Association Between Egg Consumption and Dementia Risk in the EPIC-Spain Dementia Cohort

BACKGROUND: Current evidence suggests that egg composition might have potential neuroprotective effects. Our aim was to determine the association between egg consumption and the risk of dementia in a Mediterranean population. METHODS: This study was carried out in 3 centers from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain Dementia Cohort, i.e., 25,015 participants aged 30–70 years, recruited in 1992–1996, and followed up for a mean of 21.5 years. RESULTS: A total of 774 incident dementia cases were diagnosed and validated, of which 518 were Alzheimer's disease (AD). Data on egg consumption were estimated using a validated dietary history questionnaire at recruitment. Cox proportional hazards models, adjusted for confounders, were used in the analyses. No association was observed between egg consumption and either total dementia [hazard ratio between extreme quartiles (HR(Q4vs.Q1): 1.05; 95% CI 0.85–1.31; p-trend = 0.93)] or AD (HR(Q4vs.Q1) 0.93; 95% CI 0.72–1.21; p-trend = 0.50) risks. After dividing the population by adherence to the relative Mediterranean diet (rMED) score, a borderline inverse association was found between egg intake and both total dementia (HR(Q4vs.Q1): 0.52; 95% CI 0.30–0.90; p-trend = 0.10) and AD (HR(Q4vs.Q1): 0.52; 95% CI 0.27–1.01; p-trend = 0.13) risks within participants with low adherence to rMED score. However, no association was observed in participants with medium and high adherence to rMED score. CONCLUSION: This prospective study suggests that egg consumption is associated with a reduced risk of dementia, and specifically of AD, in the adult population with low adherence to rMED score; whereas it has no impact in subjects with moderate and high MD adherence.