Egg Consumption and Cognitive Function: A Systematic Review and Dose–Response Pooled Analysis Exploring Optimal Daily Intake

BACKGROUND: Eggs provide a high amount of protein and micronutrients. However, the effects of egg intake on cognitive function remain inconclusive, and there has not yet been a pooled analysis on this topic. METHODS: statistics. Subgroup analysis and meta-regression were used to assess the impact of ages, follow-up years of longitudinal studies, diet assessment and risk of bias. Sensitivity analyses were conducted to evaluate the robustness, and publication bias was assessed through Egger's tests. Dose-response relationships were explored through a one-stage robust error meta-regression model. This systematic review and meta-analysis were registered at PROSPERO (No. CRD42024613229). RESULTS: We identified 13 longitudinal and 8 cross-sectional studies, comprising 99,453 individuals with 18,893 cases mainly from Asian countries and the United States. Egg consumption closest to 50 g/day was longitudinally linked to a lower risk of cognitive decline (pooled RR = 0.91; 95%CI = 0.83-0.99), and a 'U-shaped' dose-response relationship was also observed at the lowest risks occurring at 50-60 g/day of egg. Stratified by ages, follow-up years, study population and egg intake assessment, the similar 'U-shaped' relationships were also observed. No publication bias was detected. CONCLUSION: One egg/day (50-60 g/day) is necessary to maintain healthy cognition function in elderly, which may be an effective food therapy to alleviate cognitive decline.