A common class of acid reflux medication, taken by millions, has been associated with a 33% increased risk of dementia when used long-term, according to new research. Scientists discovered that individuals who take proton pump inhibitors (PPIs) for four and a half years or more are significantly more likely to develop the debilitating condition.
Understanding Acid Reflux and PPIs
Acid reflux occurs when stomach acid flows back into the oesophagus, often after eating or when lying down. Symptoms include heartburn and ulcers, and frequent episodes can lead to gastroesophageal reflux disease (GORD), which may increase the risk of oesophageal cancer. GORD is highly prevalent, affecting up to 40% of the UK population with regular heartburn. PPIs work by reducing stomach acid production through targeting enzymes in the stomach lining.
Previous Health Concerns
The medication has previously been linked to a higher risk of stroke, bone fractures, and kidney disease. The American research team, whose findings appear in the journal Neurology, emphasises that the study does not prove causation but rather an association.
Study author Professor Kamakshi Lakshminarayan, a vascular neurologist at the University of Minnesota School of Public Health, stated: “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.”
Study Details
The study included more than 5,700 participants aged 45 and older, none of whom had dementia at the outset. The average age was 75. Researchers tracked medication use through study visits and annual phone calls. Of the participants, 1,490 (26%) had taken PPIs. They were categorised into four groups: non-users, those using PPIs for up to 2.8 years, those using for 2.8 to 4.4 years, and those using for more than 4.4 years.
Participants were followed for an average of 5.5 years. During this period, 585 (10%) developed dementia. Among the 4,222 non-users, 415 developed dementia (19 cases per 1,000 person-years). Person-years account for both the number of participants and the duration of their involvement. Of the 497 long-term users (over 4.4 years), 58 developed dementia (24 cases per 1,000 person-years).
Adjusted Risk Calculation
After adjusting for age, sex, race, and health issues like high blood pressure and diabetes, the researchers calculated that those taking PPIs for more than 4.4 years had a 33% higher risk of developing dementia compared to non-users. No increased risk was observed for shorter-term use.
Expert Commentary
Professor Lakshminarayan added: “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 stressed: “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.”
