Drug taken for common condition linked to 33% higher risk of dementia

Long term use of a type of acid reflux drug increases the risk of dementia by a third, warns new research. Scientists found that people who take proton pump inhibitors, or PPIs, for four and a half years or more were 33 per cent more likely to develop the debilitating condition.

Acid reflux is when stomach acid flows into the oesophagus, usually after eating or when lying down. People with acid reflux may experience heartburn and ulcers, while those who suffer frequent bouts of acid reflux may develop gastroesophageal reflux disease, or GORD, which can lead to cancer of the oesophagus.

GORD is a very common condition, with up to 40 per cent of the UK population experiencing regular heartburn. PPIs reduce stomach acid by targeting the enzymes in the stomach lining that produce it.

But the medication has been previously linked to higher risk of stroke, broken bones and kidney disease. The American research team, whose findings were published in the journal Neurology, say the study does not prove that acid reflux drugs cause dementia; it only shows an association.

Study author Professor Kamakshi Lakshminarayan 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.” The study included more than 5,700 people, age 45 and older, who did not have dementia at the start of the study. The participants had an average age of 75. The research team determined if the participants took acid reflux drugs by reviewing their medications during study visits and during yearly phone calls.

Of the participants, 1,490 (26 per cent) had taken the drugs. They were then divided into four groups based on whether they had taken the drugs and for how long: people who didn’t take the drugs; those who took the drugs for up to 2.8 years; those who took them for 2.8 to 4.4 years; and people who took them for more than 4.4 years.

The participants were then followed for an average of around 5.5 years. During that time, 585 (10 per cent) developed dementia. Of the 4,222 people who did not take the drugs, 415 people developed dementia, or 19 cases per 1,000 person-years.

Person-years represent both the number of people in the study and the amount of time each person spends in the study. Of the 497 people who took the drugs for more than 4.4 years, 58 people developed dementia, or 24 cases per 1,000 person years.

After adjusting for factors such as age, sex and race, as well as health-related issues such as high blood pressure and diabetes, the researchers calculated that people who had been taking acid reflux drugs for more than 4.4 years had a 33 per cent higher risk of developing dementia than people who never took the drugs.

Researchers did not find a higher risk of dementia for people who took the drugs for fewer than 4.4 years. Prof Lakshminarayan, of the University of Minnesota School of Public Health, said: “More research is needed to confirm our findings and explore reasons for the possible link between long-term proton pump inhibitor use and a higher risk of dementia.

“While there are various ways to treat acid reflux, such as taking antacids, maintaining a healthy weight, and avoiding late meals and certain foods, different approaches may not work for everyone.”

She added: “It is important that people taking these medications speak with their doctor before making any changes, to discuss the best treatment for them, and because stopping these drugs abruptly may result in worse symptoms.”