CThe findings showed that people taking these drugs called as proton pump inhibitors (PPIs) had a 50 per cent increased risk of dying over the next five years.
"People have the idea that PPIs are very safe because they are readily available, but there are real risks to taking these drugs, particularly for long periods of time," said Ziyad Al-Aly, Assistant Professor at the Washington University School of Medicine in St. Louis.
Further, for every 500 people taking PPIs for a year, there was one extra death that would not have otherwise occurred.
Given the millions of people who take PPIs regularly, this could translate into thousands of excess deaths every year, Al-Aly said.
PPIs have also been linked to a variety of health problems, including serious kidney damage, bone fractures and dementia, the researchers said.
For the study, published in the journal BMJ Open, the researchers examined medical records of some 275,000 users of PPIs and nearly 75,000 people who took another class of drugs -- known as H2 blockers -- to reduce stomach acid.
Both PPIs and H2 blockers are prescribed for serious medical conditions such as upper gastrointestinal tract bleeding, gastroesophageal reflux disease and esophageal cancer.
The results revealed a 25 per cent increased risk of death in the PPI group compared with the H2 blocker group.