GM Free Cymru

Golden Rice: A dangerous experiment

In February 2009 a group of 22 international scientists and experts addressed an open letter to Prof Robert Russell at Tufts University School of Medicine, who is in charge of clinical trials on GM Golden Rice, protesting at clinical trials of GM Golden Rice being conducted on adults and children.[1]

The authors say that the trials breach the Nuremberg Code, brought in at the end of World War II to prevent any repetition of the experiments conducted on people by Nazi scientists.

The authors say that Golden Rice:

* is inadequately described in terms of biological and biochemical makeup

* has not been shown to be stable over time – GM crops have been found to be unstable in that their genetic makeup as revealed in tests has differed from that described by the company and scrambling of the genome at the site of insertion sometimes occurs[2]

* has never been through a regulatory /approvals process anywhere in the world.

The authors’ concerns are backed by a large body of evidence showing that GM crop/food production produces unintended effects, which can result in damage to health when GM foods are fed to animals.[3] There is no evidence to suggest that Golden Rice is any safer than these GM foods.

The authors of the letter to Prof Robert Russell protesting at the Golden Rice human feeding trials conclude, “We can assure you that such trials would not have been approved within the European Union in the absence of safety information, which highlights yet again the flaw of the USDA and FDA regulatory system in considering GM crops/foods as hypothetically “generally recognised as safe – GRAS” in the absence of hard experimental data.”

This is not the first time that clinical trials of Golden Rice have become mired in controversy. In the summer of 2008 it was reported that a clinical trial on Golden Rice was cut short in China in July 2008, when the government found that 24 children 6-8 years of age at a primary school in Henyan, Hunan, were to be used as guinea pigs.[4]

Golden Rice not proven safe to eat

When pharmaceutical drugs are tested for safety, they are first tested on animals. Only if animal studies reveal no harmful effects is the drug further tested on human volunteers. If animal tests with a drug were to yield results similar to those seen in feeding studies carried out with GM foods, the drug would most likely be disqualified for further development. Golden Rice has never been subjected to feeding trials on animals. It is therefore criminally irresponsible to test it on humans.

The absence of animal testing data on Golden Rice is especially worrying as Golden Rice is engineered to overproduce beta carotene, and studies show that some retinoids derived from beta carotene are toxic and cause birth defects.[5][6][7][8][9] In particular, high concentrations of the retinoid called retinol are toxic.[10]

One of the breakdown products of beta-carotene, RA, is biologically active at much lower concentrations than retinol, and for this reason excess RA or RA derivatives are extremely dangerous, particularly to infants and during pregnancy.[11]

In his review of GM nutritionally enhanced plants, David R. Schubert of Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California, argues that “rigorous, multigenerational animal safety assessments with the hope of identifying risks to health” are needed for all such plants before they are commercialized.[12]

Defenders of Golden Rice have claimed that as humans and not animals are the intended consumers, animal feeding trials are unnecessary.

This argument is a common one from advocates of GM, but it is fatally flawed. It is true that animal feeding trials on Golden Rice may not answer the questions of how much vitamin A humans would derive from eating the rice and how effective it would be in solving vitamin A deficiency in humans. But when it comes to testing for toxic effects, animal feeding trials have been found to be a valuable indicator.

It is especially important to carry out such toxicological testing on GM foods because unexpected toxins or allergens may arise from the GM process itself. These may result from genetic disruptions or disturbed biochemistry arising from new enzyme activities in a place where they do not normally occur. The same enzyme working in different plant hosts and cellular environments, as is the case with Golden Rice, can participate in different biochemical reactions – and produce by- products that affect health.

For these reasons, animal testing is the standard investigation performed to assess possible toxicity both in drugs and in new GM foods. Why should Golden Rice be an exception?

With regard to testing for efficacy and assimilation of the beta- carotene in Golden Rice, defenders of the product say that beta- carotene is broken down differently in animals than in humans and so animal testing is irrelevant. But ferrets have been identified by researchers as animals that break down beta-carotene in a similar way to humans.[13] Why has efficacy and assimilation not been tested on them?

Golden Rice appears to have escaped animal testing because of the pervasive attitude to GM in the USA, which was initiated and perpetuated by industry in partnership with government. Under the US system, GM crops and foods are classed as "GRAS" (Generally Recognised As Safe). This is a completely theoretical evaluation which means that industry can do no safety testing at all and still get products approved.

