Long-term use of some acid reflux drugs linked to higher dementia risk

NEW YORK, Aug. 9 (UPI) -- Long-term use of acid reflux medications called proton pump inhibitors may increase the risk of dementia, according to a new study published Wednesday.

This research was published in the online issue of Neurology, the medical journal of the American Academy of Neurology.

While the study shows an association between acid reflux drugs and dementia, it does not prove that the drugs cause the general decline in function that impairs the ability to do everyday activities, the authors noted.

"Our study found that people who take acid reflux medications called proton pump inhibitors for 4 1/2 years or more may have a higher risk of dementia compared to people who do not take these medications. We did not find a higher risk of dementia with shorter-term use," the study's senior and corresponding author, Dr. Kamakshi Lakshminarayan, told UPI via email.

Lakshminarayan is a professor of epidemiology and community health at the University of Minnesota School of Public Health and a professor of neurology at the University of Minnesota Medical School in Minneapolis.

The major proton pump inhibitors sold in this country are omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid) and pantoprazole (Protonix).

Acid reflux occurs when stomach acid enters the esophagus, typically after eating a meal or when lying down. Heartburn and ulcers may ensue, and frequent acid reflux may progress to gastroesophageal reflux disease, or GERD, which can lead to esophageal cancer.

Proton pump inhibitors decrease stomach acid by targeting the enzymes in the stomach lining that produce that acid. They are commonly used to help manage acid reflux.

"Previous studies have shown that their use is linked to a higher risk of stroke, bone fractures and kidney disease," Lakshminarayan said. "We were interested to know if these drugs are linked to a higher risk of dementia, as well."

She said that "patients taking these medications should talk to their doctor before making any changes to discuss the best treatment for them. Stopping these drugs abruptly may result in worse symptoms."

The study's results are concerning because of the high prevalence of acid reflux and the widespread availability of over-the-counter drugs to combat it, said Dr. Marwan Sabbagh, a neurologist who specializes in Alzheimer's disease and cognitive disorders at Barrow Neurological Institute in Phoenix, who was not involved in the study.

"This is a worrisome development given how prevalent dementia is and how widespread the consumption of these medicines is," Sabbagh said via email.

But Dr. Thomas Wisniewski, professor of neurology, pathology and psychiatry at New York University Grossman School of Medicine, urged against jumping to firm conclusions.

"It's difficult to say that there's a causative link" between proton pump inhibitors and dementia, he told UPI in a telephone interview. "This is just an association. I think the take-home message for patients is that prolonged use of these medications (more than 4 1/2 years) should be avoided pending more information."

Proton pump inhibitor drugs, or PPIs, reduce acid in the stomach, which in turn lessens symptoms. However, Sabbagh speculated that they decrease absorption of vitamin B12-an important component of brain health.

"Also," he said, "PPIs will alter the gut microbiome, which might be providing immunological support to the brain."

Learning about the association between these drugs and dementia may cause fear and anxiety in some patients. "We might recommend restricting these meds, but that might mean the acid reflux symptoms return, which is associated with discomfort," Sabbagh said.

Researchers conducted their analyses using participants from the Atherosclerosis Risk in Communities Study, which launched in 1987. At the beginning of their investigation, they included 5,712 people, age 45 and older, who were dementia-free. The average age was 75.

During study visits and annual phone calls, the researchers reviewed patients' medications and determined if they took acid reflux drugs. A total of 1,490 people, or 26%, had taken the drugs.

Participants were followed for a median duration of 5 1/2 years. During this time, 585 of them, or 10%, developed dementia.

The researchers adjusted for factors such as age, sex and race, as well as health-related factors such as high blood pressure and diabetes.

They found that people who had been using acid reflux drugs for more than 4.4 years had a 33% higher risk of developing dementia than people who never took the drugs. Among those who took the drugs for fewer than 4.4 years, the researchers did not find a higher risk of dementia.

"Future studies should explore possible pathways or mediators between PPI use and the development of dementia," the researchers concluded in the report.

Treating acid reflux also may involve taking antacids, maintaining a healthy weight, and avoiding late meals and certain foods, Lakshminarayan said.

Different approaches may not benefit everyone, so it's important that people taking these medications consult their doctor before implementing any modifications. she said.

Wisniewski added that limiting or avoiding alcohol could help reduce the risk factors for GERD. "Ultimately, it's preferable to do some of these lifestyle things," he said.

The researchers acknowledged a limitation of their study: Participants were queried only once a year about medication use, so researchers estimated use between annual check-ins.

If participants stopped and resumed acid reflux drugs in between the check-ins, the estimation of their use may have been inaccurate. The authors also could not evaluate if participants took over-the-counter acid reflux drugs.

The National Institutes of Health, including the National Heart, Lung and Blood Institute, provided support for the study.