Genetically Modified Foods

Last update: April 2012 
Contact: Thorsten Galert

Authors

I. Technical and scientific aspects

Genetically modified (GM) foods (see module Genetically modified foods) are staple or luxury foods which consist wholly or partly of genetically modified organisms or products made from them, or where a genetically modified organism or product is made use of in the production process. The genetically modified organism may be a micro-organism, a plant or an animal. 

Human beings have always tried to modify plants and animals through breeding, especially in relation to food production. Unlike conventional breeding methods (selection, cross-breeding, hybrid and mutation breeding), however, this new green genetic engineering (see module Green genetic engineering) allows us to transfer in a more targeted manner not only whole genomes, but also individual genes which may even come from entirely unrelated organisms with very different evolutionary histories. The aims here are the same as with conventional methods of breeding; to increase and guarantee yields, and to improve processing and quality performance on a larger scale and with greater efficiency.

Genetic engineering and transgenic organisms

In the strict real sense of the term, genetic engineering (see module Genetic engineering) covers all the methods and in-vitro-processes involved in isolating, modifying, multiplying and transferring DNA, the genetic blueprint. Genetic engineering enables us to isolate specific sections of DNA from cells, modify them and transfer them to other cells. Genetic material may be transferred to totipotent cells, that is, those which are capable of forming multi-cellular organisms like plant cells or early embryonic mammalian cells. The transfer may also take place to cells which are at a later stage involved in forming totipotent cells, such as germline cells or cells whose nuclei are used in nuclear cell transfer cloning techniques (as with "Dolly" the first cloned sheep). Either way, these totipotent cells develop into genetically modified or transgenic organisms which, apart from characteristics of their own species, also produce those which are encoded in the foreign genetic material injected into their genome.

Genetic engineering in food production

In food production genetic engineering is at present used mainly in plants and microorganisms:(see module Genetically modified micro-organisms) such classes of organisms are particularly suitable due to their asexual reproduction and easy cultivation. Genetic engineering in vertebrates (see module Vertebrates), including all the animals human beings have domesticated, is much more difficult. However, the employment of nuclear cell transfer cloning techniques could change this in the near future.

In the context of food production, genetic engineering is used for various different purposes which can be defined more closely by employing the distinction between "input traits" and "output traits":

Modifying input traits

The term "input traits" refers to those characteristics of a plant which are relevant for its cultivation. Genetic engineering is used to modify input traits in order to increase the efficiency of the agricultural or biotechnological production of certain human and animal foodstuffs or additives, or to enable their production in a given quality or quantity in the first place. This is mostly done by influencing tolerance and resistance traits. A number of crops such as transgenic corn (e.g. Bt corn or MON 863 (see module GM corn MON 863) and MON 810 (see module GM corn MON 810)) and GM potatoes have been injected with bacterial genes to make them resistant to certain pests, while other plants such as soy beans and rape (see module Genetic soy beans A2704-12 and genetic rape) were supplemented with genes to make them tolerant of certain herbicides. The aim is to reduce the amount of pesticides and herbicides used in the cultivation of these plants. In the biotechnological production of chymosine, a component of rennet from the stomachs of calves used in making cheese, the gene concerned was transferred from cattle to bacteria, thus enabling the enzyme to be produced in large quantities.

Modifying output traits

Output traits, unlike input traits, describe characteristics pertaining to the usage of a plant. Genetic engineering can be used to make individual natural products more processable, improve their content or make them more digestible to humans. One example of this is "golden rice", which contains more iron and provitamin A than conventional strains of rice. Another example is the potato grade Amflora (see module Potato grade Amflora) whose starch production has been improved.

Another area of application for genetic engineering in food production is in genetic testing procedures, which can be used in conventional breeding methods for diagnostic purposes and for monitoring and quality control in food.

With regard to genetic modifications one has to distinguish whether or not "alien" genes are introduced. In cases where genes which are foreign to a species are introduced, the outcomes are called "transgenic" plants, animals etc. If, on the contrary, only species-specific genes are applied for the modification, the result is a "cisgenic" organism. The production of cisgenic plants is enabled by what is known as smart breeding (see module Smart breeding). Although laboratory techniques are being used here as well, the procedure rather resembles classical breeding methods due to the restriction to species-specific genes.

