Enriched rice: twice as many intestinal parasitic infections among children


A vast study conducted with 10,000 children in Cambodia shows that consumption of rice enriched with vitamins and minerals increases two-fold the risk of infection by a small intestinal worm. This parasitical disease is harmful to health, as the children affected generally suffer from a lack of iron (with a risk or anaemia and cognitive retard) and retarded growth.

Led by the IRD, the research team called into question type of iron used in enriched rice. The researchers showed that its absorption by the children is insufficient. The iron remains in the intestine, helping the parasite.

A large-scale trial in Cambodia

The consumption of enriched, or “fortified”, rice in iron increases the risk of parasitic infection in children. This is the finding of one of the largest studies on enriched rice conducted in Asia, recently published in the journal PloS ONE. Between December 2012 and July 2013, an international research team, led by IRD, followed just under 10,000 children in Cambodian primary schools, given daily meals based on fortified rice within the framework of the World Food Programme (WFP). Adding nutrients in vitamins and minerals is increasingly common in the countries where the normal diet is insufficient in terms of these nutrients, such as Cambodia, in order to improve the nutritional status and cognitive development of children.

Iron: a « doubled-edged » nutrient

Six times a week, during this six-month period, the children were fed either ordinary white rice (placebo), or one of three types of rice enriched in vitamins (vitamin A, vitamin B12, vitamin B9) and minerals (iron, zinc), administered in a standard manner as part of dietary programmes. In parallel, before, during and after the, trial, the researchers monitored the prevalence among the children of the infection due to a small intestinal worm, called hookworms. The results: in six months, the proportion of children infected doubled among those who consumed one of the three types of fortified rice, from 12% to between 16% and 24% among them. This phenomenon is thought to be due to the poor absorption of the type of iron used to fortify the rice according to the research team. Consequently, the iron remaining in the digestive tract would benefit the parasite!

Small worms, major problems

Hookworms, transmitted by soil and food, affect almost 700 million people in the world, particularly children in emerging countries. When in a larva state, these small worms live in the ground. They penetrate their host via the skin on the feet and then travelviathe blood circulation as far as the intestine, causing a loss of blood and iron through the host’s stools. Infected children generally suffer from retarded growth, altered cognitive development and learning difficulties. Contaminated people also display serious problems of anaemia. In Cambodia, in 2014 the National Demographic and Health Survey and showed that that half of the country’s children under five years of age and 40% of women of child-bearing age were anaemic.

The research must urgently lead to making safe the additional nutrients used as part of food programmes in the world, in particular thanks to a type of iron providing better absorption.

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