Researchers have succeeded in genetically modifying rice to enhance its vitamin A and iron content. Once they have passed the authorisation procedure, these new varieties will be made freely available to local rice farmers for planting.
Especially in underdeveloped countries, where rice is often the only staple food, iron and vitamin A deficiencies contribute to the high rates of mortality and infirmity of mothers and children. Increased availability of these micro-nutrients in rice can help to reduce the scale of these deficiency-related diseases.
This research has been conducted by a working group led by Prof. Ingo Potrykus at the Swiss Federal Institute of Technology (ETH) in Zurich, in collaboration with a group led by Dr. Peter Beyer at the University of Freiburg i. Breisgau (Germany). The newly nutritional benefits will be introduced into several other local rice varieties at the International Rice Research Institute (IRRI) in the Philippines and will be made freely available to local rice farmers for planting.
Conventional rice grains contain a substance (phytic acid) that can prevent the human digestive system from absorbing iron. Furthermore, only the green parts of rice plants (not the grain) contain the vital precursor of vitamin A (beta-carotene). This is why anaemia and vitamin A deficiencies are so widespread in regions where rice is the principal staple food. Small children, who are mainly fed on rice, are particularly prone to these deficiency-related diseases.
Iron deficiency anaemia is considered to be the most widespread deficiency syndrome world-wide. According to UNICEF over 2 billion people suffer from iron deficiency. In underdeveloped countries, 40 to 50% of children under five and over 50% of pregnant women suffer from iron deficiency.(1)
Over 100 million pre-school age children suffer from vitamin A deficiency, as do millions of women of child-bearing age. Vitamin A is essential for the operation of the body's immune system and is responsible for protecting mucous membrane cells. Vitamin A deficiency causes increased risk of infection, night-blindness and, in severe cases, total blindness. Over 1 million children die every year as a result of vitamin A deficiency.(2)
Until now, these deficiency symptoms could be only partially remedied by food supplements or vitamin and mineral enriched foods.
One rice gene has been modified and two new genes, coming from green beans and a specific micro-organism, have been implanted into the rice plants used at the ETH in Zurich. The result is that the iron content of some plants has been doubled. Furthermore, phytic acid can be completely removed from rice seeds by cooking and the iron absorption by the digestive system is thus improved. This is not possible with conventional rice
Due to the introduction of two other genes, the vitamin A precursor (beta-carotene) will now be stored in husked rice. Some genetically modified plant lines contain sufficient pro-vitamin A to satisfy daily vitamin A requirements with 300 g of cooked rice.
EUFIC 1999
- http://www.unicef.org/sowc98/slight5.htm
- http://www.unicef.org/sowc98/slight3.htm
FOOD TODAY 11/1999
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