Association of Ultraprocessed Food Consumption With Risk of Dementia: A Prospective Cohort Study.

Background And Objectives: There has been a growing body of evidence associating consumption of ultraprocessed foods (UPF) with adverse health outcomes including depression, cardiovascular disease, and all-cause mortality. However, whether UPF are associated with dementia is unknown. The authors investigated the associations between UPF and dementia incidence in the UK Biobank.

Methods: We included 72,083 participants (55 years or older) who were free from dementia at baseline and provided at least 2 times 24-hour dietary assessments from the UK Biobank study. Follow-up occurred through March 2021. UPF were defined according to the NOVA classification. Incident all-cause dementia comprising Alzheimer disease (AD) and vascular dementia was ascertained through electronic linkages to hospital and mortality records. Cox proportional hazards were used to estimate the association between the proportion (%) of UPF in the diet and the subsequent risk of dementia. In addition, substitution analysis was used to estimate the risk of dementia when substituting UPF with an equivalent proportion of unprocessed or minimally processed foods.

Results: During a total of 717,333 person-years of follow-up (median 10.0 years), 518 participants developed dementia, of whom 287 developed AD and 119 developed vascular dementia. In the fully adjusted model, consumption of UPF was associated with higher risk of dementia (hazard ratio [HR] for 10% increase in UPF 1.25; 95% CI 1.14-1.37), AD (HR 1.14; 95% CI 1.00-1.30), and vascular dementia (HR 1.28; 95% CI 1.06-1.55), respectively. In addition, replacing 10% of UPF weight in diet with an equivalent proportion of unprocessed or minimally processed foods was estimated to be associated with a 19% lower risk of dementia (HR 0.81; 95% CI 0.74-0.89).

Discussion: In this prospective cohort study, higher consumption of UPF was associated with higher risk of dementia, whereas substituting unprocessed or minimally processed foods for UPF was associated with lower risk of dementia.