People who used common acid reflux medications for more than 4.4 cumulative years faced a 33% higher risk of developing dementia, according to a study published in Neurology by the American Academy of Neurology. The drugs in question, proton pump inhibitors, are among the most widely purchased over-the-counter medications in the United States, sold under brand names like Prilosec OTC, Nexium 24HR, and Prevacid 24HR. The finding has sharpened a long-simmering debate about whether these pills, designed for short-term relief, carry hidden long-term costs for the brain.
Long-term PPI use and a 33% jump in dementia risk
The research drew on data from the Atherosclerosis Risk in Communities Study, a decades-long federal project tracking cardiovascular and cognitive health across thousands of American adults. Investigators examined how cumulative exposure to proton pump inhibitors, commonly called PPIs, correlated with later dementia diagnoses. Among participants who had taken PPIs for more than 4.4 years, the hazard ratio for dementia was elevated by 33%, with a confidence interval reported alongside the central estimate. People who used the drugs for shorter stretches did not show the same statistical signal, which suggests that total duration of exposure, not simply whether someone ever took a PPI, is the variable that matters most.
PPIs work by blocking the enzyme system that pumps acid into the stomach. They were originally approved for short courses of treatment, typically two weeks at a time for over-the-counter versions. Yet millions of people take them continuously for months or years to manage chronic gastroesophageal reflux disease, or GERD. The FDA lists omeprazole, esomeprazole, and lansoprazole among the OTC proton pump inhibitors available without a prescription, making prolonged self-medication straightforward for anyone with persistent heartburn.
That accessibility is exactly what makes the new risk estimate so relevant. A drug class that requires no doctor visit and no refill authorization can easily accumulate years of total use without any clinician tracking the tally. The 4.4-year threshold identified in the study is not an exotic level of exposure; for someone who starts taking a daily PPI in their 50s and continues into their 60s, crossing that line is entirely plausible.
How the ARIC cohort shaped the dementia finding
The strength of the estimate rests heavily on the design of the underlying cohort. The Atherosclerosis Risk in Communities Study, known as ARIC, has followed participants since the late 1980s, collecting detailed medication histories and periodic cognitive assessments. Dementia surveillance at ARIC Visit 5 occurred in 2011 through 2013, when participants underwent structured neuropsychological testing and clinical adjudication to determine who met criteria for mild cognitive impairment or dementia. That rigorous diagnostic process sets the ARIC data apart from studies that rely solely on billing codes or prescription records to infer cognitive decline.
Because ARIC tracked medication use over many years rather than capturing a single snapshot, the researchers could calculate cumulative PPI exposure with unusual precision. This matters because earlier studies that looked only at current or recent PPI use produced inconsistent results, some finding elevated dementia risk and others finding none. By measuring total duration, the Neurology study isolated the dose-response pattern that shorter analyses missed: the risk signal appears only after years of accumulated use.
The study’s authors were careful to frame the result as an association, not proof that PPIs directly cause neurodegeneration. In public summaries of the work, the American Academy of Neurology emphasized that the link represents correlation rather than causation. That distinction is not a technicality. People who need PPIs for years often have other health conditions, take additional medications, and differ in diet and lifestyle from those who do not. Any or all of those factors could contribute to the observed gap in dementia rates.
What patients and doctors still do not know about PPIs and the brain
Several questions remain open. The study did not identify a biological mechanism that would explain how acid suppression in the stomach could accelerate cognitive decline. Researchers have proposed hypotheses in prior work, including the possibility that PPIs reduce absorption of vitamin B12 or alter gut microbiome composition in ways that affect brain health, but the ARIC analysis did not test those pathways directly. Without a confirmed mechanism, the statistical association sits in a gray zone: strong enough to warrant attention, but not strong enough to justify telling every long-term PPI user to stop immediately.
There is also no randomized controlled trial, the gold standard for establishing cause and effect, that has tested whether discontinuing PPIs reduces dementia incidence. Designing such a trial would be ethically and logistically difficult, because withholding effective acid suppression from people with severe reflux carries its own health risks, including esophageal damage and a small but real increase in esophageal cancer risk. Any trial would need to balance the potential cognitive benefits of reducing PPI exposure against the harms of uncontrolled acid reflux.
Another unknown is whether the dementia signal is specific to certain drugs within the PPI class, or whether it reflects a broader effect of long-term acid suppression. The Neurology study grouped PPIs together rather than comparing individual agents, so it cannot say whether, for example, omeprazole carries a different risk profile than esomeprazole. Nor can it determine whether other acid-reducing medications, such as H2 blockers, share similar associations or might represent safer alternatives for some patients.
How clinicians are likely to interpret the findings
For now, the practical message for doctors is one of caution rather than alarm. The data argue against casual, indefinite PPI use, especially in older adults, but they do not support abruptly stopping therapy in people who clearly need it. Clinicians are likely to pay closer attention to how long their patients have been on PPIs, revisit whether the original indication still applies, and consider step-down strategies such as lowering the dose, switching to on-demand use, or trying non-pharmacologic measures like weight loss and dietary changes.
Gastroenterologists have already urged periodic “deprescribing” reviews for long-term PPI users, in which the clinician and patient reassess whether benefits continue to outweigh risks. The dementia findings add another item to the risk column, alongside previously reported links between chronic PPI use and kidney disease, bone fractures, and certain infections. Each of those associations has its own uncertainties, but together they reinforce the idea that PPIs are not benign placebos and should be used at the lowest effective dose for the shortest feasible time.
Primary care physicians, who see many patients taking PPIs without specialist oversight, may also respond by more carefully documenting over-the-counter use. Because PPIs are inexpensive and widely advertised, patients often forget to mention them during medication reviews. Asking specifically about heartburn pills, and recording how long they have been used, could help identify people who have quietly crossed the multi-year exposure threshold highlighted in the study.
What patients can do now
For people currently taking PPIs, the new research is a signal to start a conversation, not to panic. No individual’s dementia risk can be predicted from this study alone, and stopping PPIs abruptly can cause rebound acid hypersecretion that makes symptoms worse. Patients who have been on these medications for years should talk with their clinicians about whether they still need daily therapy, whether a trial of tapering is appropriate, and what lifestyle changes-such as avoiding late-night meals, elevating the head of the bed, or reducing trigger foods-might allow for lower doses.
People who use PPIs only intermittently, or for brief courses as directed on the label, are unlikely to approach the cumulative exposure associated with higher dementia risk. For them, the main takeaway is to respect the time limits printed on over-the-counter packages and to seek medical evaluation if heartburn persists beyond a few weeks. Persistent symptoms may signal underlying conditions that require formal diagnosis and tailored treatment, not just indefinite self-medication.
Ultimately, the Neurology study adds an important piece to a complex puzzle. It suggests that the brain may pay a price when stomach acid is suppressed for years on end, but it stops short of proving that PPIs are to blame. As researchers continue to probe the connection, both patients and clinicians can respond by using these powerful drugs more thoughtfully-reserving long-term therapy for those who truly need it, and regularly reconsidering whether the balance of risks and benefits still comes out in favor of staying on the pill.
More from Morning Overview
*This article was researched with the help of AI, with human editors creating the final content.
