Association of cognitive function with nutritional zinc status in adolescent female students

Abstract

Background and Objective: Zinc deficiency has been recognized as a crucial public health issue, especially among younger adults in developing countries. Therefore, the main objective of this study was to assess the correlation of serum zinc concentrations and dietary zinc intake with cognitive function scores in high school female students. Methods: A sample of 100 students participated in this cross-sectional study. Each participant completed a 3 day 24-h food recall questionnaire to assess the daily zinc intake. We assessed serum zinc status using flame atomic absorption spectrometry technique. Cognitive function was obtained by summing the scores of five tests including Raven’s Standard Progressive Matrices test (RPM) on non-verbal intelligence, Benton visual retention test, Wechsler memory scale, Bonnardel accuracy test and letter eliminating test. Results: The mean of zinc intake and zinc serum level were 9.49±2.08 mg/day, 105.51±31µg/dL respectively. The mean scores on Raven’s RPM, Benton’s, Wechsler’s, Bonnardel’s and letter eliminating tests were 91.44±11.8, 6.8±1.8, 84.64±11.2, 46±6 and 44.84±5.2  respectively. None of the participants reached the ceiling performance. IQ and Memory tests were strongly correlated (p ≤ 0.001). After adjusting the basic variables, strong positive correlations between serum, but not dietary zinc levels, and Raven’s, memory, Bonnardel’s and letter eliminating scores (p<0.001 for all) were detected.  Memory scores were marginally correlated with serum zinc concentrations (p=0.05). Conclusion: Our findings indicate that serum zinc levels are positively correlated with various aspects of brain cognitive function in young female students.