brands like San Pellegrino and Topo Chico have moderate sodium and characteristically lively carbonation.
- Tonic water: Carbonated water sweetened and flavored with quinine, which gives it a bitter taste. Despite the name, tonic water contains sugar comparable to many sodas.
- Energy drinks and flavored sparkling beverages: Carbonated drinks with added caffeine, vitamins, or fruit flavoring.
The practical differences between sparkling water, club soda, and mineral water come down to sodium content and bubble quality. Club soda has the most added sodium, plain seltzer has none, and mineral waters fall somewhere in between depending on their source.
What’s Inside a Typical Soda
Water makes up the vast majority of any aerated drink. Beyond that, a standard sweetened soft drink contains about 8 to 12 percent sweetener by weight, 0.3 to 0.6 percent dissolved carbon dioxide, and small amounts of acids, flavorings, colorings, and preservatives.
The sweetener in regular sodas is usually sucrose (table sugar), glucose, or fructose, often in the form of high-fructose corn syrup. Diet versions replace these with intense sweeteners like aspartame, acesulfame potassium, sucralose, or saccharin, which provide sweetness at a fraction of the quantity.
Acids play a bigger role than most people expect. Citric acid is the most common, used across many flavors to sharpen taste and enhance aroma. Cola-type drinks rely on phosphoric acid instead, which gives them their distinctive sharp, tangy profile. These acids are a major reason aerated drinks are so acidic, often reaching a pH as low as 2.5. For reference, pure water has a pH of 7.
Effects on Teeth
Tooth enamel begins to dissolve at a pH of about 5.5. Most commercial carbonated drinks sit well below that threshold, meaning every sip temporarily bathes your teeth in an acidic environment. The acidity comes not just from carbonic acid (formed when CO2 dissolves in water) but also from the citric acid, phosphoric acid, or tartaric acid added for flavor.
Lab studies consistently show signs of enamel erosion after as little as 60 minutes of exposure to carbonated soft drinks. In real life, you’re not holding soda against your teeth for an hour straight, but frequent sipping throughout the day extends that contact time significantly. Plain sparkling water is far less damaging because it lacks the added acids and sugars, though it’s still slightly more acidic than still water.
Sugar, Weight, and Metabolic Risk
The biggest health concern with aerated drinks isn’t the bubbles. It’s the sugar. A standard 12-ounce can of soda contains roughly 35 to 40 grams of sugar, about 9 teaspoons. Because liquid calories don’t trigger the same fullness signals as solid food, it’s easy to consume a large amount of sugar from drinks without eating less of anything else.
A meta-analysis pooling data from over 310,000 participants found that people with the highest intake of sugar-sweetened beverages had a 26 percent greater risk of developing type 2 diabetes compared to those who drank the least. A separate analysis of more than 19,000 participants found a 20 percent increased risk of metabolic syndrome, a cluster of conditions including high blood sugar, excess abdominal fat, and abnormal cholesterol levels that raises your risk for heart disease. These associations held even after accounting for other dietary and lifestyle factors, suggesting the drinks themselves contribute to the problem rather than simply being a marker of an unhealthy diet.
Effects on Bones
Cola drinks specifically have drawn attention for a possible link to lower bone density. The proposed mechanism involves phosphoric acid, which is found in colas but not in most other carbonated drinks. A diet high in phosphorus but low in calcium can stimulate parathyroid hormone, which pulls calcium from bones to maintain blood levels. High phosphorus intake may also interfere with the body’s ability to activate vitamin D, further disrupting calcium balance.
This concern applies mainly to colas, not sparkling water or other carbonated beverages that don’t contain phosphoric acid. The risk also increases when soda displaces milk or other calcium-rich drinks from the diet, which is common in adolescents and young adults.
Diet Versions and Artificial Sweeteners
Diet aerated drinks replace sugar with intense sweeteners that provide virtually zero calories. The most widely used is aspartame, which the WHO’s Joint Expert Committee on Food Additives reviewed in 2023 and reaffirmed as safe at intakes up to 40 milligrams per kilogram of body weight per day. For a 150-pound person, that works out to roughly 12 to 14 cans of diet soda daily, far more than anyone typically drinks.
Switching from regular to diet soda eliminates the sugar and calorie load, which removes the most clearly harmful ingredient. However, diet drinks still contain the same acids that affect tooth enamel, and colas still contain phosphoric acid regardless of whether they’re sweetened with sugar or a sugar substitute.
Carbonation and Digestion
Many people notice bloating or a feeling of fullness after drinking something fizzy. This happens because the CO2 released from the drink expands in your stomach, stretching the upper portion. A controlled study comparing carbonated water to still water found that carbonation didn’t change how quickly the stomach emptied overall, but it did change where food sat inside the stomach. With carbonated water, a significantly greater proportion of both solid food and liquid was retained in the upper stomach (74 percent of solids versus 56 percent with still water), likely due to the distension caused by gas.
This redistribution explains why a fizzy drink can make you feel fuller temporarily without actually slowing digestion. For people prone to acid reflux, that extra pressure in the upper stomach can push contents upward and worsen symptoms. For others, the effect is harmless and short-lived.
Plain Sparkling Water vs. Sweetened Sodas
It’s worth separating the effects of carbonation itself from the effects of what’s dissolved alongside it. Plain sparkling water, with no added sugar, acids, or phosphoric acid, carries almost none of the risks associated with soft drinks. It hydrates just as well as still water, has a mildly acidic pH that poses minimal threat to enamel, and contains no calories.
The health concerns that come up in research are driven almost entirely by the sugar, the added acids, and in the case of colas, the phosphoric acid. If you enjoy the sensation of fizzy drinks but want to avoid the downsides, unsweetened sparkling water or mineral water gives you the bubbles without the baggage.