Myth: Genetic engineering will deliver more nutritious crops

05/25/2016 11:00

by Earth Open Source


Truth:   No GM crop that is more nutritious than its non-GM counterpart has been commercialized and GM is not needed for good nutrition

GM proponents have long claimed that genetic engineering will deliver healthier and more nutritious “biofortified” crops. However, no such nutritionally enhanced GM foods are available in the marketplace. In some cases, GM foods have been found to be less nutritious than their non-GM counterparts, due to unexpected effects of the genetic engineering process. 1,2

The much-hyped GM golden rice, which is claimed to be able to alleviate vitamin A deficiency in developing countries, is still not ready for the market and at the time of writing had not yet undergone toxicological testing. Cheap and safe solutions to deficiencies of vitamin A and other nutrients are available now and only lack the modest funding needed to roll out more widely.  ]

GM golden rice: More hype than hope?

The best-known attempt to nutritionally improve a crop by genetic engineering is beta-carotene-enriched GM “golden rice”.3,4    Beta-carotene can be converted by the human body to vitamin A. The crop is intended for use in poor countries in the Global South, where vitamin A deficiency causes blindness, illness, and deaths. However, despite over a decade’s worth of headlines hyping golden rice as a miracle crop, it is still not available in the marketplace.

GM proponents blame excessive regulation and anti-GM activists for delaying the commercialization of golden rice. Bjørn Lomborg, author of The Skeptical Environmentalist, wrote an article in February 2013 stating that golden rice had been delayed for 12 years by “relentless opposition to GM foods” from “rich, well-meaning Westerners”, during which time “about 8 million children worldwide died from vitamin A deficiency”.5

But the real reasons for the delay in deploying golden rice are basic research and development problems. The first golden rice variety had insufficient beta-carotene content and would have had to be consumed in kilogram quantities per day to provide the required daily vitamin A intake.3 As a result, a new GM rice variety had to be developed with higher beta-carotene content.4

Also, the process of backcrossing golden rice with varieties that perform well in farmers’ fields in order to ensure a viable product has taken many years.6,7 A 2008 article in the journal Science said that there was still a “long way to go” in the process of backcrossing golden rice lines into the Indica varieties that perform well in Asian farmers’ fields and are favoured by the Asian market.6

After the publication of Lomborg’s article and another by the Observer newspaper’s science editor Robin McKie,8 in February 2013 the International Rice Research Institute (IRRI), the body responsible for the rollout of GM golden rice, felt it necessary to issue a statement contradicting the claims that golden rice was (a) already available and (b) proven effective. On the latter the IRRI said: “It has not yet been determined whether daily consumption of golden rice does improve the vitamin A status of people who are vitamin A deficient and could therefore reduce related conditions such as night blindness,” adding that studies would need to be conducted in order to find this out.9

All in all, the IRRI expected that it “may take another two years or more” for GM golden rice to be available to farmers.9

Clearly, anti-GM activists and excessive regulation are not responsible for the long delay in the deployment of GM golden rice.

Human trials carried out before toxicological safety testing

At the time of writing, golden rice had not been subjected to basic toxicological testing in animals – testing that is required by the European regulatory system for all GMOs before they can be authorized for human consumption.10 Nevertheless this GM rice was fed to human subjects (adults11 and children12) in experiments conducted by researchers from Tufts University, Boston, MA.

It is important to note that these were not safety studies to look for any effects on health, but efficacy tests to see whether the human subjects assimilated sufficient beta-carotene and converted it to vitamin A. Thus these trials did not reflect the intended conditions of regular consumption of golden rice by the target malnourished population.

The trial in adults involved feeding a single serving of golden rice to healthy human subjects. Butter was given with the rice to enable uptake of the beta-carotene from the digestive tract.11 Yet in real-life conditions, golden rice would only be effective if it were consumed regularly. And malnourished people are by definition not healthy and are highly unlikely to have access to fat (oil or butter) to eat with their rice to allow its effective assimilation.

