Popular heartburn medicine may increase dementia risk by 33%. What to know to stay safe.

People who use a common type of acid reflux drug for more than four years face a higher risk of dementia later in life, a new study found.

The research examined people prescribed proton pump inhibitors for frequent acid reflux, stomach ulcers, or other digestive tract issues. Those who took the drugs for more than 4.4 years had a 33% greater likelihood of developing dementia compared to those who did not take the medication, according to a study published Wednesday in the medical journal "Neurology."

Acid reflux occurs when acid escapes the stomach and reaches the esophagus, often after a meal or when going to bed. The common condition can cause gastroesophageal reflux disease, which can damage the esophagus and increase cancer risk. Proton pump inhibitors reduce stomach acid by targeting acid-producing enzymes in the stomach lining.

The study is the latest to link these medications used by millions of Americans to a growing list of conditions such as stroke, heart disease and kidney disease.

Previous studies have reported mixed results on links to dementia. Two robust reviews − both examining a collection of independent studies − found no significant links between dementia or Alzheimer's disease and the use of proton-pump inhibitors.

And while authors of the National Institutes of Health-funded "Neurology" study caution it does not prove these medications cause dementia, they said it provides evidence that sustained use of these medications could pose a risk for dementia, which afflicts about 1 in 3 adults ages 85 and older.

"Patients should talk to their doctors and share with them all the medications they are taking," said Kamakshi Lakshminarayan, the study's author and a vascular neurologist and researcher at the University of Minnesota School of Public Health. "They can review the medications, including any over-the-counter medications they may be taking, and discuss the reasons for taking each medication with their doctor"

What are the risks for longer-term use?

The study included more than 5,700 people who did not have dementia at the start of the study. Researchers followed the study participants for 5.5 years. Participants had an average age of 75.

Researchers reviewed study participants during in-person visits or once-a-year phone calls. Those who were prescribed the acid-reflux medications were placed in four groups based on how long they took the medications. Those who took the drugs for at least 4.4 years had the highest rates of dementia. The study excluded people who used over-the-counter versions of the drugs, which have been sold without a prescription since 2003. Some over-the-counter versions are sold under the brand names Prilosec, Nexium and Prevacid.

Researchers adjusted the results for age, sex, race and chronic conditions, such as high blood pressure and diabetes. Participants who used the medication for at least 4.4 years had a 33% higher risk of developing dementia compared to those who never took the drugs, the study said. Those who used the drug for a shorter period did not have a higher risk of dementia.

Lakshminarayan said the study provides valuable clues because it evaluated dementia risk for those who took the drug for a while. Dementia was determined by cognitive screening reviewed by doctors. Some past studies have provided a one-time look at medication use and relied on billing data for a dementia diagnosis.

How do I safely take acid reflux drugs?

Dr. Fouad J. Moawad, a gastroenterologist and spokesman for the American Gastroenterological Association, said past studies with conflicting results on dementia risk can be "confusing for both patients and prescribers."

He said the design of the new study does not measure factors that might influence results, including vitamin B12 deficiency, depression, socioeconomic status and H. pylori, a type of bacteria that can infect the stomach. He added that it's difficult to tell whether patients take the acid-reflux drugs as needed, for brief periods or long term. Also, the study excluded people who took over-the-counter versions of the drugs.

In 2022, the American Gastroenterological Association updated its guideline for doctors on when acid-reflux drug prescriptions should be reduced or discontinued.

Moawad recommends taking the lowest effective dose for those who need the drugs to control stomach acid for severe reflux esophagitis, Barrett’s esophagus and peptic ulcers. He also recommends people reduce foods known to trigger stomach acid, don't eat within three hours of sleeping, elevate their head when sleeping and lose weight.

Proton pump inhibitors are "well-tolerated drugs and work well for acid-related disorders, " Moawad said. "With that said, PPIs are likely overprescribed. I often advise my patients to weigh the risks and benefits of any medical treatment."

Ken Alltucker is on Twitter at @kalltucker, or can be emailed at alltuck@usatoday.com.

This article originally appeared on USA TODAY: Heartburn relief medicine for acid reflux raises dementia risk: study