Is Mineral Water Good for Acid Reflux?

Bicarbonate-rich mineral water can genuinely help with acid reflux, and the evidence is stronger than you might expect for something you can buy at a grocery store. A randomized, placebo-controlled trial found that drinking about 1.5 liters of bicarbonate-rich mineral water daily reduced heartburn in roughly 85% of participants over six weeks, compared to about 64% on placebo water. The benefit comes down to what is dissolved in the water, not just the water itself, and that distinction matters more than most people realize.

Why Bicarbonate Is the Key Ingredient

Not all mineral water is the same when it comes to reflux. The mineral that does the heavy lifting is bicarbonate, the same compound found in baking soda and many over-the-counter antacids. When bicarbonate reaches your stomach, it reacts with hydrochloric acid and neutralizes some of it, raising the pH. This is the same basic chemistry behind products like Rennie or Tums, just delivered in a glass of water instead of a chewable tablet.

The STOMACH STILL trial, a phase III randomized controlled study, compared a bicarbonate-rich mineral water against a placebo water that had been stripped of its minerals. Patients drank 1.5 liters per day for six weeks. In the mineral water group, about 85% experienced a meaningful reduction in heartburn symptoms. In the placebo group, about 64% improved. That gap held up statistically, with a number needed to treat of five, meaning for every five people who drank the mineral water, one additional person got relief beyond what plain water would have provided. The mineral water group also cut their use of rescue antacid tablets over the course of the trial. ¹

The researchers pointed out something practical: the neutralizing capacity of 1.5 liters of this mineral water per day was roughly equivalent to the recommended daily dose of a standard antacid. That is a useful comparison because it shows bicarbonate-rich mineral water is not a homeopathic wisp of an intervention. It delivers a pharmacologically meaningful amount of acid-neutralizing compound. ¹

More Than One Trial Backs This Up

An earlier open-label study using hydrogen carbonate-rich mineral water found similar results. After six weeks, the average number of heartburn episodes per week dropped by about five, and the duration of individual episodes shortened by about 19 minutes. Nearly 90% of patients experienced fewer heartburn episodes, and about 80% had shorter episodes. Patients and investigators both rated the water’s effectiveness highly. ²

A systematic review of clinical intervention studies on mineral water and heartburn found that the two studies using bicarbonate-rich mineral water both showed considerable reductions in both the frequency and duration of heartburn episodes. The mean frequency of heartburn episodes dropped from about seven per week to roughly two per week. The review noted that the comparative trials available still had methodological limitations, but the direction of the evidence was consistent. ³

So the evidence is real, but it is also limited. We are talking about a handful of trials, not dozens. The strongest trial was placebo-controlled and well-designed, but this is not the same depth of evidence behind proton pump inhibitors, which have been tested in hundreds of studies. For mild to moderate heartburn, bicarbonate mineral water looks like a reasonable, low-risk option. For severe or erosive reflux disease, it is unlikely to be sufficient on its own.

Alkaline Water and Pepsin

A related but distinct idea involves water at a higher pH. Acid reflux is not just about acid. Pepsin, a digestive enzyme produced exclusively by the stomach, plays a major role in the damage that reflux causes, particularly when reflux reaches the throat and airways. ⁴ Pepsin remains stable up to a pH of about 7, and it can reactivate if the environment becomes acidic again. ⁵

In a laboratory study, water at pH 8.8 irreversibly inactivated human pepsin. It also had a greater capacity to buffer hydrochloric acid than conventional water at a neutral pH. ⁶ This is an in vitro finding, meaning it was done in a test tube, not in a person’s stomach. Your stomach is a more complex environment than a beaker. But the result is interesting because it suggests a mechanism beyond simple acid buffering: high-pH water might permanently knock out one of the main agents of reflux damage.