The feeding of GM golden rice to human subjects, especially young children, in the absence of prior animal toxicological testing was condemned by international scientists as a breach of medical ethics and the Nuremberg Code, which was established after World War II to prevent a repeat of inhumane Nazi experiments on people.13

Breaches of medical ethics and Chinese law

In 2012 a further controversy arose when the journal Nature reported that neither the children on whom the rice was tested, nor their parents or their schoolteachers, knew it was genetically modified. Lack of informed consent to the trial is another serious breach of medical and scientific ethics.14

In the row that followed, the Chinese Centre for Disease Control and Prevention (CDC) conducted an investigation into the trial. The CDC investigation revealed discrepancies over the details of the trial. For example, there was confusion over the amount of GM rice the children ate during the study period.14,12 The affair culminated in three officials being sacked for violating Chinese laws and ethical regulations.14


Solutions to vitamin A deficiency already available

Inexpensive and effective methods of combating vitamin A deficiency have long been available. The World Health Organization’s (WHO) long-standing project to combat vitamin A deficiency uses supplements where necessary, but centres on education and development programmes. These programmes encourage mothers to breastfeed and teach people how to grow carrots and leafy vegetables in home gardens – two inexpensive, effective, and widely available solutions.


Beta-carotene is one of the commonest molecules in nature, being found in abundance in green leafy plants and fruits. There is no need to engineer beta-carotene into rice.

The WHO says its programme has “averted an estimated 1.25 million deaths since 1998 in 40 countries.15 According to WHO malnutrition expert Francesco Branca, these approaches are, for now, more promising approaches to combating vitamin A deficiency than golden rice.6

Vitamin A supplementation enjoys broad support. A review published in the British Medical Journal assessed 43 studies involving 200,000 children and found deaths were cut by 24% if children were given the vitamin. The researchers estimated that giving vitamin A supplements to children under the age of five in developing countries could save 600,000 lives a year. They concluded, “Vitamin A supplements are highly effective and cheap to produce and administer.”16,17

If the resources that have been poured into developing golden rice had been put into such proven programmes, thousands of children and adults could have been saved. As the food writer Michael Pollan wrote in an article for the New York Times entitled “The great yellow hype”, “These ridiculously obvious, unglamorous, low-tech schemes are being tried today, and according to the aid groups behind them, all they need to work are political will and money.18

Pollan suggested that the real value of golden rice lies in its usefulness as a public relations strategy to boost the tarnished image of the biotechnology industry. Pollan wrote that golden rice seemed not so much a solution to vitamin A deficiency as a solution “to the public-relations problem of an industry that has so far offered consumers precious few reasons to buy what it’s selling – and more than a few to avoid it.18

Purple cancer-fighting tomato

The John Innes Centre (JIC) in the UK has developed a purple tomato engineered to contain high levels of anthocyanin antioxidants, which, like many other antioxidants, have cancer-preventing properties. The JIC announced the development of the tomato in 2008 in a press release headlined, “Purple tomatoes may keep cancer at bay”.19 Professor Cathie Martin, who led the research, published an article in the press entitled, “How my purple tomato could save your life”.20

These claims were based on the results of a preliminary small-scale feeding study on cancer-susceptible mice, which found that those fed with the purple tomato had an extended lifespan, measured against control groups fed non-GM tomatoes and a standard rodent diet.21 Yet as one of the researchers pointed out, the study did not test for possible toxicity, so “We’re far from considering a human trial”.22

Meanwhile, anthocyanins are available in abundance in many common fruits and vegetables, including raspberries, blackberries, blueberries, bilberries, blood oranges, red cabbage, red onions, and aubergine (eggplant).

The JIC’s Cathie Martin has argued that tomatoes are consumed by people who might not normally consume many fruits and vegetables.20 It is questionable, however, whether people who are so conservative in their food choices would eat a tomato that looks, in the words of one journalist, “like a cross between an orange and a black pudding23 – let alone a tomato that in most countries will carry a GM label.

