Association of Egg Intake With Alzheimer's Dementia Risk in Older Adults: The  Rush Memory and Aging Project.

Yongyi Pan, 2024 May,  Association of Egg Intake With Alzheimer's Dementia Risk in Older Adults: The  Rush Memory and Aging Project, J Nutr, DOI: 10.1016/j.tjnut.2024.05.012

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder, with 
increasing prevalence due to population aging. Eggs provide many nutrients 
important for brain health, including choline, omega-3 fatty acids, and lutein. 
Emerging evidence suggests that frequent egg consumption may improve cognitive 
performance on verbal tests, but whether consumption influences the risk of 
Alzheimer's dementia and AD is unknown.

OBJECTIVE: To examine the association of egg consumption with Alzheimer's 
dementia risk among the Rush Memory and Aging Project cohort.
METHODS: Dietary assessment was collected using a modified Harvard 
semiquantitative food frequency questionnaire (FFQ). Participants' first FFQ was 
used as the baseline measure of egg consumption. Multivariable adjusted Cox 
proportional hazards regression models were used to investigate the associations 
of baseline egg consumption levels with Alzheimer's dementia risk adjusting for 
potential confounding factors. Subgroup analyses using Cox and logistic 
regression models were performed to investigate the associations with AD 
pathology in the brian. Mediation analysis was conducted to examine the 
mediation effect of dietary choline in the relationship between egg intake and 
incident Alzheimer's dementia .

RESULTS: This study included 1024 older adults (mean [±Standard Deviation] age = 
81.38 ± 7.20 y). Over a mean (±SD) follow-up of 6.7 ± 4.8 y, 280 participants 
(27.3%) were clinically diagnosed with Alzheimer's dementia. Weekly consumption 
of >1 egg/wk (Hazard Ratio = 0.53; 95% Confidence Interval: 0.34, 0.83) and ≥2 
eggs/wk (HR = 0.53; 95% CI: 0.35, 0.81) was associated with a decreased risk of 
Alzheimer's dementia. Subgroup analysis of brain autopsies from 578 deceased 
participants showed that intakes of >1 egg/wk (HR = 0.51; 95% CI: 0.35, 0.76) 
and ≥2 eggs/wk (HR = 0.62; 95% CI: 0.44, 0.90) were associated with a lower risk 
of AD pathology in the brain. Mediation analysis showed 39% of the total effect 
of egg intake on incident Alzheimer's dementia were mediated through dietary 
choline.

CONCLUSIONS: These findings suggest that frequent egg consumption is associated 
with a lower risk of Alzheimer's dementia and AD pathology, and the association 
with Alzheimer's dementia is partially mediated through the dietary choline.