A retrospective clinical study offered some support for this idea in practice. Patients with laryngopharyngeal reflux, where stomach contents reach the throat, were treated either with proton pump inhibitors or with a combination of alkaline water (pH above 8.0), a plant-based Mediterranean-style diet, and standard reflux precautions. About 63% of patients in the alkaline water and diet group achieved a clinically meaningful improvement, compared to about 54% on proton pump inhibitors alone. The alkaline water group actually showed a larger average reduction in symptom scores. ⁷

A word of caution on that study: the patients were not randomly assigned, and the alkaline water group was also following a plant-based diet and other lifestyle changes, so it is impossible to separate out how much the water itself contributed versus the dietary overhaul. Still, the results suggest that alkaline water as part of a broader anti-reflux strategy is at least comparable to medication for throat reflux symptoms.

The Carbonation Problem

Here is where things get complicated. Many bicarbonate-rich mineral waters are naturally carbonated, and carbonation has a specific downside for reflux. A study in healthy volunteers found that drinking a carbonated beverage roughly halved the resting pressure of the lower esophageal sphincter, the muscular valve between your esophagus and stomach. It also dramatically increased the frequency of transient relaxations of that sphincter, events that are the main mechanism by which reflux episodes happen. ⁸

So carbonated mineral water gives you two opposing forces at once: the bicarbonate is neutralizing acid, but the dissolved carbon dioxide is making it easier for whatever acid is left to splash up into your esophagus. For some people, the acid-neutralizing effect may win out. For others, especially those whose reflux is triggered by sphincter relaxation rather than excessive acid production, the carbonation could make things worse.

Carbonated water also increases feelings of fullness and gastric distension. ⁹ A fuller, more distended stomach is another trigger for sphincter relaxation and reflux episodes. If you tend to get reflux after large meals, adding a liter of bubbly water on top of that may not be doing you any favors, even if the minerals themselves are helpful.

The practical takeaway: if you can find a still (non-carbonated) bicarbonate-rich mineral water, you get the acid-neutralizing benefit without the sphincter-relaxing downside. Some brands sell both sparkling and still versions of the same water. If carbonated is all you can find, drinking it slowly and in smaller portions may minimize the gas-related effects.

When You Drink Matters Too

Timing your water intake is a factor people rarely consider, but it can make a meaningful difference. A study found that drinking 500 milliliters of water about an hour after a standard meal significantly decreased gastric motility and increased the occurrence of gastroesophageal reflux. It also raised levels of cholecystokinin, a hormone that slows stomach emptying. ¹⁰

This creates an apparent contradiction: the mineral content of the water should help, but the volume of water in an already-full stomach may provoke reflux. The answer depends on whether you are drinking a modest amount between meals or chugging a large glass right after dinner. Sipping mineral water between meals, or well before eating, lets you get the bicarbonate benefit without filling your stomach to the point where reflux becomes more likely. If your reflux tends to flare up postprandially (after meals), saving most of your mineral water intake for other parts of the day is probably wiser.

Not Every Mineral Water Will Help

Mineral waters vary enormously in composition. European regulations classify them by their dominant minerals: bicarbonate, sulfate, chloride, calcium, magnesium, sodium, and others. ¹¹ A water that is rich in bicarbonate is not the same product as one that is rich in calcium or sulfate, and the reflux evidence applies specifically to bicarbonate-rich varieties.

Calcium is an interesting case. Calcium carbonate is the active ingredient in many antacids, and some have suggested that the calcium in mineral water could contribute to heartburn relief by improving esophageal muscle tone and acid clearance. ¹² But there is a well-known flip side: oral calcium carbonate can stimulate the release of gastrin, a hormone that drives acid secretion. A classic study found that even small doses of calcium carbonate increased both gastrin levels and gastric acid output. This effect was specific to calcium acting on the stomach lining rather than through blood calcium levels. ¹³

This phenomenon, sometimes called “acid rebound,” is one reason doctors stopped recommending milk as a remedy for ulcers decades ago. A high-calcium mineral water could temporarily neutralize acid but then stimulate your stomach to produce more. If your mineral water is heavy on calcium and light on bicarbonate, the net effect on reflux is genuinely uncertain.

