Meat consumption and risk of incident dementia: cohort study of 493,888 UK Biobank participants.
Level 3 - non-randomized controlled study
Prospective observational cohort study
PubMed 33748832 · doi:10.1093/ajcn/nqab028
What was done
Researchers investigated the relationship between meat consumption and incident dementia among 493,888 UK Biobank participants. Meat intake was assessed using a baseline dietary questionnaire and repeated 24-hour dietary assessments. Incident all-cause dementia, Alzheimer disease (AD), and vascular dementia (VD) were identified via linked hospital and mortality records over a mean follow-up of 8 ± 1.1 years. Cox proportional hazard models estimated hazard ratios (HRs), and interactions with APOE ε4 carrier status were evaluated.
What was found
Over follow-up, 2,896 incident cases of all-cause dementia, 1,006 cases of AD, and 490 cases of VD occurred. - Each 25 g/day increase in processed meat was associated with higher risks of all-cause dementia (HR: 1.44; 95% CI: 1.24, 1.67; P-trend < 0.001) and AD (HR: 1.52; 95% CI: 1.18, 1.96; P-trend = 0.001). - Each 50 g/day increment in unprocessed red meat was associated with lower risks of all-cause dementia (HR: 0.81; 95% CI: 0.69, 0.95; P-trend = 0.011) and AD (HR: 0.70; 95% CI: 0.53, 0.92; P-trend = 0.009). - Unprocessed poultry and total meat had no significant linear trends. - Linear trends were not statistically significant for VD, though higher categories of processed meat were associated with increased risk. - APOE ε4 increased dementia risk 3- to 6-fold but showed no significant interaction with meat intake.
Why it matters
In a very large population cohort, processed meat intake is linked to increased dementia risk independently of APOE ε4 status, while unprocessed red meat shows an inverse association.
Limits
The observational design cannot establish causality and is subject to residual confounding. Dietary intake relied on self-report. Case identification via hospital and mortality records may miss milder or undiagnosed dementia. The average follow-up of 8 years is relatively short for dementia, leaving potential for reverse causation.
Cited by
- context A recent study found that greater consumption of unprocessed red meat was associated with improved outcomes in people carrying APOE4 single nucleotide polymorphisms.