Acid Levels in Caffeinated Vs. Decaf Coffee

Many people wonder if coffee is bad for them. Some switch to decaf in an attempt at healthier living. Studies indicate that a moderate amount of caffeine is safe for most people. But for certain health conditions, like acid reflux, switching to decaf might be a good decision, because decaf lacks caffeine and may, in some cases, contain less acid than regular coffee does.

Cup of coffee (Image: LennartK/iStock/Getty Images)

Stomach Acid

Coffee both contains acid and creates acid. There's the amount of acid in the brew itself, but there's also the acid your stomach produces as a result of drinking the coffee. In the latter case, caffeine is a culprit, as it makes your stomach generate more acid. But other components of coffee also stimulate stomach acid. People who suffer from acid reflux, a condition in which stomach contents seep up the esophagus, may want to reconsider drinking coffee at all.

Differing Studies

A study at Munich's Hospital Bogenhausen, as reported in the June 1997 issue of the "Alimentary Pharmacology & Therapeutics Journal," found that patients experienced less gastroesophageal reflux when drinking decaffeinated coffee. But some studies have had the opposite results. Some experts say it depends on the type of bean from which the coffee is made.

Acid and Flavor

Most coffee is made from Arabica or Robusta beans. Robusta beans are less expensive and considered less desirable by coffee manufacturers. Often they're mixed with Arabica for a better tasting blend. Decaffeinated coffees are often heavy on the Robusta content. In addition to the mix of Robusta versus Arabica, the flavor of the coffee is heavily influenced by the organic acids in the bean, including quinic, malic, acetic, citric and formic acids. Acid content is linked to the maturity of the coffee fruit when picked, and the length of roasting time. Longer roasting decreases the acid content. A study by Dionex, part of Thermo Fisher Scientific, separated the anions, or negatively charged ions, in regular and decaffeinated coffee. They found higher levels of all acids in regular than in decaf coffee.

Doses of Caffeine

Even people who are not sensitive to the acid in coffee may be sensitive to caffeine. According to MedlinePlus, most people can consume up to 200 milligrams of caffeine daily without ill effects. But even low doses can cause irritability, insomnia and stomach pains in more sensitive folks. Those who are extra-susceptible to caffeine should keep in mind that even decaf has some caffeine. While an 8-ounce cup of brewed coffee contains about 75 milligrams of caffeine, decaf has between 8 and 14 milligrams.