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Can GM-enhanced nutrition wait?

Tomato crop ready for transporting
Tomato crop ready for transporting

A decade has passed since the first genetically modified crop was introduced to the market. Known as Flavr-Savr™, the crop was a delayed-ripening tomato, which was reported to have extended shelf life and - due to spending more time on the vine before picking - better flavour. But within three years, adverse consumer reaction to GM foods in the US and Europe led to its withdrawal from the market. Yet, despite the publicity and consumer wariness about the safety of GM crops, particularly in the West, genetically engineered food crops continue to be developed. Another decade may pass before trials have been conducted, governments pass the required legislation and these crops are widely grown. However, many believe that the benefits to developing countries of nutritionally enhanced GM crops, for instance, greatly outweigh possible risks.

Whilst the majority of GM crops are currently developed to provide disease or pest resistance or tolerance against abiotic (salt or drought) factors, crops are increasingly being modified for other traits. Fruits such as melon, raspberries and tomatoes have been modified to slow or control ripening, coffee has been modified to be decaffeinated, and GM soya and canola (rape) are already widely grown for their modified oil content. These traits are invariably introduced to benefit industrialised countries. However, research for developing countries is increasingly likely to include nutritional enhancement of staple crops.

Protein-rich potato

In India, a genetically modified potato has been developed by a coalition of charities, scientists, government institutes and industry as part of a 15-year plan to combat malnutrition amongst India's poorest children. The 'protato', as it is known, contains a gene AmA1 from the South American amaranth plant, resulting in an increased protein content of 2.5 per cent. Critics argue that the protein level is still relatively low and insufficient to combat poverty in the region. But for India's largely vegetarian population, even pulses and legumes - which contain between 20-25 per cent protein - can prove expensive for the poor, leaving potato as the staple for many of India's poorest people. As well as increased protein in comparison to other vegetables, the protato has high levels of essential amino acids, lysine and methionine, which are vital to good nutrition and healthy development. The protein-rich potato is currently in the final stages of testing, including analysis to discover if the additional protein is digestible. If approved for consumption, the plan is to introduce the GM-enriched potato into the midday meal for Indian schoolchildren, but it is likely to be some years before this plan comes to fruition.

Ironing out malnutrition

Golden rice could help to reduce vitamin A deficiency, particularly in children (IRRI)
Golden rice could help to reduce vitamin A deficiency, particularly in children
IRRI

Golden Rice, a genetically engineered variety renowned for its ability to produce beta-carotene, has been widely acclaimed by scientists as the answer to vitamin A deficiency in developing countries. Although vitamin A deficiency is widespread in some regions and affects 100 million children under the age of five, iron deficiency is a vastly more pervasive problem, causing impaired mental ability in up to 60 per cent of young children worldwide. Iron deficiency is particularly severe in countries where rice is the staple, as traditional rice varieties contain phytic acid, which prevents the human digestive system from absorbing iron. For many years, efforts to find effective ways to address this problem have included the use of iron supplements and encouraging greater meat intake, but none of these approaches has proved sustainable. Whilst research at the International Rice Research Institute (IRRI) has resulted in the selection of a non-GM iron-enriched variety (IR68144), Swiss scientists - who originally transformed rice to produce beta-carotene - attempted to further improve Golden Rice varieties by adding a gene from French beans to more than double the iron content. Moreover, the iron - present in the grain rather than the bran - is expected to be more readily available during digestion. Golden Rice, which has been offered freely to developing countries, is currently being adapted by IRRI for the Philippines and other countries, and the technology is also being transferred to India, where evaluations continue. For Bangladesh, locally developed rice varieties have been genetically engineered to include, as does Golden Rice, a gene expressed normally in the daffodil flower to produce beta-carotene, although the Bangladesh Rice Research Institute reports that the research is not yet complete.

Billions of people around the world not only suffer from vitamin A and iron deficiency but from other forms of mineral and vitamin deficiency. Zinc, another common mineral deficient in many diets, is vital for healthy development to prevent stunting. Biofortification, the development of staple crop varieties rich in minerals, is the aim of HarvestPlus, a global alliance of research institutions and implementing agencies and one of the Challenge Programmes of the Consultative Group on International Agricultural Research (CGIAR). Whilst transgenic crops are not currently part of the biofortification programme, its leaders believe that "transgenic methods hold great promise for improving the nutrient content of staple foods and speeding up the breeding process over what can be achieved using conventional methods." In the meantime, other biotechnology methods will be employed in breeding nutritionally enhanced crops, including molecular marker assisted breeding and genetic transformation technologies.

Date published: March 2005

 

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