Increases in adherence to a simplified Mediterranean diet predicts improved next day cognitive functioning

Abstract Background Although differences in adherence to a Mediterranean diet (MD) have been linked to cognitive aging over extended periods of time, little is known about how day-to-day fluctuations in this health behavior may influence micro-longitudinal changes in cognition. Our study examined how increases in daily adherence to a simplified Mediterranean diet (sMD) impacted next day cognitive functioning over the course of 1 week. Purpose This study examined the extent to which dynamic, day-to-day changes in sMD predicted subsequent changes in daily cognitive functioning for middle-aged and older adults. Methods Participants (N = 217, Mage = 54 ± 15, 65% female) completed daily surveys and cognitive tasks over 1 week to measure their daily adherence to the sMD and their daily cognition. Lagged multilevel models assessed the impact of (within-person centered) daily sMD on next day cognition including: episodic memory, executive functioning, and processing speed. Age, sex, race, and education were controlled in all models. Results Results showed that on days following higher than participants’ usual adherence to the sMD, they had faster processing speeds (shorter latencies; γ = −43.85, P .001) and improved executive functioning (γ = 0.47, P = .039) than on days after lower than usual sMD adherence. Conclusion These findings show that day-to-day shifts in sMD adherence have implications for micro-longitudinal changes in cognition for middle-aged and older adults, suggesting even small changes in sMD could add up and contribute to healthy cognitive aging over time. Simple changes such as increasing fruit, vegetable, and fish intake and reducing sugar-sweetened beverage consumption may thus result in improved cognitive functioning over even very brief time periods.