Relating Iron Intake to Iron Status and Cognitive Functioning, Results from a 6-month Efficacy Trial Involving Biofortified Pearl Millet in India

Abstract

Objectives: Iron plays a key role in neurophysiology and iron deficiency, a highly prevalent issue worldwide, has been related to impaired cognitive functioning (CF). The current work explores the potential of iron intervention, via pearl millet (PM), to improve the iron status and CF of Indian adolescents. Methods: A subset of subjects (n=127; 12-16y; 55 F, 54% iron-deficient at baseline) performed tests of CF before and after 6 months of PM consumption. Three speeded tests were administered: 1) Simple Reaction Time (SRT), a test of perceptual processing speed, 2) Go/No-Go (GNG), a test of inhibitory control and 3) Attentional Network Task (ANT), a test of three critical functions of attention. Relations between iron intake after 3 or 6 months and changes in hemoglobin, ferritin, and body iron as well as changes in CF were explored using mediation models, where appropriate. Results: Iron intake after 3 months was positively related to change in hemoglobin (p<0.001) and body iron (p=0.05) and in performance on GNG and ANT subcomponents (p<0.05). Hemoglobin change after 3 months was positively related to change in SRT and ANT performance (p=0.03). Change in hemoglobin mediated the relation between iron intake and ANT performance. An improvement in body iron after 6 months was related to improvement in performance on all CF tasks (p<0.05). Conclusions: Our findings support iron intervention via PM as an effective strategy to improve iron status and CF, and expand the understanding of the role iron plays in CF during adolescence.