Introduction of untested gene sequences
We are told that GM is just a speedy way of breeding plants, it is the same as traditional cross-breeding. It is not true. While in traditional cross breading two species of the same or very similar plants are cross-breed via pollination, GM technology means the introduction of DNA from foreign, sometimes totally different organisms, such as viruses, bacteria or animals. We are also told that this is a precise technology, a gene with the required and known characteristics is transferred in a reproducible way. This is not true either. Transfer of even a single gene requires at least 3 or 4 other genes, as parts of a 'construct'. If only one gene was transferred, that gene would not be expressed to produce the gene product, the protein. There is a need for a switch which turns on the desired gene and a transcription terminator gene, which shows how far the new gene should be read and translated into a gene product. In addition there is a need for a selection marker or markers, depending on the technique used which makes possible to differentiate between transformed and non- transformed plant/cells.

The switch is usually from viruses and these are called viral promoters. CaMV 35S, the promoter from cauliflower mosaic virus is the most often used switch in today's transgenic plants. It is well known, that gene transfer between very different species does not occur in Nature. Viruses are practically the only life forms which can insert their own genetic material (DNA or RNA) into the cell of another organism forcing the host to produce viral proteins and genetic material. This is why viruses are so successful and also so dangerous to the host. Viruses have a definite host specificity but this is not absolute. The way viruses invade the host cell can be described in a simplified model. The virus is made of the genetic material to be transferred which also carries the information to produce the machinery to invade the host cell and force it to replicate the viral genetic material and the so-called coat protein. This is the packaging material for the viral information and covers it just like a coat. The coat is also responsible for host specificity. This is text book stuff and accepted by everyone. We are told that the presence of viral genetic material from cauliflower mosaic virus is not a problem for humans. We are eating it in mg quantities in our lifetime and no one has become sick. This is again true. However, when we eat the virus, the genetic material is covered with the viral-coat protein. This is specific for broccoli, cauliflower, etc (they have virus receptors), so it truly does not bind to human cells since they have no receptors for this virus. However, the viral genetic material in transgenic plants is not covered by a protein coat, it is naked DNA. This is why it is used by the biotechnologists. And since it has no coat, it has no host specificity. In other words, it is able to infect any cell type, should it be human, animal or even bacteria.

Viruses can change host specificity
Viruses are divided into groups depending on what strategy they use for infecting the host. Viruses belonging to the same group are very similar genetically, although they may have different host specificity. For instance, Hepatitis B, HIV and cauliflower mosaic virus belong to the same group. This means that the mechanism they use to invade the cells and to transfer their genetic material is very similar. So much so, that the genetic information for the virus promoter in Cauliflower mosaic virus, HIV and hepatitis B is 70-90% identical. It is described in the literature that if only a part of the genetic material of a virus invades the cell it cannot infect it. However, if the host cell already contains DNA/RNA from a similar virus, this can complement the genetic material of the incomplete virus and from there on the virus will be able to infect the host cell. Unfortunately it has never been tested or even considered what would happen to HIV or hepatitis B positive people if they eat transgenic food. Viruses can change their host specificity (their protein coat will bind to receptors of new, different species). Latest example was the Hong Kong flu which originated in birds but was then converted to a form capable of infecting humans. To eliminate the source of this infection all the chicken in Hong Kong had to be killed. Similarly, it is thought that the Spanish flu spread from infected pigs to humans. The risk of this happening with GM plans is great and not to be dismissed.

