Breakfast Skipping and Declines in Cognitive Score Among Community-Dwelling Older Adults: A Longitudinal Study of the HEIJO-KYO Cohort

Previous studies outlined the correlation of adverse effects of breakfast skipping with cognitive function. However, the majority of these studies have focused on the short-term effects; to date, the long-term effect of breakfast skipping on cognitive function among older adults remains unclear. In this prospective cohort study of 712 older adults (mean age, 70.8 years), breakfast skipping was defined as skipping breakfast one or more times per week, and declines in cognitive score was defined as decreases in Mini-Mental State Examination (MMSE) score of two or more in the observed period. During follow-up (median, 31 months), 135 of 712 participants developed declines in cognitive score. Poisson regression models revealed that the incidence rate for declines in cognitive score was significantly higher in breakfast skipper (n = 29) than breakfast eaters (n = 683) [incidence rate ratio (IRR), 2.10; 95% CI, 1.28-3.44]. Additional propensity score adjustments related to breakfast skipping from baseline parameters (age, gender, smoking and drinking status, BMI, household income, educated level, depressive symptoms, hypertension, diabetes, sleep medication, physical activity, caloric intake, and baseline cognition) produced consistent results (IRR, 2.21; 95% CI, 1.33-3.68). Sensitivity analysis, when the cut-off value of decreases in MMSE score was changed to three points, suggested a significant and stronger association (IRR, 3.03; 95% CI, 1.72-5.35). Regarding daily intakes of food groups, breakfast skippers consumed a significantly lower amount of vegetables, fruits, and fish than breakfast eaters. In conclusion, our findings suggest that breakfast skipping is longitudinally associated with declines in cognitive score among older adults.