There’s some extremely worrying news from a report on heartburn drugs that should cause you to think twice before reaching for them. Researchers at the Washington University School of Medicine found that popular heartburn drugs called proton pump inhibitors (PPIs) are associated with an increased risk of death.

Millions of people take PPIs in order to soothe their heartburn problems, but they may not be aware of the possibility that they are doing serious damage to their bodies in the process, as the report claims. PPIs work by neutralizing acid in the stomach, but scientists found that the drugs can increase the risk of death both compared to taking a different kind of acid suppressant, or nothing at all.

It’s not the first time concerns have been raised about PPIs. Previous research has linked them to kidney disease, pneumonia, and even higher rates of infection of the potentially deadly C difficile bug.

“Popular heartburn drugs called proton pump inhibitors (PPIs) have been linked to a variety of health problems, including serious kidney damage, bone fractures and dementia,” the university statement reads. “Now, a new study from Washington University School of Medicine in St. Louis shows that longtime use of the drugs also is associated with an increased risk of death.

“Millions of U.S. residents take proton pump inhibitors which are widely prescribed to treat heartburn, ulcers and other gastrointestinal problems. The drugs also are available over the counter under brand names that include Prevacid, Prilosec and Nexium.”