Called proton pump inhibitors (PPIs), this group of drugs includes omeprazole (Losec, generics and Olex), esomeprazole (Nexium) and lansoprazole (Prevacid.) They work by lowering the amount of acid produced by the stomach.
But German researchers found that people 75 or older who regularly take the medications had a 44 per cent increased risk of dementia, compared with seniors not using the drugs. The study only found an association, however, and not a cause-and-effect link.
"To evaluate cause-and-effect relationships between long-term PPI use and possible effects on cognition in the elderly, randomized, prospective clinical trials are needed," said corresponding author Britta Haenisch, from the German Center for Neurodegenerative Diseases in Bonn.
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The report was published Feb. 15 in the journal JAMA Neurology.
Boustani said earlier studies have linked another type of antacid, H2 blockers, with an increased risk of dementia. Up to now, he's recommended that patients use PPIs to treat acid reflux and steer clear of H2 blockers like cimetidine (Tagamet), famotidine (Pepcid) and ranitidine (Zantac).
More than 15 million Americans used prescription PPIs in 2013, at a total cost of more than $10 billion US, according to a report by the IMS Institute for Healthcare Informatics.
As many as 70 per cent of PPI prescriptions in the United States have been inappropriately handed out by doctors, and 25 per cent of long-term users could stop taking the medication without suffering increased heartburn or acid reflux, according to a study published in January in the journal JAMA Internal Medicine.
And now the German researchers report there also is some evidence that PPI use might affect a person's ability to reason.
To test the possible association between PPIs and dementia, the German researchers collected data from a large German health insurance firm on almost 74,000 seniors aged 75 or older. The data ran from 2004 to 2011, and included diagnoses and drug prescriptions.
Regular users of PPIs had a 44 per cent increased risk of dementia compared with those not receiving PPI medications.
If over-the-counter PPIs are available, then more people might have been taking them and the dementia risk described in this paper could be overestimated, Swaminath said.
People who want to ease off PPIs can take a number of steps to reduce excess acid or prevent acid reflux, Boustani said. They can eat smaller meals, lay off chocolate and caffeine, and stay upright for a few hours following each meal.
Dr. Gisele Wolf-Klein, director of geriatric education at North Shore-LIJ Health System in New Hyde Park, N.Y., added that even the researchers aren't sure why PPIs would affect the aging brain.
Another expert agreed.
"It does not tell us anything that should change medical practice right now," Fargo said. "I don't think there's going to be an uprising among doctors telling patients not to take their PPIs. This doesn't rise anywhere near the level of evidence you would need for that."
"Both of those things, we know, are risk factors for developing cognitive decline and dementia in later life, and both of those are reasons why a person might need to take a proton pump inhibitor," Fargo explained.