Genetic modification (GM) of food and other produce is probably the most contentious subject in agriculture today. Protagonists say it will feed the world, reduce the use of insecticides and fertilizers, and more. But opponents, especially in Europe, are extremely critical of it.
Genetic modification basically involves inserting a gene from one species into another in order to confer certain properties. For instance, a gene sequence derived from the bacteria Bacillus thuringiensis (commonly known as Bt) confers insect-resistance to the plant into which it is inserted. Bt itself is also used as an insecticide. Soybeans are genetically modified to be resistant to the systemic herbicides glyphosphate or glufosinate, so the herbicide can be sprayed on errant weeds without harming the main crop. Glufosinate-resistant rice is now available, while GM rice with high salt-tolerance or insect resistance is under development. Maize is available as insect-resistant (bt-maize), herbicide-resistant or vitamin-enriched. Other gene sequences confer drought resistance on crops or increased yields. The new generation of GM crops that are currently under development include increased levels of omega-3 fatty acids in soybeans and an absence of allergy-causing substances.
The first genetically modified seed was produced by Monsanto in 1996. Now, up to 85% of the maize crop in the US is genetically modified, as well as up to 91% of soybeans and 88% of cotton. India grows substantial amounts of GM insect-resistant cotton, while Brazil and Argentina grow GM soybeans. Globally, genetically modified crops now account for 6-7% of cultivated agricultural land.
Of European countries, Spain is the country where most GM crops are grown. Austria is totally against it, on the grounds of environmental damage and harm to human and animal health, while Ireland has recently imposed a ban on the cultivation of GM crops. GM labelling rules exist in Europe (but not Iceland) so that consumers know if they are consuming GM produce or not. However, a plant or product is still allowed to be termed ĹGM-freeĺ if it contains up to 0.9% of a GM variety.
Critics of GM food say that the use of insecticides and herbicides has actually increased rather than decreased, food production has not actually increased and farmers are not better off, as they have to buy seeds and fertilizer. In the US, weeds have become infected with the genetically modified gene sequences used on neighbouring fields, which has resulted in weeds becoming resistance to the pesticide used on the pesticide-resistant GM crops.
In Denmark, the costs incurred by separating conventional from GM maize, together with the costs of seed, outweigh the financial benefits to farmers of growing GM maize.
Some critics are concerned about health effects of GM products. It has been shown to produce an increase in allergies and may affect the liver, pancreas, kidney and reproductive systems, although more research is needed on this subject. Although animal studies are not always reliable, the American Academy of Environmental Medicine says: ôSeveral animal studies indicate serious health risks associated with GM food consumption including infertility, immune dysregulation, accelerated aging, dysregulation of genes associated with cholesterol synthesis, insulin regulation, cell signaling, protein formation, and changes in the liver, kidney, spleen and gastrointestinal system.ö
Americans are becoming concerned about the use of genetically engineered bovine growth hormone, known as rBGH, which is designed to prolong milk production after a cow gives birth. It is said that the hormone increases the likelihood of infection in the udder, leading to greater antibiotic use in the animals which in turn increases the likelihood of antibiotic resistance in humans. A coalition called Health Care Without Harm is campaigning on this topic.
There is also growing concern about IGF-1, a growth factor produced in greater amounts in milk when cows are treated with rBGH. In a position statement on rBGH, Health Care Without Harm says: ôIt remains unclear whether drinking rBGH milk will contribute to an increase in human blood levels of IGF-1 significantly more than drinking non-rBGH milk or other dietary factors. If it does there would be concern since elevated IGF-1 in humans is associated with increased rates of colon, breast, and prostate cancer.ö
Genetic modification is also used in the drug industry and for manipulating enzymes. One enzyme (chymosin, found naturally in rennet) is sometimes genetically modified from bacteria or fungi for use in vegetarian cheeses as a cheese coagulant.
In Iceland, a company called ORF has been developing pharmaceutical growth factors from transgenic barley for use in cancer and stem cell research. These are greenhouse-grown, but two proteins have been grown experimentally outdoors in Gunnarsholt, South Iceland. One was for ORF's own use, while the other was for industrial purposes. However, this summer activists broke into the compound where the barley was growing and destroyed the crop.
Barley is grown as a food crop in Iceland, and there had been fears that the transgenic barley would reproduce with the cultivated barley. In the US, the pharmaceutical GM industry uses plants like tobacco to avoid the risk of contamination of seed used for food or animal fodder.
GM soybeans, maize, sugar beet and potatoes are also fed to animals.
For more information on the disadvantages of GM food, check out GM Watch.