The GM debate is, however, a complex one, fuelled by economic, environmental and social factors.
The companies that manufacture and own the patents on GM seed say they're just a further step in the process of modification that humans have been making to plants and animals over the centuries – a bit like cheese- or wine-making, or the selective breeding and hybridisation that produced the wheat and maize we know today.
But genetic modification is different from other kinds of biotechnology as it involves the transfer of genetic material between species that are possibly unrelated in nature. It mixes together genes from species that wouldn't naturally reproduce, for example from a bacterium to a plant.
The GM seed industry argues that this new technology benefits the environment because it reduces the amount of weed killer and pesticides needed, produces more nutritious food, and helps developing countries to grow enough food to support their populations.
On the other hand, GM critics say that these crops could contaminate conventional crops, harm wildlife, and create strains of herbicide-resistant weeds; that technology alone will not solve problems of poverty and local food insecurity; and that patents on GM seed give too much power to a handful of multinational companies.
So how can you, the consumer, make sense of these conflicting messages? The following facts, supplied by Biowatch South Africa, might put a few things into perspective:
1. Increasing scientific understanding of how genes work indicates that they operate in far more complicated ways than first thought. Ongoing research shows that a gene from one organism doesn't fit neatly and predictably into the genetic make-up of another, unrelated organism. This calls into question the basis of GM as a completely safe and predictable technology.
2. None of the GM crops currently on the market are more nutritious than conventional ones.
3. In South Africa there are three GM crops on the market – GM maize, GM soy and GM cotton. All of these contain a gene extracted from a soil microbe which makes the plants themselves toxic to pests (the plant is itself a pesticide) or able to survive weed-killer spray that kills other plants.
4. No independent studies have been conducted which show that GM crops are not a long-term risk to the well-being of humans, animals and the environment, and there are differences in thinking within the scientific community about whether their potential benefits outweigh potential risks.
5. Consumers in many countries with which South Africa trades prefer not to eat GM food.
6. Many countries require GM food to be labelled. Developing countries with compulsory GM food labelling include China, Brazil, Indonesia, South Korea, Taiwan, Thailand and Saudi Arabia. Developed countries with mandatory labelling regulations include those in the European Union, Australia, New Zealand, Japan, Switzerland and Russia.
7. South Africa, along with the US and Canada, doesn't have compulsory GM food labelling regulations.
8. Large food retailers in South Africa are taking note of growing consumer concern about GM food. For example, Pick n Pay has said it would not stock GM potatoes if these are approved for release onto the market. Woolworths labels products which may contain GM ingredients, such as flour.
9. South Africa’s organic food sector is growing. From an estimated R5 million before 2003, sales of organic food grown in South Africa (domestic sales and exports combined) jumped to R155m in 2005, according to Organics South Africa. Organic food is available in some large supermarkets which cater for the mass market. Organic food in South Africa doesn't contain genetic modification.
[Information for this article was supplied by Biowatch South Africa. The article was reviewed by Prof Chris Viljoen from the GMO Testing Facility at the University of the Free State, updated October 2008.]