Tellingly, on the Golden Rice Humanitarian Board website ( ), the header for the section "Tests performed on Golden Rice" reads, "It's just rice". The unnamed authors claim, "Detailed molecular analyses have failed to find new allergens showing up as a consequence of having introduced a new gene into a plant, and determination of the expression levels of ten-thousands of genes have also shown that the only changes encountered are related to the introduced genes and those involved in related metabolic pathways." But no data have been published to enable independent scientists and the public to evaluate these claims. As one scientist told GMWatch, "If data isn't published, it doesn't exist."

Bizarrely, the "Research on Health Effects" section of the Golden Rice website lists publications NOT on Golden Rice but on general research on the health effects of vitamin A. Even more bizarrely, the main publications listed are by the United Nations (UN) and the World Health Organisation (WHO). The UN and WHO report success from their long-running programmes to combat vitamin A deficiency (VAD) in those places where they have been implemented. These tried-and-tested programmes involve cheap, traditional, and readily available solutions such as vitamin A supplements and encouraging home growing of vitamin A-rich leafy green vegetables. Golden Rice has never been a part of these programmes. Yet in a sleight-of-hand that has become all too typical in the GM industry, the Golden Rice Humanitarian Board is using data from those programmes to promote its risky, heavily patented, and expensive technological 'solution' to VAD!

Golden Rice not proven safe for the environment

No data have been published on the environmental risks of Golden Rice. These may include the possibility that the rice will cross-pollinate with other cultivated rice and wild rice.

Golden Rice not proven effective

No data have been published on how much beta-carotene is in the rice after four weeks of storage and 20 minutes of cooking.

It’s important to note that Golden Rice does not contain vitamin A, but a vitamin A precursor, beta-carotene, that needs to be converted by the body into usable vitamin A.

No data have been published on the bioavailability and conversion into vitamin A of the beta-carotene in Golden Rice – how much is actually taken up and converted into a useful nutrient by the body.

No data have been published on the bioavailability and conversion into vitamin A of the beta-carotene in Golden Rice in people who are deficient in other nutrients. The target consumers of Golden Rice are the malnourished, but these people are lacking in many nutrients, some of which (e.g. fats and iron) are necessary for the uptake and use of beta-carotene. This fact undermines the entire “single nutrient” assumption behind the Golden Rice project.

Better alternatives are available

"GE rice could, if introduced on a large scale, exacerbate malnutrition and undermine food security because it encourages a diet based on a single industrial staple food rather than upon the reintroduction of the many vitamin-rich food plants with high nutritional value that are cheap and already available." – Professor Klaus Becker, University of Hohenheim, Germany

“Real-world studies [on Golden Rice] are still lacking, says WHO malnutrition expert Francesco Branca, noting that it’s unclear how many people will plant, buy, and eat golden rice. He says giving out supplements, fortifying existing foods with vitamin A, and teaching people to grow carrots or certain leafy vegetables are, for now, more promising ways to fight the problem.” [14]

WHO launched its strategy to combat vitamin A deficiency (VAD) in 1998. It describes the strategy as follows: [15]

*promoting breastfeeding, as breast milk is a natural source of vitamin A and protects babies from VAD

*supplying high-dose vitamin A supplements for deficient children. This has proven a simple and low-cost intervention that has produced remarkable results, reducing mortality by 23% overall and by up to 50% for acute measles sufferers

*food fortification, which takes over where supplementation leaves off. Sugar fortified with vitamin A in Guatemala maintains vitamin A status, especially for high-risk groups and needy families.

*cultivating the garden is the next phase necessary to achieve long- term results. For vulnerable rural families, for instance in Africa and South-East Asia, growing fruits and vegetables in home gardens enables a diverse diet and contributes to better lifelong health. This is backed by research in South Africa. A home-gardening program that was integrated with nutrition education, and focused on the production of yellow and dark-green leafy vegetables, significantly improved the vitamin A status of 2-5-year-old children in a rural village in South Africa. [16]

Changing agricultural models have contributed to vitamin A deficiency

Interestingly, WHO’s recommended practice of growing beta-carotene- rich leafy vegetables in home gardens was common in developing countries before the arrival of World Bank, IMF and other Western- backed programmes that forced farmers into growing cash crops for export. This fact is recognized in a World Bank report, which notes, “Cash crops are useful for generating income but export vegetables may not be meeting local demand for micronutrient-rich foods.”

