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

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. OBJECTIVES: 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. Participants' first food frequency questionnaire 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 amount 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 brain. 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 (SD)] 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 [HR]: 0.53; 95% confidence interval [CI]: 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 that 39% of the total effect of egg intake on incident Alzheimer's dementia was 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 dietary choline.

Blood Leukocyte DNA Methylation Markers of Periodontal Disease and Risk of Lung Cancer in a Case-Control Study Nested in the CLUE II Cohort.

BACKGROUND: Periodontal disease and DNA methylation markers have separately been associated with lung cancer risk. Examining methylation levels at genomic regions previously linked to periodontal disease may provide insight on the link between periodontal disease and lung cancer. METHODS: In a nested case-control study drawn from the CLUE II cohort, we measured DNA methylation levels in 208 lung cancer cases and 208 controls. We examined the association between 37 DNA methylated CpG sites at three genomic regions, Homeobox 4 (HOXA4), Zinc finger protein (ZFP57) and a lcRNA gene region located in Chr10 (ENSG00000231601), and lung cancer risk. RESULTS: Statistically significant associations with lung cancer risk were observed for all 14 CpG sites from HOXA4 (odds ratio [OR] ranging 1.41-1.62 for 1 SD increase in methylation level, especially within 15 years) and one CpG site on gene ENSG00000231601 (OR=1.34 for 1 SD increase in DNA methylation level). While CpG sites on gene ZFP57 were not associated with lung cancer risk overall, statistically significant inverse associations were noted for six CpGs when restricting follow-up to 15 years (OR=0.73-0.77 for 1 SD increase in methylation level). CONCLUSION: Key methylation changes associated with periodontal disease are also associated with lung cancer risk. For both HOXA4 and ZFP57, that these associations were stronger within 15 years of follow up suggests that they act late in the natural history of lung cancer. IMPACT: Identifying biological pathways that link periodontal disease and lung cancer could provide new opportunities for lung cancer detection and prevention.