Eggs Consumption in Relation to Lower Risk of Cognitive Impairment in Elderly: Findings from a 6-Year Cohort Study

To evaluate the longitudinal association of eggs consumption with cognitive function in Chinese elderly.

Prospective cohort study.

9028 participants aged ≥60 years from Zhejiang Ageing and Health Cohort Study without cognitive impairment at baseline survey.

Cognitive function was assessed through the Mini-Mental State Examination (MMSE) at baseline and three waves of follow-up (2015, 2016, and 2019-2020). Data on eggs consumption was collected in the diet habits section within the questionnaire at baseline. Log-binomial regression models with the Generalized Estimating Equations, controlled for an extensive range of potential confounders, were used to evaluate the association and estimate relative risks (RRs).

After 6 years of follow-up, 3266 (36.18%) participants were indicated as cognitive impairment by MMSE at least once. Compared with non-consumers or less-than-weekly consumers, participants consuming 0.1-2.9 eggs/week and 3.0-5.9 eggs/week had 18% (RR=0.82, 95%CI 0.76-0.89) and 9% (RR=0.91, 95%CI 0.84-0.99) lower risks of cognitive impairment respectively, whereas no association was found in those consuming ≥6.0 eggs/week (P=0.32). Moreover, infrequent lower-quantity consumption (1-2 days/week and 0.1-1.9 eggs/day), infrequent higher-quantity consumption (1-2 days/week and ≥2.0 eggs/day), and frequent lower-quantity consumption (≥3 days/week and 0.1-1.9 eggs/day) were associated with better cognitive performance, whereas null association was found among frequent higher-quantity consumers (≥3 days/week and ≥2.0 eggs/day). The sensitivity analyses yielded consistent results to the main analysis.

Limited eggs consumption is prospectively related to a lower risk of cognitive impairment in Chinese elderly.