Does gastroesophageal reflux disease (GERD) affect a breath alcohol result?

Gastroesophageal reflux disease (GERD) is a condition whereby the muscle that connects the esophagus and stomach doesn't function properly. Symptoms of GERD can include heartburn, acid reflux, indigestion, regurgitation, and a resulting acidic taste in the mouth.

In a person with GERD, trigger foods and drinks cause the contents of the stomach to return back up into the esophagus and then into the mouth. The question of whether GERD can affect an alcohol breath result has been raised in court cases against driving after drinking or driving while intoxicated.

Lawyers' Perspectives On Alcohol Breath Testing And GERD

Remember that the symptoms of GERD can cause the contents of the stomach to return to the mouth. This means that alcohol from the stomach could move upwards and back into the mouth in GERD sufferers, creating "mouth alcohol."

There is an argument that appears to be widely distributed by law firms. This is based on the theory that mouth alcohol present in GERD sufferers can lead to a breathalyzer showing a higher alcohol level than is actually present in the blood. This supposedly leads to many GERD sufferers being wrongly arrested for a high result on an alcohol breath test, after intakes of alcohol that they would not have expected to show up as being "over the limit."

Even if the required period of at least 15 minutes between consuming alcohol and being breath tested is adhered to, the argument is that "mouth alcohol" can be produced by GERD sufferers during this time. This is as a result of belching or other movements that are forcing alcohol from the stomach back up into the mouth. The theory is that this gives a falsely high alcohol concentration reading.

But how much of this theory is based on science?

What The Scientific Studies Say

There are few studies that have been done on the effects of GERD on breath alcohol results. Those that have been done seem to be on small population sizes, but nonetheless on subjects with diagnosed GERD.

One study looked at five male subjects and five female subjects, all suffering from severe GERD. Regular blood alcohol and breath alcohol readings were taken after the subjects received the same dose of alcohol (based on the person's body weight). As part of this study, an attempt was made to provoke GERD symptoms in the subjects. During the absorption phase, the alcohol breath content tended to be the same as or higher than the blood alcohol content. After this phase the blood alcohol content was always higher than thebreath alcohol content, even in those experiencing GERD symptoms. From this study, the authors concluded that the chance of alcohol erupting into the mouth as a result of acid reflux, and falsely increasing the results on a breath test is highly improbable.

Another study reported similar findings. The breath alcohol content in GERD sufferers was only found to be higher than the blood alcohol content shortly after drinking ceased. The authors concluded that GERD related alcohol leakage from the stomach into the mouth is an irrelevant source of potential error in breath testing.

Based on the findings from these studies there does not appear to be sufficient evidence that GERD symptoms will lead to a falsely high reading in an alcohol breath test (despite the approach some lawyers are taking).