In 2010, a year after the JIC announced its purple GM tomato, Italian researchers announced a non-GM tomato with higher-than-usual levels of the antioxidant lycopene.24 Lycopene, like anthocyanin, has anti-cancer properties.

For anyone who wants to derive their anthocyanins from tomatoes instead of the many fruits and vegetables rich in these substances, a non-GM purple tomato with high levels of anthocyanins and vitamin C has been developed.25 In contrast with the JIC’s GM tomato, the non-GM tomatoes received little publicity.

Overall it is important to note that the cancer-prevention properties of antioxidants results from the total level consumed rather than due to the special properties of any one antioxidant. So the benefits of antioxidants can best be achieved with a diet containing a variety of fruits and vegetables. A GM crop engineered with a particular antioxidant offers nothing that cannot be achieved through consumption of natural products rich in antioxidants.

“Biofortified” crops are not a solution to hunger

Most “biofortified” crops, whether produced through GM or conventional breeding, target the poor and hungry in the Global South and focus on one or two nutrients, such as Vitamin A or iron. Even if we assume that GM can produce more crops with high levels of one or two nutrients, some important topics need to be addressed before concluding that biofortifying crops by whatever means is a sensible approach to malnutrition:

  • Malnourished people are hungry not because of a lack of biofortified crops, but because they lack the money to buy food and the access to land on which to grow it. This type of poverty is often due to political conflicts in the country. Another cause is ill-advised development programmes that, in return for foreign loans and investment, have forced countries to convert farmland from growing food for people into growing cash crops for export. These are political and economic problems that cannot be solved by offering a biofortified crop, for which the grower will need to be paid. People who have no money to buy basic food will certainly be unable to buy a biofortified food that has taken millions in investment funds to develop.
  • Malnourished people are not usually deficient in just one or two nutrients, but in many. Focusing on a crop that can deliver one or two nutrients is unhelpful because a balance of nutrients is needed for proper absorption. For example, in order to absorb vitamin A, people need to have enough fat in their diet. This problem would need to be addressed before they could benefit from vitamin A-enriched food.
  • Manipulating nutrients in food is controversial and risky. Dosage is difficult to control and certain nutrients may be needed by one person, yet be excessive and potentially dangerous for the next. Overdosing on vitamin A has been linked in some studies to an increased risk of birth defects26,27 and cancer.28Also, nutritional theory is a fast-moving discipline, with today’s desirable nutrient becoming tomorrow’s suspect ingredient.29

Non-GM biofortified crops are already available


If we assume that biofortified foods are a desirable approach to malnutrition, plenty of non-GM crop varieties are available now that do not present the risks and uncertainties of genetic engineering (see Chapter 6).


In addition, there are ways of adding nutrients to people’s diets that do not involve the considerable expense and timespan of crop breeding. These include a rice fortified with iron and vitamins, which has been reported in a preliminary study to have caused dramatic falls in anaemia and vitamin B1 deficiency in children.30




While GM proponents claim that GM can provide nutritionally enhanced (biofortified) foods, no such GM foods are available on the market.


The most widely publicized example of a GM nutritionally enhanced food, golden rice, has swallowed millions of dollars in research and development money. Yet it has not undergone proper toxicological testing and, after more than a decade, is still not ready for the market. In contrast, tried, tested, and inexpensive means of preventing and curing vitamin A deficiency are successful when applied but under-utilized due to lack of funding.


Aspirational claims of nutritionally enhanced GM crops are a dangerous distraction from the real causes of hunger, which are poverty and a lack of access to land on which to grow food.

If society decides that nutritionally enhanced foods are an important route to food security, it need not wait for expensive GM “solutions”. Conventional plant breeding has already successfully and safely produced many such biofortified foods.



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