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'Golden' Rice

    What is golden rice?

    Golden rice

    Golden rice is the result of an effort to develop rice varieties that produce provitamin-A (beta-carotene) as a means of alleviating vitamin A (retinol) deficiencies in the diets of poor and disadvantaged people in developing countries. Because traditional rice varieties do not produce provitamin-A, transgenic technologies were required.
    Through the work of two European scientists, Dr. Ingo Potrykus of the Swiss Federal Institute of Technology in Zurich and Dr. Peter Beyer of the University of Freiburg in Germany, rice plants were developed containing two daffodil genes and one bacterial gene that carry out the four steps required for the production of beta-carotene in rice endosperm. Endosperm is the nutritive tissue surrounding the embryo of a seed and makes up the majority of the rice grain that we eat. The resulting plants appear normal except that after milling (to remove the brown bran), their grain is a golden yellow color due to the presence of provitamin-A (Toenniessen 2000).

    Source: Morten Lillemo,
    Agricultural University of Norway

    How does golden rice produce provitamin-A?
    Provitamin-A is not produced by traditional rice varieties. However, geranylgeranyl diphosphate (GGDP), a compound naturally present in immature rice endosperm, with the help of several enzymes not normally found in rice can be used to produce provitamin-A (Ye et al. 2000).

    Source: www.turtlebackinn.com

    Two genes from daffodil and one from the bacterium Erwinia uredovora were inserted in the rice genome. These three genes produce the enzymes necessary to convert GGDP to provitamin-A. The inserted genes are controlled by specific promoters such that the enzymes and the provitamin-A are only produced in the rice endosperm (Toenniessen 2000).

    When golden rice is ingested, the human body splits the provitamin-A to make vitamin A. For a more detailed explanation of the production of provitamin-A by golden rice, click here.

    Why is vitamin A important?
    According to the World Health Organization (WHO), vitamin A deficiency (VAD) is the leading cause of preventable blindness in children. For children, a lack of vitamin A causes severe visual impairments and blindness and significantly increases the risk of severe illness, and even death, from common infections such as diarrhea and measles. Pregnant mothers are also affected by VAD. VAD in pregnant women causes night-blindness and may also be associated with higher mother-to-child HIV transmission rates as well as increased risk of maternal mortality. WHO estimates between 100 and 140 million children are vitamin A deficient. An estimated 250,000 to 500,000 children with VAD become blind every year and half of those children die within a year of losing their sight (World Health Organization 2002).

    How much vitamin A will golden rice deliver?
    One of the major arguments from opponents of golden rice is that it will not provide enough vitamin A to benefit those who are deficient. A statement from the organization Greenpeace "Genetically Engineered 'Golden Rice' is Fool's Gold", calculated that an adult would have to eat 3.7 kilos (8 pounds) of dry weight golden rice, approximately 9 kilos (20 pounds) of cooked rice, to meet the daily need of vitamin A from golden rice. A breast-feeding woman would have to eat at least 6.3 kilos (14 pounds) dry weight or nearly 18 kilos (40 pounds) of cooked golden rice per day. Based on these calculations, Greenpeace estimated a normal daily intake of 300 grams (0.7 pounds) of golden rice would at best provide 8% of the vitamin A needed daily. In response to the Greenpeace statement, Dr. Potrykus posted a follow-up which states the amount of vitamin A delivered by golden rice can be determined only when data is available from

  • new rice varieties bred by plant breeders,
  • bioavailability studies to determine how much provitamin-A is readily available for absorption by the body, and
  • nutritional studies on people with VAD.
  • This information can only be obtained once the golden rice trait is transferred to local varieties and produced in quantities sufficient to support necessary field experiments. According to Potrykus, the intent of golden rice is to supplement the diet with vitamin A, not provide 100% of the Recommended Daily Allowance (RDA). Potrykus maintains the goal of golden rice having a beneficial effect on vitamin A-deficient people is realistic with experimental golden rice lines possibly already in the 20-40% RDA range.

