Iron supplements can improve the cognitive performance of even mildly iron-deficient women, according to data presented at the Experimental Biology meeting in Washington DC.

John Beard, Laura Murray-Kolb and colleagues from Pennsylvania State University tested the attention, memory and learning capacity of women aged 18–35. According to Beard, “The iron-deficient women took longer to do tasks and were less successful.” The performance of anaemic women was even worse. “The number of errors in a memory task was double than in the iron-sufficient group” (New Scientist, 20 April).

“The good news is that replacement does help functioning return to normal,” Murray-Kolb told WebMD (19 April). The performance of iron-deficient women who took 60 milligrams of iron every day improved after four months. “It was a highly significant improvement, which is really the proof of the pudding,” said Beard (New Scientist).

Iron deficiency is linked to altered brain chemistry in rats, and the team from Penn State suggest that a similar effect could underlie the impaired cognitive ability of women that lack this essential mineral. Beard told New Scientist that “Iron deficiency could have an adverse impact on the brain by affecting the dopamine and serotonin neurotransmitter systems.” Boosting iron levels might normalize production of these chemical messengers, thereby maximizing the efficiency of learning and memory.

“Women need to know this actually is affecting their brain and the way they're thinking,” said Murray-Kolb (HealthDayNews, 19 April). But she cautions against rushing out to the pharmacy. Women with normal iron levels will not benefit from supplements, and excess iron can be harmful to the heart and liver.