Clinical Health Updates

Cognitive functioning improved by correcting anemia in young women

Clinical Question:
Does treatment improve cognitive abilities in young women with iron deficiency anemia?

Bottom Line:
Women with iron deficiency anemia, on average, perform worse on cognitive tests than women who have sufficient iron stores. Treatment over 4 months improved measures of cognitive performance (accuracy), as well as the speed of performing the tasks.

Murray-Kolb LE, Beard JL. Iron treatment normalizes cognitive functioning in young women. Am J Clin Nutr 2007;85:778-787.

Study Design:
Randomized controlled trial (double-blinded)

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. The authors examined the relation between iron status and cognitive abilities in young women. 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). 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.