Many contradictory studies about coffee have come out over the years. Some tout coffee’s health benefits, while others warn of its health risks. For example, coffee has benefits for those with type 2 diabetes and may reduce your risk for colon cancer and Parkinson's disease. On the other hand, coffee is often listed among the substances to avoid if you have problems with heartburn or other gastrointestinal, or GI, troubles.
Coffee or Caffeine?
Coffee isn’t the only drink implicated in problems with your stomach and intestines, because it isn’t the only one that contains caffeine. Chocolate and some types of tea and soda pop also contain caffeine. A 5-ounce cup of coffee has from 60 to 150 milligrams of caffeine. The same amount of tea has 40 to 80 milligrams and many 12-ounce sodas have between 55 and 65 milligrams. But it’s not just caffeine that may cause GI problems. Even decaffeinated coffee may contribute to your heartburn, indigestion or diarrhea.
Coffee and Heartburn
Caffeine is among the substances that may contribute to heartburn or acid reflux disease. Acid reflux occurs when the lower esophageal sphincter, or LES, a small muscle at the junction of your esophagus and stomach, is unable to stop the contents of your stomach from backing up. Many people experience this only occasionally as a burp and an acid taste in the mouth, but if it happens frequently, it can permanently damage the LES and the esophagus. Caffeine is implicated in this process because it has been thought to change the acid levels in the stomach, thus increasing the pressure on the LES. But an article published in the September 2009 issue of the journal “Gastroenterology & Hepatology” raises questions about the relationship between caffeine and acid reflux disease. The article reports that no studies have been able to demonstrate an association between coffee and relaxation of the esophageal sphincter or acid content.
Coffee and Ulcers
Researchers have also questioned the role of coffee in the development of gastrointestinal ulcers, also called peptic ulcers. These can occur in either the stomach or first section of the small intestine and are caused by a type of bacteria called H. pylori. While coffee doesn’t cause an ulcer, the acids in caffeinated foods often aggravate the condition.
Coffee and Other Intestinal Problems
Coffee, or more particularly, caffeine, tends to stimulate colon action, so may cause you to have diarrhea or just very soft stools. While for most people this is just an inconvenience, it can be debilitating for people with irritable bowel syndromes such as Crohn’s disease or ulcerative colitis.
Researchers have recently identified a chemical compound caused by a certain type of roasting process that inhibits acid production in coffee, according a report given at the American Chemical Society meeting in 2010. These low-acid coffees tend to be the darker roasts. If you love coffee, but it has an adverse effect on your GI tract, try drinking dark roasts, such as French roast, or some of the so-called “stomach-friendly” brands being marketed.
How Much Coffee is Too Much?
As with most foods, coffee is usually not a problem if you drink it in moderation. Many early studies that linked coffee with GI problems did not take into account the relationship between excessive ingestion of caffeinated drinks and high risk behaviors such as physical inactivity and tobacco use. According to MedlinePlus.com, most people can drink three 8-ounce cups of coffee per day without risk.
- Food and Drug Administration: Caffeine and Your Body
- Gastroenterology and Hepatology: The Effects of Lifestyle Modifications on GERD
- Drugs.com: Coming Soon: A Low-Heartburn Coffee?
- MedlinePlus: Caffeine in Diet
- Harvard Health Publications: Coffee Health Risks
- Children’s Hospital Boston: Stomach and Duodenal Ulcers