A No-Brainer for Protecting Your Brain (Economist)

Section: Leaders · Edition: 2026-07-11 Edition · Print headline: "A no-brainer for your brain"

Summary

A Leader arguing that dementia is less inevitable than the headline forecasts suggest, that a long list of lifestyle and medical risk factors is already bending the age-adjusted curve downward in rich countries, and that one intervention stands out for its effort-to-benefit ratio: a course of the shingles vaccine, associated with about a 20% lower risk of dementia. The policy ask is that health systems stop rationing the vaccine by age. The piece is an editorial; its claims rest on studies it describes but does not name (see below).

Key claims

• Forecasts vs trend. Models predict dementia cases may triple to 153m by 2050 as societies age. But in rich countries the age-adjusted risk of getting dementia "has dropped sharply in recent decades"; most models assume the decline stops or reverses, and the Leader argues "a mountain of new evidence shows that need not be".
• Risk factors people are already acting on. Lifestyle: healthy diet, more exercise, keeping the brain active, drinking less. Medical: treating hearing loss, depression, high blood pressure and high cholesterol. The Leader's caveat: adoption and adherence are hard, and the pay-off needs "many years" of healthy habits before the brain benefits.
• The shingles-vaccine finding. A course of the shingles vaccine "may reduce the risk of dementia by about 20%". Two candidate mechanisms are offered: the dormant varicella-zoster virus damages or inflames the nervous system, so suppressing it helps; or vaccination broadly activates the immune system against other pathogens implicated in dementia. The Leader says the mechanism "is still being debated".
• Old vs new vaccine. Most of the anti-dementia evidence relates to the older live attenuated vaccine (Zostavax), largely replaced by Shingrix, a recombinant protein vaccine that cannot cause infection. "Some studies suggest" Shingrix may be at least as powerful against dementia. The Leader calls for randomised trials to settle which is better, the optimal age, and whether boosters are needed.
• Rationing. Shingles itself afflicts 20–30% of unvaccinated people, and several studies find vaccination cost-effective from about age 55 on shingles alone. Yet Britain only lowered eligibility from 70 to 65 in 2023 and has been slow to reach the late-60s cohort; only 17 of 27 EU members recommend the vaccine at all, several only for over-65s.
• Cost. A full two-dose Shingrix course costs the NHS £320 ($430) and US federal immunisation programmes about $270; UK retail is about £460.

The studies behind the Leader (vault identification, not named in the text)

• The ~20% / "course of the shingles vaccine" figure matches the Welsh natural experiment (Eyting et al., Nature, 2025): people born just after the 2 September 1933 eligibility cutoff for Zostavax were compared with those born just before; over about seven years the vaccinated group had a roughly 20% relative (≈3.5 percentage-point absolute) reduction in new dementia diagnoses, with a larger effect in women. A regression-discontinuity design, not a randomised trial.
• The "Shingrix may be at least as powerful" line matches Taquet et al. (Nature Medicine, 2024), a US electronic-health-record comparison of Shingrix vs Zostavax recipients showing a lower dementia-diagnosis rate over six years for the recombinant vaccine.
• The risk-factor list (hearing loss, depression, hypertension, high LDL cholesterol, exercise, diet, cognitive activity, alcohol) is the 2024 Lancet Commission on dementia list: 14 modifiable risk factors that the Commission estimates account for about 45% of dementia cases worldwide. See Dementia Prevention.
• The 153m by 2050 forecast is the Global Burden of Disease projection (Lancet Public Health, 2022).

What is flagged as unproven

• Causation and mechanism. The 20% figure comes from observational and quasi-experimental designs; the Leader itself asks for randomised trials.
• Which vaccine, what age, whether boosters are needed: explicitly open.
• Whether the age-adjusted decline continues: the Leader asserts it need not stop, against the modellers' assumption; this is an argument, not a measurement.

Connects to

• Dementia Prevention — concept page: risk-factor evidence plus the vaccine finding
• The Brain May Be About to Have Its Ozempic Moment (Economist) — the other brain-health pick of this batch
• Eli Lilly — testing donanemab in pre-symptomatic patients is the pharmaceutical version of the same prevention bet
• GLP-1s — prevention-medicine framing shared across the vault's health thread