Iron treatment normalizes cognitive functioning in young women.
BACKGROUND
Evidence suggests that brain iron deficiency at any time in life may disrupt metabolic processes and subsequently change cognitive and behavioral functioning. Women of reproductive age are among those most vulnerable to iron deficiency and may be at high risk for cognitive alterations due to iron deficiency.


OBJECTIVE
We aimed to examine the relation between iron status and cognitive abilities in young women.


METHODS
A blinded, placebo-controlled, stratified intervention study was conducted in women aged 18-35 y of varied iron status who were randomly assigned to receive iron supplements or a placebo. Cognition was assessed by using 8 cognitive performance tasks (from Detterman's Cognitive Abilities Test) at baseline (n = 149) and after 16 wk of treatment (n = 113).


RESULTS
At baseline, the iron-sufficient women (n = 42) performed better on cognitive tasks (P = 0.011) and completed them faster (P = 0.038) than did the women with iron deficiency anemia (n = 34). Factors representing performance accuracy and the time needed to complete the tasks by the iron-deficient but nonanemic women (n = 73) were intermediate between the 2 extremes of iron status. After treatment, a significant improvement in serum ferritin was associated with a 5-7-fold improvement in cognitive performance, whereas a significant improvement in hemoglobin was related to improved speed in completing the cognitive tasks.


CONCLUSIONS
Iron status is a significant factor in cognitive performance in women of reproductive age. Severity of anemia primarily affects processing speed, and severity of iron deficiency affects accuracy of cognitive function over a broad range of tasks. Thus, the effects of iron deficiency on cognition are not limited to the developing brain.
Murray-Kolb
Laura E
LE
Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA. lmurrayk@jhsph.edu
Beard
John L
JL
D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000523:psychology; D001288:Attention / Q000187:drug effects; D003071:Cognition / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D007858:Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects; D018579:Patient Selection; D010919:Placebos; D012016:Reference Values
D010919:Placebos; D007501:Iron