Does Coffee Cause Acid Reflux or Not?

Some people find that coffee gives them acid reflux or heartburn.

Others swear it has no effect at all.

To find out who is right, a new study published on the Preprints platform conducted a large review of dozens of previous studies from across the world.

And the answer will surprise you (whether you believe coffee is good or bad for acid reflux).

The researchers looked at human and animal studies on coffee and upper gastrointestinal issues.

They evaluated the findings using nine specific scientific criteria known as the Bradford Hill principles.

These include looking at whether coffee actually causes a condition or if it’s just associated with it, whether higher intake means worse symptoms, whether it works through a biological mechanism, and more.

After all this effort, the evidence remains completely muddled:

1. Mechanisms exist for both harmful and protective effects. For example, coffee increases acid secretion, but also contains antioxidants that can reduce inflammation and cancer risk.

2. Many studies contradict each other. For example, coffee was linked to a 49% lower risk of esophageal cancer in one study, but to a 24% increased risk of gastric cancer in another.

3. The lack of consistent findings across different studies weakens the case for causality. Some studies showed strong links (e.g., UK Biobank showed consistent risk increases for acid reflux and digestive cancers), while others (e.g., FinnGen) did not replicate these results.

4. In most studies, coffee was linked to multiple conditions (e.g., irritable bowel syndrome, acid reflux, gastric and esophageal cancers), not just one. Lack of a unique link to one specific disease also weakens the case that coffee causes acid reflux.

5. The strongest associations between coffee and acid reflux were found in women, overweight individuals, fasting reflux patients, and those genetically predisposed to heartburn.

6. In acid reflux patients, coffee increased symptoms only when consumed during fasting. After meals, it didn’t have the same effect.

7. Coffee seems to affect people differently. Some people are more sensitive to caffeine due to body weight, gender, or genetics.

8. Certain brewing methods and whether the coffee is caffeinated or not also seem to matter.

The reality is that research currently cannot say for sure. There’s quite a lot of evidence that coffee drinkers are more likely to have acid reflux, but it’s definitely not a strong enough association to be considered causal. It might work through other conditions.

And try to drink your coffee after meals instead of on an empty stomach (like early morning).

But why not eliminate your acid reflux completely?

Thousands of readers have done that using the three common ingredients (explained here)—you most likely already have them sitting in your kitchen…