What's the problem with genetically modified foods

Risks and Side Effects

© Brian Brown / istockphoto.com

The last 30 years have shown us that agro-genetic engineering causes massive problems of an ecological, social and economic nature.

Contamination, resistance, loss of biodiversity, market concentration, patents, pesticides and much more: the list of negative consequences of the use of genetic engineering in agriculture is long.

Loss of genetic diversity

About 10,000 years ago, people began to systematically grow plants. Many different varieties were created, which are adapted to the respective climatic and geographical conditions, or which are resistant to certain pests and diseases. The result is a large genetic pool of useful plants with many different properties.

This diversity is the basis of any future breeding. Transgenic plants and animals endanger the already severely threatened diversity of species and varieties. Because by concentrating on a few genetic engineering varieties, the gene pool of agricultural crops is shrinking ever faster and local varieties that are optimally adapted to their respective location are being displaced. The commercialization of genetically modified crops is very expensive. That is why the genetic engineering companies focus mainly on only a few species that promise them high profits. So far these have been maize, soy, cotton and rapeseed.

Uncontrolled spread

Contamination occurs through pollen, insects, bees and birds, through declaration errors, mixed up seeds, contaminated machines, during transport and not least through "food aid" from the USA to the Third World. The outcrossing of genetically modified plants into wild relatives is particularly critical. Outcrossing also gives rise to so-called super weeds. These are wild herbs that farmers do not like, are resistant to several pesticides and sometimes even have to be pulled up again by hand.

Outcrossing is a sad reality in Canada: genetically modified oilseed rape crossed into the wild rape, which has established itself in nature and spreads the property of herbicide resistance. But the cultivated plant itself can also become a problem. In Canada, GMO-free rapeseed can no longer be grown on a single hectare because all the seeds are genetically contaminated. In the USA, too, large parts of the seeds of maize, rapeseed and soy are contaminated by genetically modified seeds. And now even seed banks are contaminated with transgenic material. Once released into nature, genetically modified plants and their modified genes cannot be retrieved.

Economic consequences

For years, genetic engineering companies such as Monsanto (now owned by Bayer), Syngenta (now Chemchina), BASF and Co. have been assuring that GMO-free agriculture and the cultivation of transgenic crops can coexist without any problems. However, dozens of cases show that the contamination of the environment, seeds, feed and food by genetically modified plants has long been a global reality.

The genetic contamination brings the conventional and organic agriculture into existential difficulties. Organic and conventional cultivation are sometimes even impossible. In order to avoid contamination, farmers have to pay considerable additional costs for tests, controls and preliminary examinations. This increases the prices for their food. In this way, agro-genetic engineering is displacing all other forms of land management.


Another problem is the development of resistance: so-called Bt plants encourage the development of resistant pests. Bt is the abbreviation for the bacterium Bacillus thuringiensis. This soil bacterium produces a protein that is toxic to insects and soil organisms. Genetic engineers have transferred the associated bacterial genetic material to plants. The genetically modified plants permanently secrete poison. Constantly exposed to the poison that is formed in each cell in the genetically modified plants, the harmful insects become resistant to the toxin after a few generations. The cotton boll drill is now resistant to the poison of genetic engineering cotton.

Bt plants also pose a considerable risk to the environment, because the poison is not only effective against pests, but also against beneficial insects. Studies have found negative effects on various butterfly species - such as the monarch butterfly - as well as other beneficial insects - such as the decline in beneficial predatory insects in US Bt maize fields. An ecological disaster that is exacerbated by the fact that after the main pest has been decimated by Bt plants, other harmful insects (so-called secondary pests) appear more frequently. In China and India this phenomenon led to dramatic crop losses.

And the cultivation of herbicide-tolerant plants is also increasingly proving to be a disaster. The associated large-scale use of pesticides significantly decimates the diversity of plants and insects. In addition, after a few years the required amount of pesticides in such genetically modified plants increases sharply because more and more weeds are becoming resistant to total herbicides such as glyphosate. This should be compensated for with increasing amounts of pesticides.

Health risks

The genetic engineering companies and industry-related researchers claim that transgenic plants are harmless to health and have been rigorously tested. But worldwide there are hardly any reliable studies on the effects of genetically modified plants on humans and animals. Long-term studies are completely lacking. The rule are short studies lasting 21 to 90 days, in which the feed conversion, but not the toxicity of the genetically modified plants, is examined. There is no data to prove that GMOs are harmless to health.

The all-clear cannot be given, on the contrary: the incorporation of the artificial genes can trigger changes in the desired gene as well as in undesired locations in the genome of the plant. In addition, the inserted genes can themselves harbor health risks.

There is also the risk that antibiotic resistance genes will render antibiotics ineffective even more quickly. Because there is a possibility that antibiotic resistance can pass over to bacteria in the human intestine, via what is known as horizontal gene transfer. The antibiotic resistance genes are used as so-called marker genes. With their help it is determined in the laboratory whether the genetic manipulation carried out on the plant was successful or not.


Transgenic plants are generally patented. This turns the common basis of life, which no one can invent or technically produce, into private “intellectual” property.

For thousands of years, farmers have been sowing part of their harvest or exchanging seeds with others. Billions of people worldwide live mainly from agriculture and are dependent on this basic right. Patents on plants make this farming tradition a criminal act. They force the farmers to buy their seeds every year. Because the farmers are only allowed to use genetically modified plants as licensees. As it is customary to keep part of the harvest and to sow it again the next year, they are forbidden. In North America in particular, Monsanto uses patent law to deprive farmers of elementary rights with the help of gag agreements.

Read more about patents on life here.