Impact of Iron Intake and Reserves on Cognitive Function in Young University Students

Abstract

Iron is a key nutrient for cognitive function. During periods of high academic demand, brain and cognitive activity increase, potentially affecting iron intake and reserves. The present study aimed to investigate the impact of iron levels on cognitive function in a university sample, considering the influence of gender. A cross-sectional study was conducted with 132 university students (18-29 years) from the University of Castilla-La Mancha (Spain). A dietary record was formed through a questionnaire to analyze iron consumption, and blood and anthropometric parameters were measured. The Wechsler Adult Intelligence Scale-IV was used to determine the Intelligence Quotient (IQ), as well as the Verbal Comprehension Index (VCI), Working Memory Index (WMI), Processing Speed Index (PSI), and Perceptual Reasoning Index (PRI), to assess cognitive abilities. Among women, the prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) was 21% and 4.2%, respectively. No ID or IDA was found in men. The impact of iron intake on IQ and cognitive abilities was mainly associated with the female population, where a positive association between iron intake, serum ferritin, and total IQ was revealed. In conclusion, low iron intake is related to poorer intellectual ability, suggesting that an iron-rich diet is necessary to maintain the academic level of university students.

Keywords: cognitive scales; dietary iron intake; female; ferritin; iron deficiency anemia; male; university students.

Figure 1

Spearman correlation analysis between TIQ and %RI. Female (a) and male (b) participants were classified into four groups (low-medium IQ and <100%RI; low-medium IQ and ≥100%RI; medium-high IQ and <100%RI; medium-high IQ and ≥100%RI), and the corresponding r coefficient was calculated. Points represent individual participant’s value. * p < 0.05 and ** p < 0.01 significant correlation. IQ, intelligence quotient. RI, recommended intake of iron. n.d. not determined.

Figure 2

Spearman correlation analysis between TIQ and %RI. Female participants were classified into four groups (low-medium IQ and <100%RI; low-medium IQ and ≥100%RI; medium-high IQ and <100%RI; medium-high IQ and ≥100%RI), and the corresponding r coefficient was calculated. Points represent individual participant’s value. * p < 0.05 and ** p < 0.01 significant correlation. IQ, intelligence quotient. RI, recommended intake of iron.

Figure 3

Spearman correlation analysis between TIQ and %RI. Male participants were classified into four groups (low-medium IQ and <100%RI; low-medium IQ and ≥100%RI; medium-high IQ and <100%RI; medium-high IQ and ≥100%RI), and the corresponding r coefficient was calculated. Points represent individual participant’s value. IQ, intelligence quotient. RI, recommended intake of iron. n.d. not determined.

Figure 4

Spearman correlation analysis between serum markers (ferritin and iron) and cognitive indices (TIQ, WMI, VCI, PSI, PRI). The r coefficient is shown within de corresponding graph. Points represent individual participants’ values of the female group with iron intake higher than 100% of the recommended intake.