Soda is unlikely to help with indigestion, and in most cases it will make things worse. While the carbonation in soda can trigger a satisfying belch that temporarily relieves pressure in your stomach, the overall effect of soda on your digestive system tends to increase discomfort rather than reduce it.
Why Soda Feels Like It Helps
The relief people associate with soda comes down to one thing: belching. When you drink a carbonated beverage, the carbon dioxide dissolved in the liquid is released as gas once it hits the warm environment of your stomach. That expanding gas increases pressure against the upper portion of the stomach, which triggers your body’s natural belching reflex. The resulting burp releases trapped gas and can provide a brief sense of relief, especially if bloating or gas pressure was contributing to your discomfort.
This is a real physiological effect, and it explains why so many people reach for a can of ginger ale or cola when their stomach feels off. But the relief is short-lived, and the other ingredients in soda introduce new problems that often outweigh that momentary ease.
What Carbonation Does to Your Stomach
Carbonation on its own, without the sugar and other additives found in soda, has a more nuanced relationship with digestion. A clinical trial published in the European Journal of Gastroenterology and Hepatology tested carbonated water against plain tap water in people with functional dyspepsia, the medical term for chronic indigestion without a clear cause. After two weeks, people drinking carbonated water saw their symptom scores drop from about 7.9 to 5.4 on a standardized scale, while the tap water group showed no improvement at all. The carbonated water group also showed better gallbladder emptying, which plays a role in how efficiently your body digests fats.
That sounds promising, but there’s an important distinction: the study used plain carbonated water, not soda. No sugar, no caffeine, no artificial sweeteners, no phosphoric acid. Soda is a very different drink.
How Soda Can Worsen Acid Reflux
If your indigestion involves a burning sensation in your chest or throat, soda is one of the worst choices you can make. A study using high-resolution pressure sensors found that drinking just 200 milliliters of carbonated cola (less than a standard can) cut the pressure of the valve between the esophagus and stomach roughly in half, dropping from a median of 40.5 mmHg at baseline to 18.5 mmHg. That valve, called the lower esophageal sphincter, is the barrier that keeps stomach acid from washing back up into your throat.
On top of the pressure drop, the carbonated cola also dramatically increased the frequency of spontaneous valve relaxations, from a median of zero at baseline to 10.5 after drinking it. Each of those relaxations is an opportunity for acid to escape upward. This is why the National Institute of Diabetes and Digestive and Kidney Diseases specifically recommends avoiding carbonated drinks if you experience acid reflux or GERD. A 2021 review of multiple studies confirmed an association between regular carbonated beverage consumption and increased reflux risk.
The Sugar Problem
A 12-ounce can of regular soda contains around 39 grams of sugar, most of it as high-fructose corn syrup. When your digestive system doesn’t fully absorb fructose, the unabsorbed sugar ferments in your gut, producing gas, bloating, stomach pain, and sometimes diarrhea. This is fructose intolerance, and it’s far more common than most people realize. Even in people who absorb fructose normally, a large dose of sugar hitting an already irritated stomach can increase fermentation and worsen the gassy, bloated feeling that prompted you to reach for the soda in the first place.
Diet sodas sidestep the sugar issue but introduce artificial sweeteners, some of which (particularly sugar alcohols) can cause their own digestive symptoms, including bloating and loose stools. And diet sodas still contain the carbonation and acidity that weaken the esophageal valve.
Caffeine Adds Another Layer
Colas and some other sodas contain caffeine, which stimulates acid production in the stomach. If your indigestion is related to excess stomach acid, caffeine makes the situation worse. The NIDDK includes caffeinated beverages on its list of drinks to avoid for people dealing with acid reflux, alongside alcohol and citrus juices.
What Actually Helps Indigestion
Plain water is a safer starting point. It dilutes stomach acid without introducing carbonation, sugar, or caffeine. If you find that carbonation specifically helps your symptoms, plain sparkling water or mineral water gives you the gas-releasing effect without the drawbacks of soda. The clinical evidence supporting carbonated water for dyspepsia used exactly this type of drink.
Ginger tea has a longer track record for settling the stomach. Low-fat milk can temporarily buffer stomach acid, though full-fat milk may stimulate more acid production. Small, frequent meals rather than large ones reduce the volume of food your stomach has to process at once, which lowers the chance of that heavy, uncomfortable feeling.
If indigestion is a recurring problem rather than an occasional annoyance, the pattern matters more than any single drink choice. Eating too quickly, lying down soon after meals, wearing tight clothing around your midsection, and eating high-fat or spicy foods are all common triggers. Addressing those habits tends to produce more lasting relief than anything you pour into a glass.