High Intake of Ultra-Processed Foods Associated With Dementia Risk

Consumption of ultra-processed foods increases the risk of developing dementia by 25%, according to study findings published in Neurology.

Researchers conducted a prospective, cohort study to analyze the relationship between ultra-processed foods and dementia using the United Kingdom Biobank database containing health information of 502,507 people in the country from 2006 to 2010. For the study, the researchers included 76,444 people from the Biobank 55 years of age and older who did not have dementia at baseline.

Between 2009 and 2010, study participants completed the Oxford WebQ at baseline and those that provided email addresses were able to repeat the questionnaire 4 times every following 3 to 4 months from 2011 to 2012. The Oxford WebQ assessed dietary intake for up to 206 types of food and 30 drinks over a 24-hour period prior to completion. The researchers used the average of 2 valid, completed questionnaires to represent usual dietary intake for 72,083 respondents who successfully followed-up.

They ascertained the diagnosis of dementia, especially the progression to Alzheimer disease (AD) and vascular dementia, using hospital admission data and death registry records. During the follow-up period, participants experienced 518 first incident dementia events — 287 related to AD and 119 related to vascular dementia.

After analyzing the dietary assessments in individuals who developed dementia vs those who did not, the researchers observed that every 10% increase in consumption of ultra-processed foods correlated with a 25% higher risk for overall dementia (hazard ratio [HR], 1.25; 95% CI, 1.14-1.37), a 14% higher risk for AD (HR, 1.14; 95% CI, 1.00-1.30), and a 28% risk for vascular dementia (HR, 1.28; 95% CI, 1.06-1.55).

People who altered their diet to replace this 10% of ultra-processed foods with minimally processed or unprocessed foods demonstrated a 19% lower risk of developing dementia (HR, 0.81; 95% CI, 0.74-0.89). The researchers also noted that replacing 20% of ultra-processed food weight with an equal amount of minimally processed or unprocessed food led to a 34% lower risk for dementia and 39% lower risk for vascular dementia. However, this substitution did not change AD risk.

“This extends a growing body of evidence to support the adverse effects of an intake of [ultra-processed foods], especially on brain health,” the researchers stated. “Considering that global aging increasing the risk of dementia, our current study provides evidence based on dietary changes to prevent dementia.”

Study limitations included possible exposure misclassification for certain processed foods, residual and unmeasured confounders, and use of a 24-hour dietary assessment which introduces regression dilution to the study. Additionally, overlooking milder dementia cases, selection bias due to the predominance of educated, older, white, women participants, and problems with memory recall regarding 24-hour dietary intake in people with developing dementia may have affected study results.