The effect of seafood consumption on the memory of post-secondary students in B.C.

Abstract

Background and Purpose: Seafood makes up a significant portion of the diets of people around the world. Especially fatty fish such as salmon and herring, seafood items contain numerous nutritional benefits including omega-3 fatty acids which studies have shown aid in cognition and memory. However, due to natural and anthropogenic sources of pollution, contaminants such as mercury which studies suggest decreases cognitive functioning if consumed in excess bioaccumulate in marine life including various fish and shellfish species. The purpose of this study was to categorize participants into either the “fish” group (more fish than shellfish consumed) or the “same” group (either more shellfish than fish consumed or equal amounts of fish and shellfish consumed) via a seafood frequency questionnaire, and to administer a memory test to the participants to determine whether there is a significant difference in mean memory test scores between the groups. Methods: 31 participants were randomly selected at BCIT to participate in the study. Participation was voluntary and participants were given written and oral instructions on how to complete both the seafood frequency questionnaire and memory test. Memory test scores were based on the length of the longest digit sequence that the participant was able to recite upon hearing the examiner list the sequence. The highest possible score was a 10, while the lowest possible score was a 1. Results: The mean memory test scores of the groups, “fish” (more fish than shellfish consumed) and “same” (either more shellfish than fish consumed or equal amounts of fish and shellfish consumed), were 5.83 and 5.92, respectively. The median memory test scores of the groups, “fish” and ”same”, were both equal to 6. The standard deviations of the groups, “fish” and “same”, were 1.2004901 and 0.9540736, respectively. The ranges of the groups, “fish” and “same”, were 4 (minimum) to 8 (maximum) and 5 (minimum) to 8 (maximum). From the non-parametric Wilcoxon Rank sum test, the P-value was found to be >0.05 at α = 0.05. Conclusion: The results of this study suggest that diets relatively high in fish are neither positively nor negatively correlated with memory. However, the limitations of this study in combination with the various studies that contradict this study’s findings illustrate the need for further research.