Acid reflux, heartburn and the chronic gastroesophageal reflux disease (commonly known as GERD) are uncomfortable conditions affecting millions of people. In the U.S., statistics reveal that 60 million Americans experience acid indigestion monthly. Fifteen million people experience acid indigestion daily. The healthcare costs associated with these exceed $40 billion annually.
What are acid reflux and GERD?
In heartburn (pain beneath the breastbone), acid reflux and gastroesophageal reflux disease (GERD), there 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. A relaxation or weakening of the lower esophageal sphincter (LES), the ring of muscle between the esophagus and the stomach, can contribute to these conditions.
Coffee and caffeine use contribute to increasing reflux in susceptible persons
Coffee and caffeine are two substances known to aggravate these painful disturbances of the upper gastrointestinal tract; they create more problems than simply drinking water. (Terry, et al, 2000), (Feldman and Barnett, 1995) Drinking coffee triggers reflux more often than caffeine added to water, suggesting that components other than simply caffeine contribute to reflux. (Wendl, et al, 1994) Some of the things that do not further affect the incidence of heartburn in susceptible persons include: the type of roasting process used, the time of day the coffee is consumed or whether it is combined with other foods. (DiBaise, 2003)
Coffee Decreases Pressure in the Lower Esophageal Sphincter
Coffee has been shown to decrease pressure in the lower esophageal sphincter; this suggests that coffee can either cause or exacerbate heartburn in susceptible individuals. (Thomas, et al, 1980) (Boekema, et al, 1999) (Cohen, 1980)
Coffee, Acidity and Heartburn
Highly acidic coffee can stimulate the hypersecretion of gastric acids. (Coffey, et al, 1986) (Borger, et al, 1976) Decaffeinated coffee has been shown to increase acidity to a greater degree than either regular coffee or caffeine alone, and to a greater degree than many other foods. (Cohen and Booth, 1975) (Feldman, et al, 1981)
Coffee, Stress and Heartburn
Both anxiety and sustained stress are associated with exacerbation of heartburn and esophageal reflux. (Naliboff, et al, 2004) Caffeine in coffee elevates the stress hormones cortisol, epinephrine (also known as adrenaline) and norepinephrine. (Robertson, et al, 1978) (Lane, et al, 1990) (Lane, 1994) (Kerr, et al, 1993) These hormones mediate the body’s stress response, or state of "high alert," during which heart rate and blood pressure increase and blood and resources are diverted from the immune and digestive systems. This diversion can inhibit digestion and increase indigestion.
Coffee interferes with the Relaxing effect of GABA
GABA (Gamma-aminobutyric acid) is a neurotransmitter produced in the brain and nervous system as well as the digestive system. GABA is important role in mood and stress management and it has a calming effect on the GI tract.
Caffeine has been found to interfere with binding of GABA to GABA receptors, preventing the neurotransmitter from performing its calming function.26 In addition to its direct effect on the GI tract, GABA’s role in stress management is also compromised in the presence of caffeine, which is significant since psychological stress is shown to be an exacerbating factor in heartburn. (Naliboff, et al, 2004)
Since caffeine interferes with the relaxing effect of GABA receptors, it may impact people with reflux arising from lower esophageal sphincter pressure. (Cantu, et al, 2003) (Koek, et al, 2003)
References (by alphabetical order)
Boekema, P.J., Samsom, M., van Berge Henegouwen, G.P. and Smout, A.J. 1999. Coffee and Gastrointestinal function: facts and fiction. A Review. Scandinavian Journal of Gastroenterology Supplement. 230: 35-9.
Borger HW, Schafmayer A, Arnold R, Becker HD, Creutzfeldt W. 1976. The influence of coffee and caffeine on gastrin and acid secretion in man. Deutsche medizinische Wochenschrift. 101(12):455-7.
Coffey, R.J., Go, V.L., Zinsmeister, A.R. and DiMagno, E.P. 1986. The acute effects of coffee and caffeine on human interdigestive exocrine pancreatic secretion. Pancreas. 1(1):55-61.
Cohen, S. 1980. Pathogenesis of coffee-induced gastrointestinal symptoms. New England Journal of Medicine. 303(3):122-4.
Cohen, S. and Booth, G.H. Jr. 1975. Gastric acid secretion and lower-esophageal-sphincter pressure in response to coffee and caffeine. New England Journal of Medicine. 293(18):897-9.
DiBaise, JK. 2003. A randomized, double-blind comparison of two different coffee-roasting processes on development of heartburn and dyspepsia in coffee-sensitive individuals.Digestive Diseases and Sciences. 48(4):652-6.
Feldman EJ, Isenberg JI, Grossman MI. 1981. Gastric acid and gastrin response to decaffeinated coffee and a peptone meal. JAMA. 246(3):248-50.
Feldman, M. and Barnett, C. 1995. Relationships between the acidity and osmolality of Popular Beverages and reported Postprandial Heartburn. Gastroenterology. 108(1): 125-31.
Kerr, D., Sherwin, R.S., Pavalkis, F., Fayad, P.B., Sikorski, L., Rife, F., Tamborlane, W.V. and During, M.J. 1993. Effect of caffeine on the recognition of and responses to hypoglycemia in humans. Annals of Internal Medicine. 119(8):799-804.
Lane, J.D. 1994. Neuroendrocine Responses to Caffeine in the Work Environment. Psychosomatic Medicine. 546:267-70.
Lane, J.D., Adcock, R.A., Williams, R.B. and C.M. Kuhn. 1990. Caffeine effects on cardiovascular and neuroendocrine responses to acute psychosocial stress and their relationship to level of habitual caffeine consumption. Psychosomatic Medicine. 52(3):320-36.
Naliboff BD, Mayer M, Fass R, Fitzgerald LZ, Chang L, Bolus R, Mayer EA. 2004. The effect of life stress on symptoms of heartburn. Psychosomatic Medicine. 66(3):426-34.
Robertson, D., Frolich, J.C., Carr, R.K., Watson, J.T., Hollifield, J.W., Shand, D.G. and J.A. Oates. 1978. Effects of caffeine on plasma renin activity, catecholamines and blood pressure. New England Journal of Medicine. 298(4):181-6.
Terry P, Lagergren J, Wolk A, Nyren O. 2000. Reflux-inducing dietary factors and risk of adenocarcinoma of the esophagus and gastric cardia. Nutrition and Cancer. 38(2): 186-91.
Thomas, F.B., Steinbaugh, J.T., Fromkes, J.J., Mekhjian, H.S., and Caldwell, J.H. 1980. Inhibitory effect of coffee on lower esophageal sphincter pressure. Gastroenterology, Dec; 79(6): 1262-6.
Wendl, B., Pfeiffer, A., Pehl, C., Schmidt, T. and Kaess, H. 1994. Effect of decaffeination of coffee or tea on gastro-oesophageal reflux. Alimentary pharmacology & therapeutics. 8(3):283-7.