Is it bad to drink coffee on an empty stomach?
Outside of the gut, caffeine from coffee is well known to increase heart rate and blood pressure. And if you drink it too close to bedtime, it can disrupt your sleep. But these changes are temporary, Dr. Cryer said.
Will increased stomach acid cause problems?
Drinking coffee on an empty stomach probably won’t cause any harm to your stomach, but theoretically it could cause heartburnsaid Dr. Barrett.
We know that coffee stimulates the production of stomach acid, but if you have food in your stomach or if you drink coffee with milk or cream, it will help create a buffer that helps neutralize that acid. So drinking coffee, especially black coffee, without a meal can lower stomach pH more than it would if you drank it with milk or with a meal, Dr. Barrett said.
Although a slightly lower pH is not a problem for the stomach lining, it could be a problem for the esophageal lining because it is much more susceptible to acid damage. Furthermore, several studies have shown that coffee can relax and open the sphincter that connects the esophagus to the stomach, which could hypothetically allow acid from the stomach to more easily burst up into the esophagus and cause unpleasant heartburn symptoms.
But even there the data is mixed. AND Overview of 15 studies from 2014 across Europe, Asia, and the United States found no link between coffee consumption and heartburn symptoms, while, in contrast, a 2020 study using data from more than 48,000 nurses higher risk of heartburn symptoms among coffee shops.
To understand how coffee might affect the esophagus, scientists are also studying a condition called Barrett’s esophagus, which occurs when the esophagus is damaged by chronic exposure to stomach acid, such as in people with long-term acid reflux problems. In this condition, the cells lining the esophagus turn into harder, stomach-like cells to protect themselves from the acid. These changes can increase the risk of esophageal cancer, especially if you have a family history of the disease or if you smoke. But encouragingly, a 2016 Study of Veterans in the United States did not find a similar relationship with coffee consumption. The authors concluded that for Barrett’s esophagus, avoiding coffee would probably not be helpful.
What should I do?
Practically speaking, as a gastroenterologist, I usually tell my patients to pay attention to their symptoms. If they’re constantly experiencing burning chest pain or a sour taste in their mouth after drinking coffee, they may want to cut back—or consider an antacid. Adding a little milk or cream or a small bite of food with your morning cup can also help. But if you don’t notice any symptoms, you’re probably someone who doesn’t experience significant reflux after coffee, and you can continue to drink it in peace.