The report also says, “Home gardens can be both a major household food resource and a source of income. It recognizes that the role of home gardens in solving nutrient deficiencies have been ignored by policy makers because they lack the status of marketed crops (and often do not appear on any economic balance sheet). Home gardens are also frequently the domain of women, which further reduces their status.[17]

It is ironic that Golden Rice is a “solution” promoted by Western interests to a problem that was arguably generated by Western interests in the first place.


1. Tufts University Involvement in Golden Rice Feeding Trials. Letter from scientists and experts to Professor Robert Russell, Professor Emeritus, Friedman School of Nutrition Science and Policy, Tufts University School of Medicine, February 2009, archived at
2. Collonnier C, Berthier G, Boyer F, Duplan M-N, Fernandez S, Kebdani N, Kobilinsky A, Romanuk M, Bertheau Y (2003). Characterization of commercial GMO inserts: a source of useful material to study genome fluidity.
3. Reviews include: Pusztai A. and Bardocz S. (2006). GMO in animal nutrition: potential benefits and risks. In: Biology of Nutrition in Growing Animals, eds. R. Mosenthin, J. Zentek and T. Zebrowska, Elsevier Limited, pp. 513-540; Schubert D.R. (2008) The problem with nutritionally enhanced plants. J Med Food., 11: 601-605; Dona A. and Arvanitoyannis I.S. (2009) Health Risks of Genetically Modified Foods. Crit Rev Food Sci Nutr., 49: 164–175.
4. Noemie Bisserbe, “Golden scare: A new genetically modified rice strain is breeding controversy”, Businessworld, 22 August 2008,
5. McCaffery PJ, Adams J, Maden M, Rosa-Molinar E: Too much of a good thing: retinoic acid as an endogenous regulator of neural differentiation and exogenous teratogen. Eur J Neurosci 2003;18: 457– 472.
6. Adams J, Holson RR: The neurobehavioral teratology of vitamin A analogs. In: Handbook of Developmental Neurotoxicology (Slikker W, Chang LW, eds.). Academic Press, San Diego, CA, 1998, pp. 631–642.
7. Marcus R, Coulston AM: Fat-soluble vitamins. In: The Pharmacological Basis of Therapeutics, 10th ed. (Hardman JG, Limbird LE, Gilman AG, eds.). McGraw Hill, New York, 2001, pp. 1773–1791.
8. Teelmann K: Retinoids: toxicology and teratogenicity to date. Pharmacol Ther 1989;40:29–43.
9. Wyatt EL, Sutter SH, Drake LA: Dermatological pharmacology. The Pharmacological Basis of Therapeutics, 10th edition (Hardman JG, Limbird LE, Gilman AG, eds.). McGraw Hill, New York, 2001, pp. 1795– 1818.
10. Adams J, Holson RR: The neurobehavioral teratology of vitamin A analogs. In: Handbook of Developmental Neurotoxicology (Slikker W, Chang LW, eds.). Academic Press, San Diego, CA, 1998, pp. 631–642.
11. Marcus R, Coulston AM: Fat-soluble vitamins. In: The Pharmacological Basis of Therapeutics, 10th ed. (Hardman JG, Limbird LE, Gilman AG, eds.). McGraw Hill, New York, 2001, pp. 1773–1791.
12. David R. Schubert, “Perspective: The Problem with Nutritionally Enhanced Plants”, J Med Food 11 (4) 2008, DOI: 10.1089/jmf.2008.0094.
13. Morphology of ferret subcutaneous adipose tissue after 6-month daily supplementation with oral beta-carotene. Incoronata Muranoa, Manrico Morronia, Maria Cristina Zingarettia, Paula Oliverb, Juana Sánchezb, Antonia Fusterb, Catalina Picób, Andreu Paloub and Saverio Cinti. Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, Volume 1740, Issue 2, 30 May 2005, pp. 305-312
14. Enserink, M. 2008. Tough Lessons From Golden Rice. Science, 230, 468-471.
15. Vitamin A deficiency, World Health Organisation website,
16. Faber Mieke; Phungula Michael A S; Venter Sonja L; Dhansay Muhammad A; Benadé A J Spinnler (2002). Home gardens focusing on the production of yellow and dark-green leafy vegetables increase the serum retinol concentrations of 2-5-y-old children in South Africa. The American journal of clinical nutrition 2002;76(5):1048-54.
17. “Best Practices in Addressing Micronutrient Malnutrition” by Judith McGuire, The World Bank, 1818 H Street NW, Washington DC, 20433,

GMWatch May 2009