Iron status and cognitive performance in adolescent females

Abstract

Study group from high schools in the Thunder Bay Region (Northwestern Ontario).

Cognitive impairments have been associated with iron deficient anemic infants and young children. The relationship in individuals with only a deficit in their iron stores is less clear. Adolescent females are particularly at risk for being iron deficient, however, the research on the relationship between iron status and cognition in adolescent females is limited. Iron supplements have been frequently used to improve iron status and findings suggest they may also improve cognitive impairments. The purpose of this study is to examine the relationship between iron status and cognition in a group of Canadian, adolescent females. Twenty-one, 14-16 year old, iron deficient (ferritin < 20 pg/1 and hemoglobin > 120 g/1) but non-anemic adolescent females participated in an 8-week, double blind, randomized controlled trial. One hundred milligrams of ferrous gluconate (2 X 50 mg) was administered daily to participants randomly assigned to the active group (N=12). ). The control group (N=9) was administered a placebo. Participants completed the Trail Making Test A and B, Motor Free Visual Perception Test-111, Digit Span, and the Covert Orienting of Visual Attention Task before and after the supplementation period. A 3-day dietary analysis was also conducted pre and post treatment. Cognitive deficits were not apparent pre supplementation and performance was not significantly different between the groups post supplementation. Also, ferritin levels improved in both groups. This study does not support previous findings of a relationship between low iron status and cognitive impairment. The lack of cognitive impairment at the pre-test and the difference between brain iron stores and systemic iron stores may be plausible explanations for the failure to find a relationship between iron status and cognition in this study.