Zinc fails to break malaria's strength
Researchers from the Netherlands and the United Kingdom recently discovered that supplementing young Tanzanian children with zinc, whether using single or multi-nutrient combination doses, has no protective effect against malaria. The study's findings were published in the journal PLoS Medicine.
Zinc plays a key role in the human body, helping keep the immune system healthy and in good working order. Past research has also suggested that zinc helps reduce diarrhoea. Researchers from Gambia, the Netherlands, Tanzania and the United Kingdom set out to probe whether zinc supplementation can help fight malaria, particularly as zinc deficiency plagues a majority of African children. If zinc supplementation were feasible, it would help cut malaria deaths in Africa, where 91% of the cases occur, according to figures from the World Health Organization (WHO).
The WHO also state that an estimated 655 000 persons died worldwide from malaria in 2010 and that of these deaths 86% were children under 5 years of age.
But Dr Hans Verhoef of Wageningen University in the Netherlands and the London School of Hygiene and Tropical Medicine in the United Kingdom, in cooperation with colleagues, has discovered that zinc has no impact on malaria protection for young children in Africa. The study carried out four trials - in Burkina Faso, Gambia, Papua New Guinea and Peru - to determine whether it would work.
For the purposes of this study, children were randomly assigned to one of four groups: 1) zinc; 2) zinc and multi-nutrients; 3) multi-nutrients without zinc; or 4) placebo. Of 1 029 children enrolled in the study, 612 children between 6 months and 5 years were eligible to participate. They received daily oral supplements containing one of the four dosages.
The results showed no evidence of a significant effect of either zinc or multi-nutrients alone on the incidence of malaria versus placebo, despite that the occurrence of zinc deficiency was cut by zinc supplementation in the trial. The study also found that multi-nutrient supplementation could have an adverse impact because it increased the risk of malaria in children suffering from iron deficiency. According to the researchers, the incidence rate of malaria in all four intervention groups was very similar, equal to about three episodes a year.
'Despite a high prevalence of zinc deficiency, excellent compliance, and few drop-outs, we found no evidence from this trial that preventive zinc supplementation, alone or with multi-nutrients, reduced rates of febrile attacks of malaria,' write the authors of the study. 'We have presented evidence that multi-nutrient supplementation may increase the risk of malaria in children with iron deficiency, strengthening earlier concerns about the safety of multi-nutrient supplementation in malaria-endemic areas, even in settings with good access to health care and appropriate treatment. When results from all trials are considered together, there is no evidence that zinc interventions can reduce the burden of malaria in African children.'
Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body these parasites multiply in the liver before infecting red blood cells. Symptoms of malaria include fever, headache, and vomiting, and usually appear between 10 and 15 days after the mosquito bite occurred. If it is not treated, malaria can quickly become life-threatening as it disrupts blood supply to vital organs. In many parts of the world, the parasites have developed resistance to a number of malaria medicines.
Strategies used to control malaria include prompt and effective treatment with artemisinin-based combination therapies, the use of insecticidal nets in high-risk areas, and indoor residual spraying with insecticide to control the vector mosquitoes.
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Document Reference: Veenemans, J,. et al. (2011) 'Effect of Supplementation with Zinc and Other Micronutrients on Malaria in Tanzanian Children: A Randomised Trial'. PLoS Med 8(11): e1001125. doi:10.1371/journal.pmed.1001125
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