How Coffee Affects Digestion and Gut Health

If you suffer from digestive disorders, you will want to learn how coffee & decaf may be aggravating your condition. Read below for an overview of the reasons why eliminating coffee from your diet may improve your symptoms.

Coffee increases incidence of GERD (gastro-esophageal reflux disease) & heartburn

Heartburn (pain beneath the breastbone), acid reflux and gastroesophageal reflux disease (GERD) occur when there is a regurgitation of acid or acid mixed with food from the stomach into the unprotected lining of the esophagus.

In chronic GERD, the sensitive tissues of the esophagus are frequently damaged, and people experience pain, dysphagia (difficulty swallowing), bleeding, and even choking. General symptoms of acid reflux, heartburn or GERD include chest pain, bleeding, esophageal stricture (narrowing or obstruction of the esophagus) or the pre-malignant Barrett’s esophagus.

Both decaffeinated and regular coffee are highly acidic and can increase the secretion of stomach acids.1 Decaffeinated coffee has been shown to increase acidity to a greater degree than either regular coffee or caffeine alone.2

Coffee has also been shown to decrease pressure in the lower esophageal sphincter (the ring of muscle between the esophagus and the stomach), suggesting that coffee can either cause or exacerbate reflux and heartburn in susceptible individuals.3 Both caffeinated and decaffeinated coffee aggravate reflux more than caffeine added to water, suggesting that components in coffee other than simply caffeine contribute to reflux.4 By kicking the caffeine habit, you can help decrease the painful symptoms of reflux disease and heartburn.

Contrary to popular belief, the type of roasting process used, the time of day coffee is consumed and whether or not it is combined with other foods does not affect the incidence of heartburn in susceptible persons.5

Coffee may aggravate ulcers

Ulcers are regions where the stomach lining has been destroyed by stomach acids or digestive fluids and enzymes. These can occur in the stomach or duodenum, the first part of the small intestine. When these sensitive areas of the body come into contact with digestive enzymes and acids, even small areas of damage can cause intense pain.

Doctors recommend that people with ulcers restrict not only caffeinated but also decaffeinated coffee intake to decrease pain associated with stomach ulcers.6 Coffee stimulates acid in the stomach and tends to speed up the process of stomach emptying, which may result in highly acidic stomach contents passing into the small intestine more rapidly than normal. This increases the risk of injury to the sensitive intestinal wall, heightening susceptibility for duodenal ulcers.7

The presence of the bacteria Helicobacter pylori in the stomach is a predisposing factor in ulcer development, but not everyone infected with H. pylori develops ulcers. A strong immune system may provide protection against the bacteria’s ability to colonize damaged areas of the stomach lining. Chronically increased levels of stress hormones, such as the glucocorticoids, (which happens under stress or as a result of frequent caffeine or coffee intake) can suppress the immune system.

Chronic glucocorticoid elevation also interferes with the reactions of antigen-specific cell-mediated immune responses to the presence of bacteria, viruses, fungi, some tumors and other invading organisms.8 Glucocorticoids can also cause cell death of a variety of lymphocytes, or white blood cells.9 This can create a situation in which the bacteria H. pylori can thrive in the stomach.

According to the American College of Gastroenterology, ulcers affect approximately 20 million Americans. Predisposing factors to ulcer formation include prolonged stress, skipping meals, being male, family history, cigarette smoking, coffee ingestion and presence of the bacteria Heliobacter pylori combined with a sensitive immune system.10

Coffee increases stress

The caffeine in coffee has been shown to increase the body’s production of stress hormones. These hormones, such as cortisol, are responsible for increased heart rate, increased blood pressure, and anxiety. Stress can worsen the symptoms of GERD, heartburn and inflammatory bowel conditions.

Chronic levels of increased stress hormones have also been shown to contribute to the overgrowth of the stomach bacteria H. pylori. Take better control of these conditions by getting off the coffee and stress roller coaster!

Caffeine interferes with your ability to feel good

GABA (Gamma-amino butyric acid) is a neurotransmitter naturally produced in the brain, nervous system, and the heart – it’s our “feel good” brain messenger that has an important role in mood and stress management. It is also shown to have a calming effect on the GI Tract, contributing to smooth functioning of the gastrointestinal musculature. Drinking caffeine may inhibit GABA’s ability to perform this calming function because caffeine interferes with the binding of GABA to GABA receptors11, as well as the activity of GABA-activated currents in nerve cell membranes.12

Caffeine also interferes with GABA’s role in stress management, which may worsen digestive health since chronic psychological stress is known to contribute to conditions such as acid reflux, GERD, irritable bowel syndrome, heartburn, esophageal reflux, and the development of ulcers. Don’t let coffee interfere with your natural calming mechanisms. Take steps to improve your stress by reducing your caffeine intake.

Works Cited


  1. Coffey, et al 1986
  2. Cohen and Booth 1975; Feldman, et al 1981
  3. Thomas, et al 1980; Boekema, et al 1999; Cohen 1980
  4. Wendl, et al 1994
  5. DiBaise 2003
  6. Marotta and Floch 1991
  7. Glatzel and Hackenberg 1967
  8. Dhabhar and McEwen 1997
  9. Wyllie 1980; Blewitt, et al 1983; Cidlowski, et al 1996
  10. Abu Farsakh 2002
  11. Roca, et al 1998; Ribeiro, J.A and Sebastiao, A.M. 2010; Cantu, et al 2003; Koek, et al 2003
  12. Li, et al 2004


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