Egg Intake and the Incidence of Alzheimer's Disease in the Adventist Health Study-2 Cohort Linked with Medicare Data.

BACKGROUND

A substantial knowledge gap remains regarding the relationship between modifiable dietary factors and Alzheimer's disease risk. Eggs are a source of key nutrients that support brain health.

OBJECTIVES

The aim of this study was to investigate the association between egg consumption and the incidence of Alzheimer's disease.

METHODS

Data were drawn from the Adventist Health Study-2, a large, prospective cohort of United States Seventh-day Adventists, linked with Medicare records to identify Alzheimer's disease diagnosis. Diet and lifestyle factors were assessed using a validated food frequency questionnaire. Egg consumption was categorized by frequency, ranging from never/rarely to ≥5 times per week. The analytic sample included 39,498 participants (mean follow-up: 15.3 y), among whom 2858 developed Alzheimer's disease. Multivariable-adjusted Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted cubic spline analysis was conducted using continuous egg intake (g/d).

RESULTS

Egg consumption was inversely associated with Alzheimer's disease risk. Compared with never/rarely consuming eggs, HRs (95% CIs) after adjusting for demographic, lifestyle, food groups, and comorbidities were 0.83 (0.75, 0.92) for 1-3 times per month, 0.83 (0.74, 0.94) for once per week, 0.80 (0.71, 0.90) for 2-4 times per week, and 0.73 (0.60, 0.89) for ≥5 times per week. In the spline model, zero egg intake was curvilinearly associated with an adjusted HR of 1.22 (1.11, 1.34) compared with 10 g/d.

CONCLUSIONS

In this health-conscious population, moderate egg consumption was associated with a significantly lower risk of Alzheimer's disease. These findings suggest a potential neuroprotective benefit of nutrients found in eggs when consumed as part of a balanced diet.