Experts say drug commonly taken by millions can increase dementia risk 33 per cent

Doctors have warned about the risks of long-term use of the drug, which has also been linked to strokes, bone fractures and chronic kidney disease.

New research has warned that the long term use of one commonly taken drug could increase the risk of developing dementia by one third.

Studying the impact of proton pump inhibitors, or PPIs, scientists found that people who take these drugs for four-and-a-half years, or more, were 33 per cent more likely to develop the debilitating condition.

PPIs work to reduce the production of acid in the stomach and are commonly used to ease symptoms of indigestion, including acid reflux. Acid reflux is caused when stomach acid flows into the oesophagus and commonly occurs after eating or when lying down.

People who have acid reflux may also suffer from heartburn, which up to 40 per cent of the UK population report regularly experiencing. Others who suffer particularly frequent bouts of acid reflux may develop gastroesophageal reflux disease, or GORD, which can lead to cancer of the oesophagus.

While PPIs ease acid reflux, the medication has also been linked to increased risk of developing broken bones, strokes and kidney failure. Scientists have now also conducted research to uncover the impact of the drugs on developing dementia, Surrey Live reports.

Findings from the American research team’s study have been published in the journal, Neurology. The research team said their findings do not prove that acid reflux causes dementia, and instead only shows an association.

Study author and practicing vascular neurologist, 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.”

More than 5,700 people took part in the study, with participants all aged 45 or over, and having an average age of 75 in total. All participants were deemed as not having dementia at the start of the study.

During the study, 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.

The team then divided participants 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.

Over the next five-and-a-half years, participants were followed to study whether taking PPIs showed an association with developing dementia.

During the time of the study 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. 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.

Person-years represent both the number of people in the study and the amount of time each person spends in the study.

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

The study did not show an increased risk of dementia for people who took PPIs 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.”