Lead is a toxic heavy metal that was added to petrol for use in cars until as recently as 25 years ago.
It is particularly harmful to the developing brains of infants, children and teenagers, and the damage it does is irreversible.
The situation becomes significantly worse if people are exposed to a high level of lead at the same time as they are suffering from iron deficiency.
In a recent study, researchers show that fortifying food with iron can produce a striking reduction in blood lead concentration in children exposed to high levels of the metal.
The study involved over 450 children in mining areas in southern Morocco. Mining in the surrounding area meant that children of preschool and school age were exposed to an increased quantity of lead.
At the same time, the level of iron in their blood was relatively low, placing them in a high-risk group.
Depending on their weight, the children were given several white-flour biscuits on a daily basis for a period of four and a half months.
The biscuits were fortified with different iron preparations: some received biscuits containing a specific quantity of iron sulphate, while others received biscuits with sodium iron EDTA or sodium EDTA without iron.
To test the effect of the iron supplements, some children received only placebo biscuits containing no additional iron.
EDTA (ethylene diamine tetraacetic acid) forms stable complexes with iron, aiding its uptake into the bloodstream from the intestines. EDTA can also bind to lead in the intestines, reducing its absorption.
The researchers measured the children’s blood lead concentration and iron status before and after the trial, as well as conducting tests to determine how well the children could solve cognitive tasks.
The result showed that the biscuits fortified with iron did reduce the level of lead in the blood – specifically, by 1/3 with sodium iron EDTA complexes and by 1/4 with EDTA and iron sulphate.
In addition, biscuits with added sodium iron EDTA reduced blood lead concentration from 4.3 to 2.9 micrograms per decilitre. The biscuits also brought about an improvement in the children’s iron status.
Researchers suggest that it is possible to reduce blood lead concentration in exposed individuals with just a short iron intervention. This is hugely significant for public health services.
In addition, as the base level of lead in the schoolchildren in the study corresponds to the worldwide average, the results offer good transferability to other regions and population groups.
Citation: Bouhouch RR, et al. (2016). Effects of wheat-flour biscuits fortified with iron and EDTA, alone and in combination, on blood lead concentration, iron status, and cognition in children: a double-blind randomized controlled trial. American Journal of Clinical Nutrition. Published online. DOI: 10.3945/ajcn.115.129346.
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