3.9 MYTH:

Genetic engineering will deliver more nutritious crops


No GM crop that is more nutritious than its non-GM counterpart has been commercialised and some GMOs are less nutritious

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.

Examples include:

  • GM soy had 12–14% lower levels of cancer-fighting isoflavones than non-GM soy.119
  • Canola (oilseed rape) engineered to contain vitamin A in its oil had much reduced vitamin E and an altered oil-fat composition, compared with the non-GM control.120
  • Experimental GM rice varieties had unintended major nutritional disturbances compared with non-GM counterparts, although they were grown side-by-side in the same conditions. The structure and texture of the GM rice grain was affected and its nutritional content and value were dramatically altered. The variation ranged from 20 to 74% for amino acids, from 19 to 38% for fatty acids, from 25 to 57% for vitamins, from 20 to 50% for nutritionally important trace elements, and 25% for protein. GM rice varieties variously showed markedly decreased levels of vitamin E, protein, and amino acids. The authors said that their findings “provided alarming information with regard to the nutritional value of transgenic rice” and showed that the GM rice was not substantially equivalent to non-GM.121

3.9.1. Golden Rice: More hype than hope?

The best-known attempt to nutritionally improve a GM crop is beta-carotene-enriched “Golden Rice”.122,123 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 commercialisation of Golden Rice. But the real reasons for the delay seem to be basic research and development problems. The first Golden Rice variety had insufficient beta-carotene content and would have needed to be consumed in kilogram quantities per day to provide the required daily vitamin A intake.122 As a result, a totally new GM rice variety had to be generated with much higher beta-carotene content.123

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.124,125 A 2008 article in the journal Science said that there was still a “long way to go” in the backcrossing process.124

It has taken over a decade to develop Golden Rice. Yet as of 2012, field trials have not been completed to ensure that it grows successfully in local conditions. Nor has it been tested in toxicological feeding trials on animals to establish whether it is safe to eat. Nevertheless, the rice was fed to human subjects (adults and children) in experiments conducted by researchers at Tufts University, Boston, MA. This was not a safety study but an efficacy test to see whether the human subjects assimilated sufficient beta-carotene and converted it to vitamin A. The efficacy test was conducted without basic toxicological testing having been carried out. This was condemned as a breach of medical ethics and the Nuremberg Code (established after World War II to prevent a repeat of inhumane Nazi experiments on humans) by a group of international scientists in a letter of protest to the Tufts researchers.126

In contrast with the problematical Golden Rice, inexpensive and effective methods of combating vitamin A deficiency have long been available. The most commonly used method is Vitamin A supplements. 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.”127,128

The World Health Organization’s long-standing project to combat vitamin A deficiency uses vitamin A supplements, backed up with 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 generally available solutions. WHO says its programme has “averted an estimated 1.25 million deaths since 1998 in 40 countries.”129 According to WHO malnutrition expert Francesco Branca, these approaches are, for now, more promising approaches to combating vitamin A deficiency than Golden Rice.124

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. 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.”130

Pollan is one of several critics who 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 less like a solution to vitamin A deficiency than “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.”130

3.9.2. 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 have anti-cancer properties. The JIC announced the development of the tomato in 2008 in a press release headlined, “Purple tomatoes may keep cancer at bay”.131 Professor Cathie Martin, who led the research, published an article in the press entitled, “How my purple tomato could save your life”.132

These claims were based on the results of a preliminary 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.133 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”.134

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, for example, on pizzas and in tomato ketchup on burgers.132 It is questionable, however, whether people who are 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 pudding”135 – let alone a tomato that, at least in Europe, 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 anti-oxidant lycopene.136 Lycopene, like anthocyanin, has anti-cancer properties.

In 2011 the JIC’s GM purple tomato became entirely redundant when Brazilian researchers announced that they had developed a non-GM purple tomato with high levels of anthocyanins and vitamin C.137 In contrast with the JIC’s GM tomato, the non-GM tomatoes received little publicity.

3.9.3. “Biofortified” crops are not a sensible 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 money to buy food and, increasingly, 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 to eat 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 because it can be viewed as medicating food. Dosage is difficult to control and certain nutrients may be needed by one person, yet be excessive and potentially dangerous for the next. Also, nutritional theory is a fast-moving discipline, with today’s desirable nutrient becoming tomorrow’s undesirable contaminant.138

3.9.4. 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 Section 7).

In addition, there are ways of adding nutrients to people’s diets that do not involve the considerable expense 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.139

  • For references, please click here.
  • Download a PDF of the full GMO Myths and Truths report
  • We work hard to bring you reports backed up by strong science.
    Please help us by supporting our work.
    Donate button

Add comment

Security code