The case for GM food

Lack of vitamin A causes the death of about 6,000 children a day, worldwide, from infectious disease. This is a tangible health hazard of vast scope that dwarfs any hypothetical hazard attributed to genetically modified (GM) foods.

Recently, an affluent Australian lawyer living in London told me his social set deliberately avoided buying GM food products because, as they are produced to meet the needs of developing countries, they are too “downmarket” for discerning people.

This incident neatly encapsulates the vastly different context of food safety and choices available in the developed world compared with the developing world. In the developed world consumers have the luxury of worrying about hypothetical fears, while in the developing world people suffer and die from very real, preventable food hazards. Satisfying the concerns of wealthy Western Europeans can interfere with the provision of better nutrition for the rural poor in countries like India, Brazil and Bangladesh.

Decisions about GM food need to be based on a comprehensive assessment of safety, actual hazards and a balance of the possible harm of using such food against the harm that can come from interfering with its availability. It becomes easier to demonstrate and communicate improved safety in spite of the possibility of some hypothetical harm when the novel food provides tangible health benefits.

Plants are not intrinsically safe to eat. They are selected by evolution not to provide perfectly nutritious and safe food for humans, but to successfully produce seeds for succeeding generations. Because of this, plants possess many specialised toxins that protect them from being eaten. Rapeseed, for instance, contains toxic erucic acid, while the castor oil plant produces ricin, one of the most deadly poisons known.

Potentially hazardous foods can be eaten because humans have discovered ways of cooking and processing the food so that the poisons are destroyed, and because the human liver produces special enzymes that neutralise many of the plant’s chemical defences.

Production of such toxins is not limited to the plants themselves. Fungi that live on plants, for example, often produce compounds that are potent poisons. In 2003 several “organic” cornmeal products had to be withdrawn from supermarket shelves in the UK because the Food Standards Agency detected fungal toxins, presumably from the use of mouldy grain. Such problems are not often found in food produced in developed countries because modern methods of insect control (including GM methods) minimise insect damage that accentuates the problem.

Traditional crop breeding methods can, and sometimes do, increase human harm from natural plant chemicals. For instance, when naturally insect-resistant strains of food crops have been selected by breeders using traditional techniques, they sometimes contain elevated amounts of dangerous natural pesticides.

Natural poisons are therefore a tangible manageable risk presented by our current food crops, and there is no reason to believe they are preferentially accentuated by modern genetic techniques. It is arguable that modern, highly regulated GM approaches allow better management of these natural food hazards than the traditional, largely unregulated, crop breeding.

Micronutrients, including iodine, iron and zinc, and the nutrients in many plants that provide vitamin A, are components of food that are essential in human nutrition. In the past, solutions to problems caused by dietary micronutrient deficiencies have been sought by supplementing the diet with external sources of the micronutrient after crops have been harvested, such as adding iodide to salt. A new strategy called biofortification aims to remedy micronutrient deficiencies in food by breeding crops that accumulate high levels of micronutrients during growth.

Biofortification methods have a great practical advantage over supplementing harvested food. The solution to a health issue is packaged genetically within the crop’s seed, distributed with the seed and then multiplies with the seed. This approach is suitable for achieving major improvements in human welfare because the efforts of plant breeders are targeted at natural nutrients that have major consequences for human health out of all proportion to their minute quantities in the food.

Biofortification strategies are being strongly supported by several humanitarian agencies promoting economic growth and welfare in developing countries. One of these agencies, Harvest Plus, is actively funding the breeding of a wide variety of new biofortified crop varieties for developing countries. The Bill and Melinda Gates Foundation has also donated $US57 million towards the creation of micronutrient-rich staple food plants.

Biofortified pro-vitamin A rice created by transgenic methods - the so-called Golden Rice I and Golden Rice II - are emblematic of the potential benefits of micronutrient-rich plants.

Some 127 million preschool children are vitamin A-deficient. Not only does this cause blindness in about 250,000-500,000 children, it is also detrimental to the immune system, promoting the deaths of about 6,000 children a day worldwide from infectious disease. Vitamin A deficiency plays a significant role in the global burden of disease from malaria, the global burden of disease from diarrhoea, and much of the global respiratory disease burden.

While welfare agencies have had significant success in supplementing the diets of poor families in developing countries with vitamin A, they have difficulty in reaching all nutritionally deprived children. For instance, in India, despite vitamin A supplementation programs, UNICEF reports that 57 per cent of children under 6-years of age still suffer subclinical vitamin A deficiency.

Rice naturally lacks vitamin A, meaning that millions of children are vitamin A deficient because they lack the resources to regularly supplement rice with other vegetables. GM rice varieties that provide pro-vitamin A in the grain, called Golden Rice, originated from the pioneering work of biologists Peter Beyer and Ingo Potrykus who transferred traits from daffodils and bacteria into rice plants that gave rice grain the ability to produce pro-vitamin A, the important vitamin A precursor and human nutritional source of vitamin A.

