Common reflux drugs may raise dementia risk if taken for several years, new research suggests.
Scientists found that long-term use of proton pump inhibitors, or PPIs, was linked to a 33 per cent increased risk of dementia.
However, experts said the study does not prove the drugs directly cause the condition, only that a link was observed.
Study author professor Kamakshi Lakshminarayan, a vascular neurologist, said the findings add to growing concerns around prolonged use of the drugs.
She said: “Proton pump inhibitors are a useful tool to help control acid reflux, however long-term use has been linked in previous studies to a higher risk of stroke, bone fractures and chronic kidney disease.”
“Still, some people take these drugs regularly, so we examined if they are linked to a higher risk of dementia.”
“While we did not find a link with short-term use, we did find a higher risk of dementia associated with long-term use of these drugs.”
PPIs are widely prescribed medicines used to treat gastro-oesophageal reflux disease, or GORD, stomach ulcers and persistent indigestion.
They work by reducing the amount of acid produced in the stomach.
Popular PPIs include omeprazole, lansoprazole and pantoprazole.
The US study tracked more than 5,700 adults aged 45 and older who did not have dementia at the beginning of the research.
Participants had an average age of 75 and were monitored for roughly five and a half years.
Researchers recorded medication use during study appointments and through annual telephone interviews to assess if participants were taking acid reflux drugs.
During the follow-up period, 585 people, around 10 per cent of the group, developed dementia.
Among the 4,222 people who did not take PPIs, 415 developed dementia, equivalent to 19 cases per 1,000 person-years.
Person-years is a measure used in research to reflect both how many people are in a study and how long they are followed.
After accounting for factors including age, sex, race, high blood pressure and diabetes, researchers found that people who had used PPIs for more than 4.4 years had a 33 per cent greater likelihood of developing dementia compared with those who had never taken the medicines.