    For the full text of Potrykus's statement, see: "Genetically Engineered 'Golden Rice' is Fool's Gold" Response from Professor Ingo Potrykus

    Who "owns" golden rice?
    In a highly debated move, the inventors of golden rice signed an agreement in May of 2000 through a small licensing company (Greenovation, Freiburg, Germany) with Zeneca, the crop protection and plant science business of AstraZeneca. This agreement gave Zeneca an exclusive license to charge for commercial use of the golden rice technology. In late 2000, a merger of the agrochemical division of AstraZeneca and Norvartis's agrochemical and seed business was completed to form the company Syngenta, which now holds the license for the commercial use of golden rice. Also in this agreement, Syngenta supports the humanitarian use of golden rice, as intended by the inventors, for developing countries. The agreement defines humanitarian use as individuals receiving $10,000 or less income from golden rice (Potrykus 2001). The agreement also applies to all subsequent applications of the technology to other crop plants. The inventors claim this move was essential to ensure further development of golden rice and timely release of the technology to those who most need it. Arguments for and against the agreement with AstraZeneca (now Syngenta) and an explanation by Potrykus on the need for the agreement can be found at http://www.biotech-info.net/golden.html.

    How will golden rice get to those who need it?

    Subsistence farmes plowing a field.
    Source: www.catholicrelief.org

    In order to fulfill the inventors' goal of helping prevent vitamin A-deficiency in the poor and disadvantaged of developing countries, golden rice has to reach subsistence farmers free of charge and restrictions. Co-inventor Ingo Potrykus has outlined a strategy to get golden rice to poor farmers. As of March 2001, golden rice consisted of a series of provitamin-A producing laboratory lines whose traits must be transferred to locally adapted varieties in rice-growing countries.

    A "Golden Rice Humanitarian Board" was established to determine which institutions would initially receive golden rice, and to ensure that all regulations concerning the handling and use of genetically modified organisms (GMOs) would be followed. Currently, the Humanitarian Board has two partner institutions in the Philippines, four in India, two in China, one in Vietnam, one in Indonesia, and one in Africa. As of July 2002, the Board was also in discussions with two institutions in Latin America (Potrykus 2002). The institutions will be responsible for evaluating the need for golden rice, analyzing and comparing the pros and cons of alternative measures, and setting a framework for the implementation of 'golden rice' that best suits the needs of the areas the institutions serve. In addition, bioavailability (the degree that the provitamin-A is readily available for absorption by the body), substantial equivalence (measures whether a biotech crop or food has similar health and nutritional characteristics to a conventional counterpart), toxicology, and allergenicity assessments will be conducted. The institutions will also be responsible for transferring the trait into the best locally-adapted lines by traditional breeding practices and direct-transformation techniques, as well as ensuring the varieties used will be important to the poor, and not fashionable varieties for the middle class. For the details of Potrykus's strategy, see "Golden Rice and Beyond"

    Will golden rice be accepted?
    Although the inventors of 'golden rice' claim that the technology can ultimately contribute to the reduction of vitamin A deficiency in many poor and disadvantaged people, a number of organizations oppose its implementation. Some claim that 'golden rice' is a proverbial 'Trojan horse' that uses our sympathy for the poor and disadvantaged to gain acceptance for genetically modified crops. Others feel that 'golden rice' will not be able to provide vitamin A in levels that will be beneficial, or that malnutrition will prevent the vitamin A that is available from being absorbed by the body. Another opinion is that even if 'golden rice' could help prevent VAD, it would not be socially accepted by cultures that value a white colored rice. For articles addressing some of the arguments against 'golden rice' as well as responses to the articles from supporters of the technology, visit the web pages in the Additional Resources section below.

    Additional Resources

    Contains a list of articles and responses on golden rice, including several letters from the co-inventor of 'golden rice' Dr. Ingo Potrykus. http://www.biotech-info.net/golden.html

    Grains of delusion: Golden rice seen from the ground. February 2001. An article written and published by: BIOTHAI (Thailand), CEDAC (Cambodia), DRCSC (India), GRAIN, MASIPAG (Philippines), PAN-Indonesia and UBINIG (Bangladesh) which oppose the implementation of golden rice. http://www.grain.org/publications/delusion-en-p.htm

    Golden Rice- A Golden Chance for the Underdeveloped World. by Michael Fumento. American Outlook, July-August 2001. An interview with co-inventor Dr. Ingo Potrykus. http://www.fumento.com/goldenrice.html

    Jason Sutton in the Department of Bioagricultural Sciences and Pest Management at Colorado State University contributed the content for this page.

Page last updated : March 11, 2004

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