Is human genetic engineering safe?

Safety and genetic engineering

As with any other technology, it is necessary to subject the application of genetic engineering to plants to a safety test. General and specific questions about security must be asked. Some risks apply to all transgenic plants, many risks must be assessed on a case-by-case basis.
Plant genetic engineering can look back on an excellent safety standard. Since the first releases in the early 1980s, neither ecological damage nor damage to human health has ever been observed!
The assessment of such risks is not without problems, since everyone sets different priorities and is differently tolerant of risks. For example, very high risks in leisure activities are often accepted or even sought. The following risks are conceivable in the area of ​​"green" genetic engineering:
  1. The transfer of transgenes (= genetically engineered DNA) through pollen to related plants
  2. The transfer of transgenes to microorganisms
  3. Allergies to genetically modified plants or to new components in them
  4. Unwanted toxins in genetically modified plants
These points should be briefly discussed:

to point 1:
If a plant is genetically modified, i.e. new DNA is introduced into the genome of a plant, this plant will pass on the new genes to each subsequent generation. This takes place on the one hand through the egg cell and on the other hand through the pollen. The pollen is spread either by the wind or by animals (mostly insects). So if you grow genetically modified plants in a field, the pollen can also get onto other, unmodified plants.
This is not a problem with nightshade plants (potatoes, tomatoes, tobacco) or maize, because these plants have no close relatives in Europe because they originally come from America. In other plants, such as rapeseed, a transfer of pollen to related plants is conceivable. The type of pollination (wind, insects, etc.) also plays a role here.
When assessing risk, one should also bear in mind that conventionally grown plants also pass on their pollen to wild herbs and thereby influence their genetic makeup.

to point 2:
A distinction must be made here between two processes: on the one hand, the absorption of transgenes in bacteria in the human intestine when transgenic food is consumed and, on the other hand, the transfer of transgenes, especially the antibiotic resistance genes, from plants to soil bacteria. The first case is already discussed under a different keyword (see there). The second case, the transfer of plants to soil bacteria, should be considered here in more detail:
First generation transgenic plants carry e.g. the kanamycin resistance gene, which gives the plants resistance to the antibiotic kanamycin. Critics fear transmission to soil bacteria. In fact, many soil bacteria already naturally carry such a resistance gene. The transgenic plants do not pose a particular threat, since the gene is already present in the natural environment.

to point 3:
If you bring a foreign gene into a plant and then a new protein is formed there, some people could develop an allergy to that protein or are already allergic to it. It is therefore important to label food accordingly (required by law!) So that allergy sufferers know what they are eating. Whether a protein acts as an allergen (i.e. can trigger allergies) can often be seen by how long the protein remains unchanged in the gastric juice. Harmless proteins are broken down immediately, while allergy-causing proteins are often retained for more than 15 minutes or longer. So you can ensure safety in advance. It is also possible to use antisera from allergy sufferers to test in advance whether a certain protein (e.g. from nuts) can trigger allergies. In summary, one can say that genetically modified plants can theoretically trigger allergies, but that this risk is not fundamentally greater than with conventional plants. Here is an example: Very many people are allergic to kiwifruit, for example. If the kiwi were a genetically engineered plant, it would never have been approved for human consumption (according to the "Novel Food" regulation, the safety of exotic fruits, plants, etc. that have not yet been available in the EU must be proven!).

to point 4:
It is very unlikely that transgenic plants released for human consumption contain toxic by-products. For example, before the introduction of the longer-lasting transgenic tomato ("anti-slush tomato"), extensive investigations were carried out (including animal experiments) in order to rule out any residual risk. In the past, plant breeders have produced many tens of thousands of new conventional plant varieties. Even so, there were only two of them that were unsuitable for human consumption. This shows that the emergence of toxic plant varieties is an extremely rare process.
(Note: Basically, many of our food plants naturally also contain toxins, which is why some plants are only edible when cooked. Of the many natural ingredients in various plants, some are beneficial to health and others harmful, but of course the benefits predominate.)