Great effort has gone into thoroughly testing their GM rice varieties to ensure this transgenic rice is suitable for use by farmers in developing countries. Significant contributions have been made by the plant technology company Syngenta, which has improved on the original work by Beyer and Potrykus.

In 2004 improved varieties of pro-vitamin A biofortified rice (now referred to as Syngenta Golden Rice I and containing about 6 ìg of pro-vitamin A per gram of rice grain) went through practical farm field trials in the US, supervised by Louisiana State University. Using conventional breeding methods, Golden Rice I varieties are currently being crossbred in India and the Philippines with local rice varieties. The charter of the Golden Rice Project is to ensure that pro-vitamin A enriched rice is made available to low-income farmers at no extra cost and that poor farmers would be free to sell this rice in local markets.

One of the difficulties faced by this humanitarian initiative is speculation spread by Greenpeace that exaggerates the amount of rice children would have to eat to get a benefit from Golden Rice. This exaggeration arises from ignoring progress beyond the initial development stage, the fact the recommended daily allowance (RDA) of vitamin A contains a safety margin that allows for three months reserve supply of the vitamin to be stored in the liver, and that nutritionally impoverished people need far less vitamin than the RDA to positively and dramatically affect their health. At 6 micro-g of pro-vitamin per gram of rice, typical daily rations of Golden Rice should have a significant impact on vitamin A deficiency.

Nutritional benefits of Golden Rice are easily distributed as all that is needed is contained within the seed, which can be passed on from farmer to farmer at little or no cost. No adverse health effects of pro-vitamin A-enriched rice, either actual or hypothetical, have been identified. The rice plant will be of an appropriate type for the local growth conditions and cultural preferences, and the rice requires no special fertiliser or resource that is not already used by white rice. Economic studies by economist Kym Anderson suggest that the potential welfare benefits of this rice to Asian counties would be $US15.2 billion per year.

In 2005, scientists from Syngenta announced a new GM rice, called Syngenta Golden Rice II, that produces 23 times more vitamin A-related nutrients than the first prototype. It seems likely that this new rice will deliver in one small 60g portion of rice an amount of pro-vitamin A that will meet the child’s recommended daily allowance of 300 micro-g, which takes any questioning of nutritional impact of this new technology off the agenda of the GM debate.

Given that 6,000 children a day die due to vitamin A deficiency, and that methods currently used to supplement diets are not reaching all malnourished children, unnecessary delays in getting Golden Rice into the hands of poor farmers constitutes a real hazard.

Significant delays have been created by anti-GM lobby organisations such as Greenpeace, who have consistently tried to create the impression that the Golden Rice varieties have inadequate content of vitamin A.

In countries with good standards of nutrition, the opportunities for health benefits from GM foods are different. However, there are several GM products in the research pipeline that should be very attractive to even the most choosy shoppers.

One example is new vegetable oils that contain omega 3 fatty acids, which will become available in cotton seed, soybean and canola vegetable oils in the near future. Omega 3 is the name given to certain essential fatty nutrients such as docosahexaenoic acid (DHA). There is a substantial body of scientific research that demonstrates these oils can improve health. Ocean microbes are the current important primary source of these oils, and these reach the human diet through fish and fish oils.

The next Australian GM food to reach the market place could well be a cottonseed oil with omega 3 DHA in it. The health-promoting characteristics of such an oil would be very attractive as it would promise less heart disease, less rheumatism, protection against Alzheimer’s disease, and augmented intelligence in children.

The availability of vegetable oils containing DHA could help to relieve threatened ocean fish stocks from the ecological pressure of intensive ocean fishing. In such a situation, hypothetical undefined long-term risks of the GM crop would seem less important to many consumers.

This article has attempted to illustrate the risks and benefits of GM foods with examples for which we have factual knowledge. This allows an evidence based discussion of the likely positive and negative consequences of the wider use or the food in question to be explored based on actual risks.

Most safety concerns about GM foods come from focusing on unintended damage to human health from eating the new food and avoids discussion of the unintended harm from preventing its use. New technologies can even have unanticipated beneficial consequences.

Alertness to these unexpected benefits of innovation opens up new avenues for improving human welfare. Bias against allowing actual human welfare benefits from novel technology because of excessive precaution has the opposite effect. Examples include unnecessary delays in the delivery of Golden Rice to farmers, and the recent rejection of US maize shipments of food aid during a 2002 food crisis in sub-Saharan Africa, based on arguments about the GM content in the food.

It is to avoid such situations that the health benefits of crop innovation, scientific research and biotechnology in general need to be repeatedly spelt out to the wider community.