One preclinical and clinical study on a specific Italian mineral water (Uliveto, which contains bicarbonate along with calcium and other minerals) found that it actually increased acid and pepsinogen secretion as well as gastric emptying. The researchers attributed this to stimulation through gastrin receptors. ¹⁴ Faster gastric emptying might help reflux by clearing the stomach sooner, but increased acid secretion is clearly counterproductive. The mineral profile of a specific water shapes whether it helps or hurts, and blanket statements about “mineral water” being good or bad for reflux miss this complexity.

The Sodium Question

Many bicarbonate-rich mineral waters are also high in sodium, which raises an obvious concern for anyone watching their blood pressure. A liter and a half per day of a sodium-rich mineral water can deliver a substantial sodium load. But the form of sodium matters. A randomized controlled trial comparing sodium bicarbonate-rich water against a low-sodium control found that blood pressure did not differ between groups, even in participants who already had hypertension. Sodium excretion in urine went up, as you would expect, but the researchers found no association between that increased sodium output and blood pressure changes. ¹⁵

This finding aligns with older research showing that the blood-pressure-raising effect of sodium depends on the accompanying anion. Sodium chloride (table salt) raises blood pressure more than an equivalent amount of sodium bicarbonate. ¹⁶ So the sodium in bicarbonate mineral water is not nutritionally identical to the sodium in processed food or a salt shaker, at least when it comes to blood pressure. That said, these studies are relatively small and short-term. If you have kidney disease or are on a strict sodium-restricted diet, this is worth discussing with your doctor before committing to 1.5 liters a day.

How Mineral Water Compares to Medication

Proton pump inhibitors like omeprazole and esomeprazole are the most effective medical treatment for acid reflux, reducing stomach acid production at its source. Bicarbonate mineral water works by a completely different mechanism: it does not reduce acid production but rather neutralizes acid that has already been secreted. This means it is more comparable to an antacid than to a PPI.

For mild, occasional heartburn, the difference may not matter much. Many people use antacids and find them sufficient. The advantage of mineral water over a chewable tablet is that you are hydrating at the same time, you avoid aluminum or other additives found in some antacid formulations, and it can be integrated into your daily routine without feeling like you are taking medication. The disadvantage is the volume: you need to drink a fair amount of water to get the equivalent buffering capacity of a few antacid tablets, and as discussed above, the volume itself can provoke reflux if timed poorly.

For moderate to severe GERD with esophageal erosion, mineral water alone is unlikely to be adequate. The acid exposure in erosive disease is too persistent and too damaging to manage with buffering alone. PPIs reduce acid production around the clock, which mineral water cannot replicate. This is a supplement-versus-treatment distinction worth keeping straight: mineral water may be a useful addition to your routine, or a sufficient standalone option for mild symptoms, but it is not a replacement for prescription medication when the disease is serious.

Reading the Label

If you want to try mineral water for reflux, the label is your most important tool. Look for bicarbonate content, which is sometimes listed as “hydrogen carbonate” or “HCO₃.” The waters used in the clinical trials had bicarbonate concentrations above 1,000 mg per liter. Many widely available European brands (Gerolsteiner, Vichy Catalan, Apollinaris, Borjomi) fall in this range or above, but concentrations vary substantially. A mineral water with 200 mg/L of bicarbonate is going to do much less than one with 1,500 mg/L.

Check the sodium content if blood pressure is a concern for you, and note whether the water is naturally carbonated or still. If reflux is your primary issue, a still or lightly carbonated bicarbonate-rich water, sipped throughout the day and not concentrated around mealtimes, gives you the best chance of benefiting from the evidence we actually have. And if your symptoms persist or worsen despite trying these adjustments, that is the point at which a gastroenterologist’s evaluation makes more sense than experimenting with different brands of sparkling water.