Genetic Modification: Food Facts Revealed
Location: Home Page > Learning Links > GM Introduction > Issues in brief > GM Food Facts Revealed
Find below: What's in it for me? ... GM crops ... GE Food ... Potential problems with GM food
Is the public protected? ... A question of Coexistence? ... Peeling away the skin
What's in it for me?
Food produced using GM has been available for some time, much of it unlabelled and unproven. Although genetic engineering uses advanced techniques, its results are very much hit and miss, since the underlying science is still in its infancy. A closer look reveals its shortcomings.
All plants and animals consist of tiny cells, each containing a long thread-like substance called DNA. A gene is a section of DNA in which are 'written' the details of one substance, called a protein. A plant cell may contain many thousand genes, and the proteins and genes interact to build and regulate the plant. When plants or animals reproduce, both parents are of the same species, and genes from both parents appear in their offspring. Often a gene is associated with a visible trait or feature.
Genetic engineers use invasive techniques, such as virus infection, to move desired genes between different species. Extra gene parts are added, such as an artificial 'promoter' and frequently another gene which confers resistance to an antibiotic. Gene fragments may also occur in the new life-form and the initial products are often unstable. The entire process differs radically from conventional breeding.
Genetically Modified (GM) crops
The sales pitch for GM crops is that they benefit the food producer. They can be engineered to withstand specific weedkillers, or produce their own insecticide, or have longer shelf-life, etc. Side effects however do occur. In North America, where many GM crops are grown, butterflies have died, and weeds have evolved to survive specific weedkillers. Most GM plants are able to reproduce - they can spread their pollen several miles and may cross-breed with closely related plants.
A series of 'Farm Scale Trials' in the UK ended in 2003. These were widely criticised for their deficiencies, locals were angry at the lack of consultation, and many crops were destroyed. Trial results showed that the use of GM beet and oilseed rape was more harmful to wildlife than non-GM. The maize trial results however were skewed due to the use of atrazine on the non-GM crop - this weedkiller was banned soon after. No GM crops have yet been grown commercially in the UK - the Government says 'coexistence' rules should be in place first.
Genetically Engineered (GE) Food
Since the nineties, genetically engineered products have quietly slipped into the UK food chain e.g. GM soya and maize imported from the Americas, animals raised on imported GM feed, and GE food additives and enzymes.
Soya is used widely, providing flour, oil and an emulsifier. Maize appears in cereals and snacks, and provides the glucose syrup in sweets and soft drinks. Meat and dairy products may come from animals which have been fed on GM plant material. Much of our animal feed comes from imported GM material, such as soya protein, oil seed rape and maize. Additives and enzymes are used extensively by the food industry. One example of a GE enzyme is chymosin - used for producing many hard cheeses. Many artificial flavourings can be produced by genetic engineering.
Potential problems with GM food
When foreign genes are inserted into DNA, their exact locations and therefore their effects will be initially unknown. Interactions between genes are highly complex, and as yet poorly understood. However, it is the behaviour of a plant's genes that determines whether that plant is safe to eat or not. So when gene changes are engineered there can be unforeseen side-effects that only appear later. Some types of GM crops are specially engineered to poison insect pests.
While some efforts are made to avoid marketing a plant which could be toxic to humans, when a soy bean with a gene from a brazil nut was tested, it was found to be potentially fatal to people with a nut allergy. An accident occurred in the States after a food supplement, produced using GE, appeared on the market in 1989. Thousands of people suffered from an outbreak of EMS disease, which killed at least 37. The food supplement, L-tryptophan, was later found to contain minute amounts of highly toxic by-products.
Antibiotic resistance genes in GM plants can be transferred to bacteria, enabling the bacteria to withstand the effects of medical antibiotics. These genes cause widespread concern, but European law has been stretched and many are still authorised. Certain gene 'promoters' are also regarded as extremely dangerous by some scientists. It is likely too that crops, engineered to resist a specific herbicide (weedkiller), will contain significant residues of that herbicide.
Is the public protected?
Possible hazards of genetic engineering are allergic reaction or poisoning, antibiotic resistance, new diseases, and disruption to ecosystems and wildlife. But the authorities, under industry pressure, are making only a token effort to control and research the new technology. Although politicians say GM crops have been thoroughly tested, few proper feeding trial reports have been published, and only narrow environmental studies. The government is advised by 'independent' committees, which review the GM industry's own tests. Many committee members have close industry ties.
Regulators use the principle of 'Substantial Equivalence' - a flawed idea, dismissed by serious scientists. This states that if a GM food is assessed to be 'substantially equivalent' to its non-GM version, then it is safe to eat and need not be fully tested. In reality each GM food is unique. Present regulations fall well short of the controls for new drugs.
Labelling of GM foods in the UK is not at all customer friendly. Present regulations permit levels up to 0.9% of 'approved' GM material in food without labelling. Products from animals fed on GM feed are still not labelled, and it is known that parts of genes from the feed can sometimes end up in the animal's body. So unless you choose food produced to 'organic' standards, which prohibit the use of GM, you may well be eating GM material unknowingly.
A question of Coexistence?
Despite the regulations, GM crops are increasingly contaminating non-GM food - see www.gmcontaminationregister.org. In the US, Starlink maize (approved only for animals) caused widespread allergy problems in 2000, and ProdiGene was prosecuted in 2002 when vaccine-producing maize escaped. In the UK recently we've seen unauthorised Bt10 maize and LLrice601 from the US being barred by the regulators - belatedly. Details of the UK Government's public consultation on coexistence (2006) are on our website (below).
Peeling away the skin
Much of the genetic engineering hype just does not relate to reality. The industry says GM foods are needed to feed the world, while at the same time claiming patent rights which threaten the small farmer. Human safety and environment are at risk in the rush for profits. Few would argue against genetics in medicine, but industry promises require a large pinch of salt.
There was an overwhelming consensus against GM food in the 'GM Nation' public debate of 2003, but the Government is biased in favour.
Find Location Site Map