Question: I have been told that drinking coffee on an empty stomach can damage the stomach lining. It’s true?
For many people, enjoying a fresh cup of coffee first thing in the morning is the non-negotiable way to start the day. But the idea that taking a sip without eating could harm the gut (or contribute to other ailments like bloating, acne, hair loss, anxiety, thyroid problems, or painful periods, as some social media users claim) has spread. attracted as much popularity as disbelief.
According to Kim Barrett, professor of Membrane Physiology and Biology at the University of California, Davis, School of Medicine and a member of the board of directors of the American Gastroenterological Association, researchers have studied the benefits since the 1970s. and damages of coffee consumption, especially in relation to the stomach. Luckily, this one can handle all sorts of irritants, including coffee.
“The stomach has many ways to protect itself,” Barrett said. For example, it secretes a thick mucus that creates a powerful protective layer between your stomach lining and what you eat. That layer also protects the stomach from its own natural acidic environment, which is needed to break down food, he explained.
You would have to consume a very aggressive substance “to break down the defenses of the stomach, since it is constantly in a very adverse and harmful environment,” Barret said. “This is how the stomach does its job.”
How does coffee affect the stomach?
It is well known that irritants such as alcohol, tobacco smoke and nonsteroidal anti-inflammatory drugs such as ibuprofen (Advil, Motrin) or naproxen (Aleve) disrupt the stomach’s natural defense mechanisms and damage its lining, Byron said. Cryer, chief of internal medicine at Baylor University Medical Center in Dallas.
His research lab specializes in understanding how different drugs and other chemicals can damage the stomach and small intestine. Although certain irritants can make the stomach more vulnerable to acid formation and ulcers, several large-scale studies have revealed that this is not the case with coffee. For example, a 2013 study involving more than 8,000 people living in Japan found no significant relationship between coffee consumption and the formation of stomach or intestinal ulcers, even among those who drank three cups. or more per day.
“Coffee, even concentrated, is not likely to cause stomach injury,” Cryer said. “And much less in the usual doses of common drinks.”
However, coffee does have an effect on the digestive system: it can speed up the colon and promote intestinal transit, as well as increasing the production of acid in the stomach.
Outside of this organ, it’s well known that the caffeine in coffee increases heart rate and blood pressure, and if you drink it too close to bedtime, it can disrupt sleep, but these changes are temporary, Cryer said.
Can increased stomach acid cause any problems?
Drinking coffee on an empty stomach is unlikely to cause stomach damage, but could theoretically cause heartburn, Barrett said.
We know that coffee triggers the production of stomach acid, but if you have food in your stomach or if you drink your coffee with milk or cream, that will act as a buffer that helps neutralize that acid. So drinking coffee, especially black, without food can lower stomach pH more than it would if you had it with milk or food, Barrett said.
Although a slightly lower pH is not a problem for the stomach lining, it could be a problem for the lining of the esophagus, as it is much more vulnerable to acid damage. Additionally, some studies have shown that coffee can relax and open the sphincter that connects the esophagus to the stomach, which in theory could allow stomach acid to splash up the esophagus more easily and cause unpleasant heartburn symptoms.
But even in this case, the data is contradictory. A 2014 review of 15 studies conducted in Europe, Asia, and the United States found no relationship between coffee consumption and heartburn symptoms, while a 2020 study using data from more than 48,000 nurses found an increased risk of heartburn symptoms among coffee drinkers.
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, as occurs in people with long-term acid reflux problems. . In this case, the cells that line the esophagus change into tougher cells, similar to those in the stomach, to protect themselves from the acid. These changes can increase the risk of esophageal cancer, especially if you have a family history of this disease or if you smoke. But to our reassurance, a 2016 study of US veterans found no similar relationship with coffee consumption. The authors concluded that for Barrett’s esophagus, avoiding coffee would probably not be helpful.
Then what should I do?
In practice, as a gastroenterologist, I usually advise my patients to take their symptoms into account. If you notice a constant burning sensation in your chest or a sour taste in your mouth after drinking coffee, you may want to cut back on the amount you drink or consider taking an antacid. Adding a splash of milk or cream or a bite of food with your morning cup can also help, but if you don’t notice any symptoms, you may be someone who doesn’t experience major reflux after coffee and can safely continue to drink it.
Cryer often drinks lattes or cappuccinos, saying steamed milk or milk foam reduces acidity, adding that drinking coffee generally has many health benefits, associated with longevity, lower risk cardiovascular disease and protection against many types of cancer, such as liver, prostate, breast and colorectal.
“There is much more evidence for the benefits of coffee than for its harmful effects,” Cryer concluded, something worth keeping in mind while viewing negative content about coffee consumption on social media.
