It can be hard to prove exactly what causes dementia ― researchers think exercise, socialising, and eating well can all have preventative effects, but it’s hard to place boundaries on where causation ends and other factors, like class and environment, begin.
A 2023 paper published in the Journal of the American Geriatrics Society, however, brought another variable in: internet use.
The study, which looked at 18,154 dementia-free adults aged 50-65 over 17 years, relied on data from the University of Michigan’s Health and Retirement Study.
From 2002-18, participants were asked about their internet use every two years.
Researchers then compared their responses to dementia development data.
How did internet use affect dementia rates?
“Regular internet users experienced approximately half the risk of dementia than non-regular users,” the researchers found.
But those who spent a lot of time on the internet (6-8 hours) were also at an increased risk.
The scientists explained: “Being a regular internet user for longer periods in late adulthood was associated with delayed cognitive impairment, although further evidence is needed on potential adverse effects of excessive usage.”
65% of participants considered themselves regular internet users.
“The lowest risk was observed among adults with 0.1–2 hours of [internet] usage,” the paper reads, “though estimates were non-significant due to small sample sizes.”
“The difference in risk between regular and non-regular users did not vary by educational attainment, race-ethnicity, sex, and generation,” they add.
Does this prove internet use, or lack thereof, definitely causes or prevents dementia?
Absolutely not. The study only sought to find an association, and the researchers themselves say more research is needed to see how this data bears out.
Speaking to Medscape, Claire Sexton of the Alzheimer’s Association, who is not associated with this study, said: “It may be that regular internet usage is associated with increased cognitive stimulation, and in turn reduced risk of dementia; or it may be that individuals with lower risk of dementia are more likely to engage in regular internet usage.”
She agrees with the paper’s researchers in saying, “interventional studies are able to shed more light on causation.”