September 20, 2026
A promising link, but only one part of protecting brain health
By GA Richards, Emeritus Professor of Critical Care and Pulmonology, University of the Witwatersrand | MBBCh, PhD, FCP(SA),MASSAf
As populations age, dementia is becoming increasingly common. A 2025 US estimate suggested that the lifetime risk of developing dementia after age 55 may be as high as 42%, with risk varying according to factors such as sex, ethnicity and genetics. APOE e4 is an important genetic risk factor for Alzheimer's disease, but it does not determine with certainty whether someone will develop the condition.
Dementia is an umbrella term that includes Alzheimer's disease, vascular dementia, Lewy body dementia and other conditions. Alzheimer's disease is the most common cause. Newer anti-amyloid treatments may modestly slow progression in carefully selected people with early Alzheimer's disease, but they do not reverse the disease or restore lost cognition. They are costly, require specialist assessment and monitoring, and may cause serious side effects.
Although there is no single way to prevent dementia, growing evidence supports addressing modifiable risk factors—particularly from midlife. Protecting the heart and blood vessels also helps protect the brain. Important measures include:
· Blood pressure: Detect and manage hypertension. Current guidance generally supports a systolic target below 130 mmHg for adults with hypertension, where clinically appropriate.
· Cholesterol and vascular risk: Review your full lipid profile and overall cardiovascular risk with your doctor. Statins may be recommended to reduce cardiovascular and stroke risk; treatment targets should be personalised.
· Diabetes and smoking: Good glucose control and avoiding tobacco are important for both vascular and brain health.
· Lifestyle: Regular physical activity, a balanced diet, healthy sleep, social connection, hearing care and ongoing cognitive stimulation all form part of a comprehensive risk-reduction plan.
In the Finnish FINGER study, a two-year programme combining diet, exercise, cognitive training and vascular-risk monitoring produced greater improvement in overall cognitive performance than general health advice alone. Similar multi domain approaches are now being studied internationally.
After chickenpox, the varicella-zoster virus remains dormant in the nervous system and may later reactivate as shingles. Researchers are investigating whether preventing reactivation, or the immune response produced by vaccination, could also influence long-term brain health.
A 2025 natural experiment in Wales examined the older live-attenuated shingles vaccine, Zostavax. Over seven years, eligibility for vaccination was associated with an approximately 20% relative reduction in new dementia diagnoses. This important study did not investigate Shingrix.
A separate 2024 observational study compared the newer recombinant vaccine, Shingrix, with Zostavax. Shingrix was associated with 17% more time lived without a dementia diagnosis over the following six years—equivalent to 164 additional diagnosis-free days among people who later developed dementia. Because this was an observational study, it demonstrates an association rather than proving that Shingrix prevents dementia.
Emerging research has also reported an association between recombinant shingles vaccination and a lower risk of cardiovascular events. These findings are encouraging, but the vaccine is currently recommended primarily to prevent shingles and its complications—not as an established treatment to prevent dementia or heart disease.
Shingrix is a non-live recombinant shingles vaccine. International guidance recommends two doses for adults aged 50 years and older, as well as certain younger adults who are or will be immunocompromised. For most adults, the second dose is given two to six months after the first. A shorter one- to two-month interval may be considered in some immunocompromised patients.
People who previously received Zostavax can still receive Shingrix. Guidance recommends waiting at least eight weeks after Zostavax, while the most appropriate timing should be discussed with your doctor according to your age, health and individual risk. No routine booster is currently recommended after completion of the two-dose Shingrix series.
The possible relationship between shingles vaccination and reduced dementia risk is exciting, but no vaccine should be viewed in isolation. The most meaningful approach remains proactive and personalised: understand your risk factors, manage vascular health, maintain healthy daily habits and keep recommended vaccinations up to date.
If you would like to discuss whether Shingrix is appropriate for you, or review your personal cardiovascular and dementia risk factors, please contact the Infinity Medical Concierge team.
Rubin R. Nearly Half of Dementia Cases May Be Preventable—Here's What the Research Says So Far.JAMA. Published online September 4, 2026.
Eyting M, XieM, Michalik F, et al. A natural experiment on the effect of herpes zoster vaccination on dementia. Nature. 2025;641:438-446.
Taquet M, etal. The recombinant shingles vaccine is associated with lower risk of dementia. Nature Medicine. 2024.
Corsi-Zuelli F,Li F, Upthegrove R, et al. Recombinant shingles vaccination and the risk of cardiovascular events. Nature Medicine. 2026.
This article is intended for general education and does not replace personalised medical advice. Vaccination and treatment decisions should be made with your healthcare professional.
