Iron tablets can improve women's brainpower
11:07 20 April 04
Source: NewScientist.com news service
The brainpower of young women who are lacking in iron can be markedly boosted by taking supplements of the mineral, suggests a new study.
Even women who were just modestly iron deficient did much worse on attention, memory and learning tests than those with enough iron in their blood, found the study by researchers at Pennsylvania State University in the US.
"The iron deficient women took longer to do tasks and were less successful," says John Beard, one of the team. For those classified as anemic the difference was particularly stark, he says: "The number of errors in a memory task was double than in the iron sufficient group." But giving these women daily supplements of iron for four months reversed this effect.
"It was a highly significant improvement, which is really the proof of the pudding," he told New Scientist. "If you give iron and somebody improves you can be pretty sure the iron was causally related in the first place."
"It certainly fits in with everything we suspect about the impact of iron on cognitive performance," says Durhane Wong-Rieger, president of the Anemia Institute in Toronto, Canada. "This study may be a very important step towards not only understanding, but maybe reversing the situation for iron deficient women."
Malaise and lethargy
It is well-documented that iron deficiency may harm cognitive performance and development in infants, say Beard and Wong-Rieger. But anecdotal reports of iron deficient young women experiencing malaise and lethargy prompted the Penn State team to investigate this age group.
They believe their study is the first to show how iron supplementation can reverse the impact of deficiency on cognitive performance.
The study followed 113 women aged 18 to 35, divided into three groups. Following World Health Organization guidelines, women with less than 120 grams/litre haemoglobin in their blood were classified as anaemic. Those with levels between 120 and 125 g/l were considered iron deficient, and those exceeding 125g/l were considered iron sufficient. The team also measured at blood ferritin levels, an index of iron storage in the blood.
Iron deficient women did worse and took longer to complete the computer-based tasks. But after four weeks, those women taking iron significantly improved their performance compared to those taking a placebo. Blood tests confirmed their iron levels had also improved.
The team believe their work is important because iron deficiency is very common among women of reproductive age due to blood loss during heavy menstruation. Beard says about 15 to 18 per cent of US women in this group are iron deficient - between eight and 10 million women.
However, he cautions that women of Anglo-Saxon origins should not rush to take iron supplements without proper medical examination. This is because about one in 20 people of Anglo-Saxon origin carry a gene for "iron overload" or heredity haemochromatosis.
Iron deficiency could have an adverse impact on the brain by affecting the dopamine and serotonin neurotransmitter systems, Beard suggests.
Iron deficiency in developing infants can mean the fatty myelin sheaths that wrap nerve cells and help them to conduct do not form properly. And previous studies in infants have shown the speed of nerve signals is slower in iron deficient children, says Beard.
The results were presented at the Experimental Biology 2004 meeting in Washington DC on Monday.