Association between whole egg consumption and cognitive function in older adults: Birjand longitudinal aging study

Article type: Research Article

Authors: Sajadi Hezaveh, Zohreh^a | Moodi, Mitra^{b; c} | Fakhrzadeh, Hossein^{d; e} | Arzaghi, Seyed Masoud^e | Khodabakhshi, Huriye^b | Khorashadizadeh, Masoumeh^b | Ejtahed, Hanieh-Sadat^{f; *} | Sharifi, Farshad^{e; *}

Affiliations: [a] Department of Health Sciences, Faculty of medicine and health, The University of Sydney, Sydney, New South Wales, Australia | [b] Geriatric Health Research Center, Birjand University of Medical Sciences, Birjand, Iran | [c] School of Health, Birjand University of Medical Sciences, Birjand, Iran | [d] Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran | [e] Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran | [f] Obesity and Eating Habits Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran

Correspondence: [*] Corresponding authors: Hanieh-Sadat Ejtahed, Assistant Professor, Endocrinology and Metabolism Research Institute, Tehran University of Medical Sciences, Tehran, Iran, Tel.: +982188631296; E-mail: [email protected] and Farshad Sharifi, Assistant Professor, Elderly Health Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran, Tel.: +982188631296; E-mail: [email protected].

Abstract: OBJECTIVE:Egg consumption could reduce the chance of cognitive decline. We aimed to assess this possible protective effect using data from the Birjand longitudinal aging study (BLAS). METHODS:In this cross-sectional study, the association between number of whole eggs consumed per week and cognitive impairment was assessed on 1352 participants in the context of the first wave of BLAS conducted on September 2018 to April 2019. Six Item Cognitive Impairment Test (6-CIT), Mini-Mental State Examination (MMSE), Verbal Fluency Test (VFT) and abbreviated mental test (AMT) questionnaires were used to assess the cognitive function. Analyses have been conducted using multiple logistic regression. RESULTS:Participants ate an average of 2.4 eggs per week. Older adults with moderate and high egg consumption (2–3 eggs/week and ≥4 eggs/week, respectively) performed better at 6-CIT (OR: 0.61, 95% CI: 0.46; 0.80; and 0.58, 95% CI: 0.41; 0.82), AMT (0.67, 95% CI: 0.52; 0.87; and 0.56, 95% CI: 0.39; 0.80) and all 4 cognitive tests combined (0.47, 95% CI: 0.30; 0.73; and 0.44, 95% CI: 0.24; 0.78). VFT was not associated, and MMSE score was only associated with high egg intake (0.53, 95% CI: 0.38; 0.74). High egg intake was more protective of cognitive decline (≥40%) than the moderate intake (30–40%). The significance of most associations disappeared after adjustment for confounders and covariates. CONCLUSIONS:In summary, the findings of this study suggest a potential inverse relationship, displaying an ascending trend, between weekly egg consumption and cognitive function among elderly Iranians.

Keywords: Egg, cognitive impairment, dementia, Alzheimer’s disease, elderly

DOI: 10.3233/MNM-230096

Journal: Mediterranean Journal of Nutrition and Metabolism, vol. Pre-press, no. Pre-press, pp. 1-15, 2024