For a long time, it's been thought that sufferers from acid reflux and related ailments such as gastro esophageal reflux disease (GERD) should avoid coffee because it could worsen reflux symptoms by causing the stomach to increase production of hydrochloric acid. Scientific studies have shown that some coffees may indeed cause acid reflux, but not all. It turns out that, much as it might seem counter-intuitive, dark-roasted coffees may not produce acid-reflux causing stomach acids, whereas milder coffees do. Understanding what it is about dark-roasted beans that inhibits acid production may prove a pivotal key toward one day eliminating any negative connection between coffee and acid reflux.
Darker roasts naturally contain a chemical, called N-methylpyridinium (NMP) that blocks the stomach from producing painful acids. This chemical isn't, however, found in milder roasts. This finding, presented in 2010 at the 239th National Meeting of the American Chemical Society, might help explain why an earlier study conducted by Stanford University found no relationship between coffee and acid reflux. Stanford's study in 2006 would have found no conclusive evidence that coffee and acid reflux are related—because not all coffees produce stomach acids. The Stanford study concluded that staying away from coffee wouldn't lessen symptoms of acid reflux, and that only dieting and elevating the head while sleeping could alleviate symptoms.
Oddly enough, there are good chances that many sufferers of acid reflux have turned to milder coffees in an attempt to quell heartburn. Rather than alleviating acid reflux, however, that intuition may have actually made symptoms worse. Drinking darker drip coffee or espresso drinks that contain NMP may be the answer to avoiding coffee-induced heartburn without having to give up the coffee.
By experimenting with mild roasts that contain NMP, researchers are seeking to change the relationship between mild coffee and acid reflux. If mild roasts can be brewed that contain NMP, future coffee lovers who cringe at the thought of dark roast might not have to change their tastes. For now, however, it appears that coffee and acid reflux can be avoided simply by sticking to darker beans.
Although some coffees may cause acid reflux, painful stomach acids are more often caused by overeating and poor sleeping habits. Straying from certain foods that can cause stomach acid; eating less and not right before sleep; and elevating the head during sleep are all proven methods of decreasing chronic acid reflux. Consulting a doctor is always recommended to get specific medical advice for how to treat a case of acid reflux.
