Association between Egg Consumption and Dementia in Chinese Adults

Background/Objectives: The association between egg consumption and dementia is unclear. We carried out a population-based case-control study in China to determine the independent association of egg consumption with dementia. Methods: We randomly recruited 233 participants with dementia and 233 without dementia from the community health service clinics and the dementia management system in Guangzhou, China to examine their dietary intakes over the past two years and other risk factors for chronic diseases. Egg consumption was categorised by frequency as Non-consuming/<monthly, Monthly, Weekly, Daily or ≥Twice a day. Results: Participants with dementia, compared to controls, were more likely to consume eggs at Monthly (15.5% vs. 8.6%) but less likely to consume at Daily (28.3% vs. 41.6%). The age-adjusted odds ratio (OR) of dementia was 1.76 (95% CI 1.10–2.84) in participants who consumed eggs Weekly and 4.34 (2.16–8.72) in Monthly consumption compared to Daily. However, no significant associations were found for those Non-consuming/<monthly 1.35 (0.71–2.56) and ≥Twice a day 3.49 (0.83–14.67). After further adjustments, including gender, education, family income, smoking, alcohol consumption, dietary intakes (including red meats, poultry, fish, vegetables and fruits), cardiovascular disease and other co-morbidities, the corresponding ORs were 2.10 (1.10–4.02), 4.82 (1.90–12.27), 0.73 (0.29–1.88) and 4.16 (0.80–21.63), respectively. Among participants who consumed eggs Monthly, Weekly or Daily, an inverse association between egg consumption and dementia was observed; the multiple adjusted OR of dementia was 0.48 (0.30–0.76) per average increment in egg consumption. Compared to Monthly consumption, the OR for Weekly consumption was 0.44 (0.18–1.08) and 0.22 (0.08–0.59) for Daily consumption. Conclusions: This study suggests that Daily egg consumption could help reduce the risk of dementia, while uncertainties regarding the association of non-consuming/<monthly or ≥Twice a day consumption with dementia warrant further research.