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Dr. Axe Wire · Study decoded · health
Acid Reflux Drug Use Linked to Higher Dementia Risk in Older Adults
A new meta-analysis links long-term acid-reflux drug use to higher dementia risk in older adults, though the size shifted with the comparison used.
A meta-analysis published October 28, 2026 in Clinical Pharmacology and Therapeutics found that older adults taking proton pump inhibitors, the common acid-reflux drugs known as PPIs, had an 18% higher rate of dementia than comparison groups, a link that grew or shrank depending on how the comparison was built. The study pooled 23 longitudinal studies of older adults who did not have dementia at start.
18%higher dementia risk
23studies pooled
75%higher vs non-H2RA users
Researchers pooled 23 longitudinal studies of older adults without dementia at baseline, comparing PPI users against various comparator groups. The combined result showed a hazard ratio of 1.18 (95% CI 1.02-1.37), an 18% higher dementia rate among PPI users overall. Against people taking H2 blockers, another acid-reducing drug class, the difference disappeared (hazard ratio 1.04, 95% CI 0.89-1.20). In an added analysis the authors had not planned, H2-blocker use alone was linked to a 44% higher rate (hazard ratio 1.44, 95% CI 1.07-1.93), and excluding H2-blocker users strengthened the PPI estimate to 75% higher (hazard ratio 1.75, 95% CI 1.38-2.22). Methods that handle timing bias, the risk of mistaking early dementia symptoms for a drug effect, gave 25% (hazard ratio 1.25) and 38% (hazard ratio 1.38) higher rates.
PPIs work by blocking the stomach's acid pumps. More broadly, long-term acid suppression can reduce absorption of nutrients like B12 and magnesium; this study did not test that mechanism. The authors conclude the link's strength and specificity depended substantially on comparator selection and time-bias handling, meaning part of what looks like a drug effect may reflect how the comparison was built.
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Dementia Risk Estimates Shifted With Comparison Method
This is a meta-analysis of observational studies, a link, not proof one causes the other. The comparator matters enormously: PPI users looked no different from H2-blocker users, yet H2-blocker use was itself linked to higher dementia risk. The authors call for long-term studies with active comparators to clarify whether PPIs themselves are responsible.
Dr. Axe’s Take
These drugs mute stomach acid for years but don't address why reflux started, whether that's food triggers, excess weight or a weak esophageal sphincter. The dementia link here is modest and moved with the comparison, so it isn't proof, but it rose to 75% higher once H2-blocker users were set aside. Separate from this study, long-term acid suppression is also known to lower absorption of B12 and magnesium, a side effect worth checking with bloodwork. I'd want reflux addressed at the root, not just refilled. Any change to a prescription is one to make with your doctor.
— Dr. AxeStudy summary
- Who
- 23 longitudinal studies of older adults without dementia at baseline, PPI users vs. comparator groups.
- Design
- Meta-analysis of observational studies; MEDLINE, Embase, CENTRAL searched through January 25, 2026.
- Dose
- Not reported (pooled PPI use vs. comparator exposure across studies).
- Primary result
- Pooled HR 1.18 (95% CI 1.02-1.37): 18% higher dementia rate in PPI users overall.
- Secondary
- No difference vs. H2RA users (HR 1.04, CI 0.89-1.20); H2RA use alone linked to 44% higher risk (HR 1.44); excluding H2RA users raised PPI estimate to 75% higher (HR 1.75, CI 1.38-2.22); lag-time method HR 1.25, time-varying method HR 1.38.
- Funding / conflicts
- Competing interests: The authors declared no competing interests for this work. Funding not reported in the abstract.
- Date
- Oct 28, 2026