There are a number of ways in which food can be made from genetically modified organisms or can contain them:

• The food itself is a genetically modified organism (GMO) or a part of one, like the so-called Flavr Savr tomatoes (see module Flavr-Savr tomatoes).
• The food contains microorganisms which have been genetically modified. Dairy products such as yoghurt or cheese, beverages like beer or wine, and also baked goods or sausages may contain such microorganisms as so-called starter cultures (see module Starter cultures). 
• The food is produced from genetically modified organisms, parts of which are detectable in the end product. Some examples of this are cornflakes from genetically modified corn, ready meals with transgenic soya, and ketchup from genetically modified tomatoes ("Flavr Savr" or Zeneca tomatoes).
• The food is made with additives (see module Additives) such as sweeteners and flavour enhancers, aromas and secondary ingredients obtained with the aid of genetically modified organisms (usually bacteria and yeasts), but which are not contained in the additive itself. So far, there are only a few testing procedures which can detect residues of GMOs in individual additives.
• The food is produced through smart breeding. An example of this is the work of researchers from the International Rice Research Institute (IRRI) (see module International Rice Research institute). They were able to add a genetic sequence, which is naturally existent as a variation in only a few rice breeds, to other rice breeds. As a consequence, the new rice breeds are better equipped to adapt to the oxygen-deficient conditions under water and are thus more insensitive to floods. They can stand in the water for a longer period of time without dying, which is usually the case during prolonged floods.

The discussion surrounding the use of GMO occasionally includes concerns regarding cloned farm animals (see module Cloned farm animals) and their use. In this respect it should be pointed out that the genetic material of reproductively cloned organisms has not undergone any modification or in-vitro manipulation. In other words, such clones need not be designated as being GMO, and therefore are not to be included in the larger field of discussion.

Cultivated areas of genetically modified foods

According to the International Service for the Acquisition of Agri-biotech Applications (ISAAA) (see module ISAAA) genetically modified crops (GM crops) were being cultivated over 160 million hectares worldwide in 2011. Compared to the previous year, the total surface area of land cultivated with GM crops increased by 8%. 29 countries worldwide are growing GM crops, 10 of them are industrial countries, whereas 19 are developing or emerging countries. The largest cultivated areas for GM crops are in the USA (69 million hectares), Brazil (30.3 million hectares), Argentina (23.7 million hectares), India (10.6 million hectares), Canada (10.4 million hectares), China (3.9 million hectares), Paraguay (2.8 million hectares) and South Africa (2.8 million hectares).

The only GM crop which is currently approved for commercial cultivation in the European Union is the genetic potato Amflora (see module Potato grade Amflora). This genetic potato produced by the company BASF has been authorized in spring 2010, which led to heavy protests by several Member States. In January 2012, the chemical company finally announced its plan to move its plant biotechnology activities from Germany to the USA. This move was justified with the ongoing skepticism regarding GM crops in large parts of Europe in view of which it appeared preferable to concentrate on the growing markets in North and South America and in Asia.

For ten years, the cultivation of the genetically modified maize variety MON 810 (see module GM corn MON 810) by the company Monsanto had been authorized in Germany. On April 14th, 2009, however, the permission of MON 810 has been withdrawn. The German Federal Minister of Agriculture, Ilse Aigner, justified this decision (see module  Prohibition of cultivation of MON 810 in Germany) with reference to new studies according to which MON 810 posed a threat to the environment. In 2007, MON 810 was grown on an area of approximately 2,700 hectares. This equals circa 0.15 percent of Germany's overall are of corn cultivation. The cultivation of MON 810-corn has been authorized in the EU since 1998. The initial authorization expired in April 2007. Even though a readmission of this genetically modified corn breed has taken place, numerous EU-countries, such as France, Greece, Hungary, Luxembourg and Austria have called on so-called national hedge clauses and have prohibited the cultivation of MON 810 in their countries.

Next: II. Legal aspects