Next time you reach for that bottle of antacids, think hard. If you’ve been doing it for a long time with little to show for it, you might want to reconsider your strategy.

Researchers at City of Hope and the Keck School of Medicine of the University of Southern California recently found that people who soothe their sour stomachs by swallowing over-the-counter antacids regularly for years appear to be at greater risk for a type of esophageal cancer.

Leslie Bernstein (Photo by Walter Urie)

“These over-the-counter medications suppress symptoms but do not influence the underlying disease process,” said Leslie Bernstein, Ph.D., chief of the Division of Cancer Etiology in City of Hope’s Department of Population Sciences. “It may be that people are using these medications to mask symptoms of precancerous conditions, without going to see a physician, permitting cancer to develop.”

Although esophageal adenocarcinoma is relatively rare, the cancer’s incidence has jumped six fold in the U.S. in the last three decades. Scientists suspect gastroesophageal reflux disease, or GERD, brought on by obesity may be to blame.

To learn more about esophageal adenocarcinoma, the research team interviewed more than 900 men and women in Los Angeles County who’d been diagnosed with the disease in either the esophagus or upper or lower regions of the stomach. They compared them to nearly 1,400 people without esophageal or stomach cancer.

Antacids may mask esophageal cancer.

They found that people who took nonprescription acid-neutralizing drugs regularly for more than three years were more than six times as likely to have esophageal adenocarcinoma than people who never took the drugs. And within this group, those who had no history of upper-gastrointestinal disorders were nearly 11 times as likely as non-drug-users to develop esophageal cancer.

Prescription acid-reducers weren’t associated with increased risk of esophageal cancer in this study, which was conducted before common drugs like cimetidine and omeprazole became available over the counter.

Some researchers have suggested that alkaline bile might play a role in increased risk. Stomach acid normally neutralizes bile, but regular, prolonged use of antacids could let the bile go unchecked and rise up the esophagus. This could lead to chronic tissue damage and raise cancer risk, Bernstein noted.

 However, it’s possible that some people who have precancerous conditions try to treat their discomfort with antacids rather than seeing a doctor, allowing cancer to develop unchecked.

“People may simply be self-medicating with antacids to reduce symptoms of undiagnosed disease,” she said. “Antacid use itself might not actually increase risk.”

Further study is needed to better understand how various acid-reducing medications influence risk. The study was published in the February issue of Cancer Epidemiology, Biomarkers & Prevention.