The role of beverage consumption in dementia prevention, particularly regarding substitution effects and interactions with modifiable risk factors, remains unclear. This study aimed to evaluate the associations of major beverage types and their substitution effects with the risk of all-cause dementia.

A prospective cohort study.

We included 118,963 dementia-free participants (2006–2010 baseline) with complete dietary questionnaires from the UK Biobank.

Self-reported intake of sugar-sweetened beverages, artificially sweetened beverages, natural juices, coffee, and tea was assessed through 24-h dietary recall. The primary outcome was incident all-cause dementia, ascertained through linked primary care, hospital admission, and mortality registration data. Associations between beverage intake and dementia risk were evaluated using Cox proportional hazards models, yielding hazard ratios (HRs) and 95% confidence intervals (CIs). Substitution modeling assessed the effects of replacing one beverage with another. Interaction analyses explored variations by modifiable risk factors, including obesity, hypertension, depression, or dyslipidemia.

Over 13.45 years, 992 all-cause dementia cases were recorded. Higher sugar-sweetened beverage intake (> 1 glass/day) was associated with an increased risk of all-cause dementia (HR, 1.61; 95% CI, 1.28–2.02; P < 0.001). Coffee and tea consumption were associated with a lower risk of all-cause dementia. Substituting sugar-sweetened beverages or artificially sweetened beverages with coffee or tea significantly reduced the risk of all-cause dementia. These protective associations were strongest among individuals with obesity, hypertension, depression, or dyslipidemia.

Replacing sugar-sweetened beverages or artificially sweetened beverages with coffee or tea was associated with a reduced risk of dementia, particularly among individuals with modifiable risk factors. These findings support beverage substitution as a simple, targeted strategy for mitigating the risk of dementia.