BACKGROUND

This study aimed to investigate associations between historic phone use, visual decline, and risk of dementia, as well as underlying biological mechanisms.

METHODS

494,359 participants from UK Biobank were included in the prospective study. Historic phone use, visual acuity, brain imaging, and leukocyte telomere lengths (LTLs) were assessed. Incident dementia was tracked via hospital episode records and mortality data.

RESULTS

Over a median follow-up of 12.2 years, participants with better visual acuity were associated with longer use of mobile phone. Longer historic phone use was associated with a 31% lower risk of dementia. Both hippocampal gray matter volumes and LTLs were associated with historic phone use length and significantly mediated the relationship between historic phone use and dementia. Mediation still exists in participants with visual decline.

CONCLUSION

Our findings suggest mobile phone use may serve as a modifiable factor to prevent dementia, even in older adults with visual decline.

HIGHLIGHTS

A strong inverse association was observed between longer mobile phone use and lower dementia incidence, potentially mediated by changes in hippocampal gray matter volume and LTL.Mobile phone use may benefit individuals with age-related visual decline by reducing dementia risk, given the well-established link between vision impairment and increased dementia risk.Middle-aged and older adults should be encouraged to use mobile phones as a means to enhance social connectivity.