Can This Vaccine Help Prevent Alzheimer's?

Can a shingles vaccine cut your dementia risk by 20%?

A series of landmark studies — published in Nature, Cell, and JAMA — say yes.

In this episode, Tommy unpacks the research: how natural experiments in four countries produced one of the most compelling signals in dementia prevention, what might explain the effect beyond infection prevention, and what it means for your own vaccination decisions.

In this episode:
00:00 — Introduction
00:52 — The new data on shingles vaccination and Alzheimer's risk
01:48 — The Stanford group and their regression discontinuity methodology
03:15 — How birthday-based eligibility creates a natural experiment (Wales, Canada, Australia)
05:28 — Results: a ~20% reduction in dementia diagnoses across all countries
06:52 — The Cell paper follow-up: benefits at every disease stage (unimpaired → MCI → dementia)
07:55 — Shingrix vs. Zostavax: the US natural experiment and a potentially larger effect
09:08 — Why does it work? Preventing illness, avoiding bed rest and disuse, immunomodulation
11:29 — Neuroinflammation and possible immune system "tuning" effects
12:27 — The sex difference: greater benefit in women in most (but not all) studies
15:52 — Summary of the evidence and what it means for dementia prevention strategy
17:36 — Josh's take: number needed to treat analysis
19:15 — Heterogeneous pathways to dementia and why vaccination fits the toolkit
21:13 — Practical advice: when to get vaccinated, repeat dosing, and personal risk assessment
25:36 — Wrap-up and how to submit questions

Links & Resources:

• Shingles vaccine and dementia studies: Nature (Wales, 2025), Cell (Wales follow-up), JAMA/Lancet (Canada, Australia, US)
• Flu vaccine and dementia: Neurology (2026)
• Tommy's book: The Stimulated Mind

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Intro and Outro music composed and produced by Julienne Ellen.