Parents, take note! Anaemia may protect your children against blood-stage malaria infection, according to a new study which claims that iron supplements removes this protective effect.
Iron deficiency is the most common nutritional deficiency in the world and causes long-term adverse consequences in children.
However, concerns remain about the safety of iron supplements, particularly for children in malaria-endemic countries lacking adequate access to health services.
Researchers at the University of North Carolina (UNC) at Chapel Hill in the US have proven these concerns valid after finding iron deficiency anaemia actually protects children against the blood-stage of Plasmodium falciparum malaria in Africa and treating anaemia with iron supplementation removes this protective effect.
Researchers studied the red blood cells of 135 anaemic children aged 6-24 months in a malaria-endemic region of The Gambia where sickle-cell trait was also common.
The children received iron through micronutrient powder for 84 days as part of an iron supplementation trial.
Red blood cells from the children were analysed at baseline, day 49 and day 84.
Previous studies had shown a protective effect from malaria in children having the sickle-cell trait.
However, the researchers found that on a population-wide basis anaemia reduced the blood-stage of malaria by 16 per cent while the sickle-cell trait only reduced it by four per cent.
"Our finding that anaemia offers greater natural protection against blood-stage malaria infection than sickle-cell trait has led us to formulate the interesting hypothesis that the widespread prevalence of anaemia in people of African descent is a genetic signature of malaria," said Morgan Goheen from UNC.
Deficits in invasion and growth for blood stage P falciparum were reversed when anaemic children had received seven weeks of iron supplementation.
Prior work by the same research team suggests that the increased invasion and growth rates following iron supplementation are caused by the parasites' strong preference for young red blood cells.
These new field results consolidate the evidence that iron supplementation increases the risk of P falciparum malaria and provide support for the use of malaria prophylaxis by iron supplementation programs, especially during the critical, early phases of the erythroid recovery.
The study was published in the journal EBioMedicine.