Identifying and characterizing the effects of nutrition on hippocampal memory.

In this review we provide evidence linking relational memory to the hippocampus, as well as examples of sensitive relational memory tasks that may help characterize the subtle effects of nutrition on learning and memory. Research into dietary effects on cognition is in its nascent stages, and many studies have cast a wide net with respect to areas of cognition to investigate. However, it may be that nutrition will have a disproportionate effect on particular cognitive domains. Thus, researchers interested in nutrition-cognition interactions may wish to apply a more targeted approach when selecting cognitive domains. We suggest that hippocampus-based relational memory may be extraordinarily sensitive to the effects of nutrition. The hippocampus shows unique plastic capabilities, making its structure and function responsive to an array of lifestyle factors and environmental conditions, including dietary intake. A major function of the hippocampus is relational memory, defined as learning and memory for the constituent elements and facts that comprise events. Here we identify several sensitive tests of relational memory that may be used to examine what may be subtle effects of nutrition on hippocampus and memory. We then turn to the literature on aerobic exercise and cognition to provide examples of translational research programs that have successfully applied this targeted approach centering on the hippocampus and sensitive relational memory tools. Finally, we discuss selected findings from animal and human research on nutrition and the hippocampus and advocate for the role of relational memory tasks in future research.