Spread of antibiotic resistance
To differentiate the transformed cells/plants from the non-transformed ones requires a selection marker, which is most often a gene coding for antibiotic resistance. It means that if a cell has this gene, it can degrade antibiotics and is able to grow even in the presence of this antibiotic. Normally, bacteria are killed with antibiotics. However, as the use of antibiotics in animal feed and human medicine is more widespread, more and more bacteria acquired resistance to one or more antibiotics. This problem is already big enough without the introduction and widespread use of transgenic plants. This is the reason why the European Union is phasing out all antibiotics from animal feed and doctors are less willing to prescribe antibiotics for common cold or other similar illnesses. However, by consuming transgenic food and feed, the problem of resistance may became more uncontrollable. Most present day transgenic plants contain a gene for antibiotic resistance in their genome. If these plants are eaten there is a chance that this gene can be passed from the food or feed to the bacteria resident in the mouth or the intestine. It has already been shown in two laboratories that the degradation of the antibiotic resistance gene is not instantaneous but takes a few minutes. This gives enough time for the antibiotic resistant gene to be transferred to bacteria. If a bacterium managed to incorporate the resistance gene into its genome this can be easily passed on to practically all other bacteria. As a result, resistance to antibiotics will spread in the bacterial population, making it difficult to treat many major diseases. It is a known fact that bacteria which developed resistance to a family of antibiotics are more capable to develop resistance to all. Multiple antibiotic resistance is a threat to the human race. Resistant bacteria spreading tuberculosis, ghonorrhea and other diseases are on the increase, especially in less developed countries. We might be soon in the same position as we were before the second World War and before penicillin was discovered.

Precision of gene insertion
Gene insertion occurs in a totally haphazard manner and at present it cannot be predicted where in the genome the gene construct is landed. It can insert itself in one or in several copies, disrupting or changing the regulation of other genes, with completely unpredictable consequences. There is evidence to prove that when transgenic plants are created using the same method and at the same time they still can be different. When plants are transformed, several hundred GM plants are created before the 'selection' process can start. By this, GM plants are selected which have has a normal appearance, develop flowers, seeds, etc. Thus GM plants are selected which grow to the same height, have the same growth characteristics and the same reproductive potential as the non-transgenic parent line.

Risk of allergy
The problem of food allergy in not new. Several of us are allergic to some foods or food component. The most common allergies are to sea-food, nuts, cereals, beans, peas, eggs, milk products or even fruits. If you know which food you are allergic to you can avoid these. If a person with severe allergy is exposed to the food he/she is allergic to, without medication this can lead to anaphylactic shock or death. With the introduction of transgenic technology one can be exposed to allergens without being aware of it. One can eat frost resistant fruit with a fish gene, or soya with a nut gene with deadly consequences. Proteins are responsible for the allergenic potential of plants. According to the biotech industry and their advisors the suggested method for testing for allergy is to carry out a database search and whether the inserted protein sequence has any homology to known allergens or not. If there are 8 or more amino acids identified in the transgene-coded protein sequencewhich are present also in any know allergen, the gene is not suitable for transfer. If no such homology is found in the databases it is suggested that it is safe to use that sequence. However, immunoglobulins are developed against a steric epitope; this means that amino acids are coming together as the result of protein folding. Since the folding is also dependent on the state and level of glycosylation, it is very difficult to predict whether a protein is allergenic or not. It is known that the more developed and differentiated a cell is, the more complex its glycosylation pattern. As a result it is impossible to predict if an antigenic sequence will be formed in a different host cell or not. The method used presently for allerginicity testing is to mix the serum from individuals with proven allergies with the extract of the new transgenic plant. If there is a reaction between the two, the transgenic plant cannot be marketed. If however a new allergen is created during the transformation process, there can be no antibody against it in the serum of the human population therefore this new allergenicity will not be detected.

Formation of new plant metabolites
During the development of agriculture through the ages edible and useful plants were selected for cultivation and for further breeding. As part of this process antinutrients and toxic plant metabolites were selected against, their amounts were therefore reduced in the new cultivars. Since these also protected the plants from insects and other predators, the new cultivars became more and more susceptible to pests attacks. Modern biotechnology is now trying to reverse this process by putting back some of these antinutrients by genetic engineering. However, inserting a foreign DNA into the genome of crop plants stresses the plant. When plants are stressed by temperature change, drought, increased amount of salt in the soil, or by any other means the plants develop protective secondary metabolites to counteract these effects. These can be compounds which are always synthesised in the plant but onli in small amounts, or can be something new, with unknown characteristics. If these compounds have never before been consumed by humans, the consequences for our gut and immune system are totally unpredictable.

