An Unexpected Ally In Dementia Prevention: Shingles Vaccination
The strongest causal evidence yet from a ‘natural experiment’ study.
I did a joint BSc(Hons) degree in biology-psychology and then an MSc in life sciences (major in neuroscience). I believe I went through over 50 textbooks throughout my student years. (Yes, I was a study freak.) But nowhere in the textbooks did I ever come across the theory that infections could ‘seed’ or promote the development of dementia.
Dementia refers to disorders involving memory loss, of which the most common type is Alzheimer’s disease (AD). Established textbook knowledge informs us that AD is caused by a build-up of amyloid plaques in the brain. But what causes this build-up exactly remains unknown.
Convincing research in the last two decades has pinpointed infections, notably herpesviruses, as the likely cause, which I’ve written about before in Medium here. If infections are a risk factor for dementia, then vaccines targeting those infections should be a protective factor.
Association between vaccination and dementia
Indeed, numerous studies have found an association between vaccination and reduced dementia risk. Here are a few notable ones:
