The centres of population in Africa, India and Asia are suffering nowadays from the same environmental problems as Europe and America around 20 years ago: leaded motor fuels and unfiltered factories contaminate the air with enormous amounts of pollutants in the course of industrialisation and urbanisation. The effects on health are especially great in the poor suburbs where there is no purified running water. Children, who put their hands to their mouths more often than adults, ingest enormous amounts of pollutants. It is estimated that about three quarters of all children in the developing countries suffer from an excessive lead content in their bodies and consequently run the risk of neuro-cognitive damage.

Michael Zimmermann from the Institute of Food Science and Nutrition at ETH carried out a study in one of these regions last year, and this was published recently (1). He tested iron-enriched rice on 134 children at a primary school in Bangalore. The aim was to determine whether and to what extent the lead content would decrease as a result of the iron intake. In fact lead and iron are carried through the digestive tract by the same molecule – a substance that is depleted if there is an iron deficiency in the body. Therefore a treatment to remedy the iron deficiency ought to help to excrete lead.

Two thirds less harmed by lead

A proportion of the children were given a mid-day meal including iron-enriched rice for a period of 16 weeks. A control group received the same meal with ordinary rice. The children were between five and nine years of age. They all suffered from iron deficiency, and some of them also from the anaemia caused by this deficiency. The meal of rice corresponded to the menus that are traditional in the region, and the children were allowed to choose between tomato rice, lemon rice and vegetable rice.

The result: what is known as the prevalence, the percentage of children suffering from an excessively high lead level, fell from 65% to 29%, and also only 29% of the children still suffered from iron deficiency instead of 78%. On the other hand the number of children in the control group with an excessive lead content and iron deficiency decreased only slightly as a result of the meal that was offered daily. Zimmermann concludes from this that rice fortified with iron could give lasting support to the efforts to reduce the lead burden.

“However, this is only a by-product of our research,” explains Zimmermann. His primary aim and that of his team was to enable the manufacture of iron-fortified rice at all. The reason is that not only is rice the basic foodstuff for an estimated one third to one half of the world’s population, but also it was up to now the only cereal that could not be enriched.

Normal rice compared to iron-enriched rice. The latter was developed by ETH nutritional scientists. (Photo: Diego Moretti) large

Indian children take part enthusiastically in the ETH study with the new rice. large

The main reason for this was colour: Foodstuff technologists have learned from experience that to be accepted by everyone, the appearance of the treated foodstuff must be exactly identical to the untreated. This means that rice must be white. Even the tiniest colour differences would be perceived as impurities by the people who are most in need of the enriched foodstuff. However, producing white iron turned out to be extremely difficult. Michael Zimmermann and his team worked for three years on the task of converting iron into a readily absorbable, soluble substance.

Economically attractive

The iron powder developed in this way is blended into rice flour. The mixture is pressed into grains that look exactly like natural rice grains. These grains are then mixed into the natural rice in the ratio of 1 to 50.

The rice flour is obtained from the rice wastes that are produced in rice mills, therefore the process is particularly economical. The Swiss company group Bühler, which specialises in plant and process technology to process various types of cereal, has developed a machine to manufacture this iron-enriched rice and is already selling it in China at the present time.

Meanwhile at ETH they are already thinking further ahead. The aim now is both to enrich rice with other nutrients and to find other foodstuffs for the iron powder. This is because iron deficiency is still the world’s most widespread nutritional disease. According to the WHO, it is estimated that two billion people – more than 30 percent of the world’s population – suffer from anaemia, most of them due to iron deficiency. The illness causes enormous damage to national economies by reducing the work capacity of individuals and of entire populations. This is why iron-enriched soy sauce and fish sauce are already available in Vietnam, and iron-enriched salt in West Africa as well.