Cells have limited repair capacity
Every cell has got a built-in mechanism for the degradation or repair of incomplete or faulty DNA, RNA or protein molecules. The repair mechanism however has a finite capacity and the presence of surplus unrepaired DNA, RNA or protein will change the metabolism of the cell. Development of cancer is the most obvious consequence of such a change. A transgene or its products are recognised by the cell as foreign or defective molecules, particularly if they are produced in large quantities under the influence of a strong promoter. At the same time the degradation of the cell's own defective DNA, RNA and protein molecules will not be complete and therefore the chances of the occurrence of metabolic mistakes are higher. In other words, if the transgene is expressed under a strong promoter in a host cell, it is very likely that the concentration of either the defective transgene molecules or the cell's own defective molecules will increase and this may lead to harmful metabolic changes.

Does DNA degrade in the digestive system?
We are told that all DNA from transgenic plants, even if they are from viruses or bacteria cannot harm us since DNA is fully degraded in our gut. This is true to a large extent as we know it from traditional digestive physiology. We however have known it for some time that some proteins can survive fully or partially the passage trough the digestive tract. Similarly, there is now evidence that not all the DNA is fully degraded either. Professor Doerfler's experiments showed that some DNA was not fully degraded, but was taken up through the gut wall into the circulation and passed through the blood brain barrier and the placenta. This was obvious because when pregnant mice was fed labelled DNA it was detected in the brain cells of the pups, although it was not inserted into the germ cells.

Changing the nutritional value of plants
During evolution humans selected plants which were suitable for consumption without harm. The nutritional value of our crop plants were improved by selecting against known antinutrients, such as protease inhibitors, trypsin inhibitors, alfa-amylase inhibitors, inhibitors of other digestive enzymes, toxic lectins, saponins, tannins etc. by traditional breeding. However plants then became more susceptible to pest attacks. Since pests can be controlled by the same compounds (such as, the cowpea trypsin inhibitor, Bowman-Birk trypsin inhibitor, BT toxins, etc), modern biotechnology is putting them back by genetic engineering. As a result, the nutritional value of these crops is reduced both for the pests and the human/animal consumers. Thus, an increased volume of production is needed to compensate for the lower nutritional value of these GM crops.

Testing for the effects of transgenic plants on health
There are very few independent studies to test the health effects of transgenic plants on humans. Unfortunately, the consumers are therefore unwilling subjects to a badly designed experiment where there are no controls. No one knows if she/he is eating transgenic food or not. Some people hope that they can avoid eating GM food but there is no guarantee, as it is obvious from the taco shell scare in the USA, where a GM corn, not approved for human consumption' got into taco shells. Another example of unavoidable mix-ups was what occurred this year in Europe when Canadian non-transgenic rape seeds were contaminated with transgenic ones. At the moment the view of the biotech industry is that the absence of evidence against GM means that it is safe. However this argument is not valid. The case of GM might be similar to the effects of smoking. If you smoke one cigarette you would not drop dead. However, it is now well established that cigarette smoking is harmful, leading to the development of major diseases from lung cancer to circulatory diseases, heart problems and even abortion. In fact, the health hazards of smoking were known by the tobacco industry much earlier than they cared to admit it to the public. Similarly, it might take decades for the biotechnology industry to realise the potential dangers of GM food. What are we going to do then?

Who is against GM is against Science?
Scientists who are questioning the claims and statements of the biotech industry are marginalised, silenced and cannot get a grant or a job. However, the sceptics are in fact for more science and not less. Indeed, there are several problems, which need to be solved before GM technology would be accepted by the public.