Association of sugar intake with incident dementia in the UK Biobank: a prospective cohort study

BACKGROUND: Excessive sugar intake has been implicated in increased dementia risk; however, existing studies are constrained by small sample sizes and a primary focus on total sugar, with limited investigation into specific sugar subtypes. This study explores the relationship between sugar intake, its subtypes, and the incidence of dementia. METHODS: We analyzed 172,516 participants from the UK Biobank who completed at least one 24-hour dietary recall (Oxford WebQ). Cox proportional hazards models estimated the hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) for total sugar and its subtypes (free sugar, fructose, glucose, sucrose, maltose, lactose, and other sugars) about the risk of dementia. Sex-stratified analyses were also performed. RESULTS: Higher intakes of total sugar (HR = 1.292, 95 % CI = 1.148--1.453) and free sugar intake (HR = 1.254, 95 % CI = 1.117--1.408) were significantly associated with increased dementia risk. Positive associations were also observed for non-milk extrinsic sugars (HR = 1.321, 95 % CI = 1.175--1.486) and sucrose (HR = 1.291, 95 % CI = 1.147--1.452). These associations were evident in women, with higher intakes of total sugars, free sugars, glucose, sucrose, and non-milk extrinsic sugars independently linked to increased dementia risk, whereas no significant associations were found in men. CONCLUSION: Higher consumption of total sugars, free sugars, sucrose, and non-milk extrinsic sugars confers increased dementia risk, particularly among women.