Vaccination, Diabetes Medications, and Dementia Risk: Latest Research

Recent studies are shedding light on the complex relationship between common medical interventions – vaccination and diabetes medication – and the risk of developing dementia. While concerns have been raised regarding potential links between vaccines and cognitive decline, emerging evidence suggests a more nuanced picture, with certain vaccines potentially offering protective benefits. Simultaneously, research indicates specific diabetes medications may play a role in reducing dementia risk. This article explores the latest findings, providing an evidence-based overview of these critical areas.

Vaccination and Dementia Risk: A Closer Look

The impact of vaccination on dementia risk has been a subject of ongoing investigation. Several recent systematic reviews and meta-analyses have provided valuable insights.

Influenza Vaccination

A systematic review published in Age and Ageing in 2025 analyzed eight cohort studies encompassing nearly 10 million participants. The findings suggest that influenza vaccination is associated with a reduced risk of incident dementia in high-risk populations, such as individuals with chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), and vascular disease (HR 0.93; 95% CI: 0.86-1.01). Notably, multiple doses of the influenza vaccine demonstrated a stronger association with reduced dementia risk (2-3 doses: HR 0.84; 95% CI: 0.76-0.92; ≥ 4 doses: HR 0.43; 95% CI: 0.38-0.48). Yang W-K et al. (2025)

Other Adult Vaccinations

Another systematic review, too published in 2025, examined the association between various adult vaccinations and dementia risk. This analysis of 21 studies (over 104 million participants) revealed that vaccination against herpes zoster was associated with a reduced risk of any dementia (RR 0.76) and Alzheimer’s disease (RR 0.53). Influenza vaccination was also linked to a reduction in dementia risk (RR 0.87), as was pneumococcal vaccination for Alzheimer’s disease (RR 0.64). Tetanus, diphtheria, and pertussis (Tdap) vaccination showed a significant reduction in any dementia (RR 0.67). Maggi S et al. (2025)

These findings collectively suggest that adult vaccinations, particularly against herpes zoster, influenza, pneumococcus, and Tdap, may be associated with a lower risk of dementia and support the incorporation of vaccination strategies into public health initiatives for dementia prevention.

Diabetes Medications and Dementia Risk

Given the established link between diabetes and an increased risk of dementia, researchers have been investigating whether specific diabetes medications can mitigate this risk.

GLP-1 Receptor Agonists (GLP-1 RAs)

Multiple studies highlight the potential benefits of glucagon-like peptide-1 receptor agonists (GLP-1 RAs). A systematic review and meta-analysis published in the Journal of Alzheimer’s Disease in 2025 found that GLP-1 RAs reduced dementia risk by 53% in randomized controlled trials (RR=0.47) and 27% in case-control studies (RR=0.73). Hui EK et al. (2025). A separate meta-analysis of randomized clinical trials, published in JAMA Neurology in 2025, confirmed these findings, demonstrating a statistically significant reduction in all-cause dementia with GLP-1RA employ (OR, 0.55 [95%CI, 0.35-0.86]). Seminer A et al. (2025)

Other Diabetes Medications

Research also suggests potential benefits from glitazones, which consistently showed protective effects against dementia. However, findings regarding metformin, sulfonylureas, dipeptidyl peptidase-IV inhibitors (DPP-1V), and insulin have been inconsistent.

Systemic Medications and Cognitive Impairment: An Umbrella Review

An umbrella review of meta-analyses published in Molecular Psychiatry in 2025 examined the broader impact of systemic medications on dementia risk. The review found moderate certainty evidence of reduced dementia risk associated with anti-hypertensives, statins, sodium-glucose transport protein 2 (SGLT2) inhibitors, and GLP-1 RAs. Conversely, there was moderate certainty of increased risk associated with anticholinergic drugs. Belessiotis-Richards C et al. (2025)

The authors recommend proactive treatment of hypertension to reduce dementia risk and advise avoidance of anticholinergic drugs in individuals with cognitive impairment.

Key Takeaways

• Influenza and other adult vaccinations may offer protection against dementia, particularly in high-risk populations.
• GLP-1 RAs, a class of diabetes medications, show promising results in reducing dementia risk.
• Managing hypertension and avoiding anticholinergic medications are vital considerations for cognitive health.

Further research is ongoing to fully elucidate the complex interplay between medical interventions and dementia risk. These findings underscore the importance of proactive healthcare strategies, including vaccination and appropriate management of chronic conditions like diabetes, in promoting long-term cognitive health.