22 years ago, the first genetically modified plants sprouted in the world's fields. Since then, the ecological, health and economic effects of plants have been intensively studied in many thousands of studies. Health risks have not yet been confirmed. Nevertheless, these still dominate the public debate.

Although genetically modified crops (GM crops) are by far the best-studied crops in the world, is its cultivation often perceived as risky and unpredictable consequences. Especially in Austria. A 2010 Eurobarometer study shows that Austrians are much more pessimistic about biotechnology and genetic changes than the residents of all other EU countries.

The new breeding methods are also rejected in those areas in which health and ecological benefits have now been well proven - interestingly, particularly by those groups that have committed themselves to healthy food and sustainable production. But resistance to new breeding methods seems to be easing. Not least because of the overwhelming number of studies and the development of new precision processes, which meanwhile make many of the previous criticisms pointless.

What is genetic engineering?
Two characteristics of products of the previous "classic" genetic engineering have become the most popular in agriculture: resistance to insects and weed killers. The fact that these changes are welcome to many farmers is testified by the growing arable land on which GM crops are grown. But do farmers really benefit from this? And what are the consequences of growing GM crops for the environment and food safety?

A large number of studies are required to understand a large subject area. There are more than 6,000 studies on genetically modified corn alone. In order to be able to classify the effects of the plants, it makes little sense to consider individuals of these studies - an overview of the entire study situation is required. Such reviews exist, they are called reviews and meta-analyzes. They are by far the most meaningful of all scientific work. All information in this article is based on such reviews, wherever there are any.

There is great skepticism about genetic engineering, especially in Austria. However, harmful effects have not yet been confirmed and resistance is easing.

Less pests, more weeds
A comprehensive meta-analysis from 2014 summarizes the consequences of switching from conventional seeds to genetically modified ones. On average, farmers harvest 22 percent more crops when they switch from conventional seeds to GM varieties. The reason for this is the lower pest-related crop losses, which are made possible by insect-resistant plants.

In developing countries, these yield increases are significantly higher than in industrialized countries, where farmers have more pest control options. The amount of pesticides used is reduced by 37 percent by switching to GM varieties. Here, however, a distinction must be made between insecticides (insect control) and herbicides (weed control). While the use of insecticides by pest-resistant varieties has dropped sharply, the use of herbicides by the cultivation of herbicide-resistant plants has increased in many regions.

Radioactive plants in the health food store. Science Buster Martin Moder explains in the video why there is no clear border between "genetic engineering" and "natural".

Less insecticide poisoning
Taken together, however, the number of pesticides applied decreases by about 37 percent due to the switch to GM plants. This reduces the pesticide costs for farmers by 39 percent. The lower costs of sprays together with the higher yields mean that farmers' profits from switching to GM crops are 68 percent higher. This increase in income is also more pronounced in developing countries than in industrialized countries. The meta-analysis, which was financed by the German Federal Ministry for Economic Cooperation and the EU , finds no difference in these developments between studies financed by industry and non-industry-financed studies.

The cultivation of insect-resistant plants brings yet another decisive advantage for farmers in developing regions. By growing insect-resistant cotton in India alone, millions of cases of insecticide poisoning among cotton farmers are avoided each year; a fact that is rarely mentioned in discussions about the health effects of genetically modified plants.

Field workers in Bangladesh apply spray agents to the fields without any protective clothing
Smallholder farmers in Bangladesh spray insecticides on mollusk plants without any protective equipment.

Environmental impact
It is difficult to make a general statement about “the ecological effects of GM plants”. Every genetically modified variety is different and must, therefore, be assessed separately. Nevertheless, there are reviews that draw a general conclusion about the ecological effects of genetically modified plants.

More gentle tillage
Herbicide-resistant plants allow farmers to control weeds effectively without plowing the fields intensively. Mechanical tillage using a plow sounds harmless, but damages the organisms living in the soil promotes soil erosion and humus degradation, prevents the formation of a naturally grown soil structure and leads to high greenhouse gas emissions. These negative effects can be reduced by using herbicide-resistant plants, which enable so-called conservation tillage.

Reduced insecticide use
Since fields on which insect-resistant plants grow do not have to be sprayed against the pest in question over a large area, other field organisms are less affected by the insecticides. The resistances introduced are so-called Bt proteins that come from bacteria and are harmless to humans. There are hundreds of different Bt proteins that protect against different predators.

Long before there was genetic engineering, Bt proteins were used to control insects and are still a common spray in organic agriculture. The use of Bt plants not only reduces the need for insecticides in your own field but also in the surrounding ones. A large review has shown that in regions where Bt maize is grown, the use of insecticides also decreases in fields that are planted with conventional maize. This is because the use of Bt plants reduces the pest density in the entire region.

Reduced land requirements
The higher yields of genetically modified plants mean that less space is required for a certain amount of food. One speaks of increased land-use efficiency. Overall, this means less land reclamation, which often goes hand in hand with the destruction of ecosystems.

The ecological effects of genetically modified plants are often overestimated. Numerous research projects have shown that the different effects on ecosystem and biodiversity between different conventional maize varieties are greater than that between genetically modified Bt maize and its unchanged starting variety. Overall, however the changed varieties do better.

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Genetic engineering-Melanzani in Bangladesh - excerpt from the TV reportage “Brave new genetic engineering - a revolution in agriculture” 03

Impact on consumers
Perhaps you have already come across these images: rats that have been eaten by gigantic tumors - allegedly due to long-term feeding with genetically modified maize and herbicide residues in drinking water. The spectacular results come from a study published in 2012 by the French molecular biologist and critic of genetic engineering, Gilles-Éric Séralini. The images went around the world, and the headlines of many news magazines announced that evidence of the negative health effects of genetic engineering had been provided.

On the other hand, it was hard to be read anywhere when the study was withdrawn a year later due to serious methodological shortcomings. Nor was it heard that the claimed results contradicted numerous other studies and that an EU-funded repetition of the rat study according to international standards could find no signs of health impairment.

What remained in public perception were the pictures of the tumor-eaten rats, combined with headlines such as "Higher cancer risk from genetically modified maize" (ZDF Today), which were disseminated prematurely and unquestioned. Not least because of this, the belief that genetically modified food is unhealthy has become a matter of course for many people.

Less poison
This is not only contradicted by the results of countless laboratory tests, but also by the directly measurable effects. While farm animals were completely GM-free until 1996, they nowadays mainly consume the genetically modified feed. Comparing the health data of over 100 billion farm animals before and after 1996, it turns out that the switch to genetically modified feed had no health consequences. Even among the hundreds of millions of people who have been consuming GM food for two decades, there are no indications of health consequences. Among the many thousands of studies that have been carried out in the 22 years of commercial cultivation, there is no serious evidence that genetically modified plants would be more harmful to health than conventional plants.

On the contrary. One of the most extensive meta-analyses to date has shown that Bt maize has a significantly lower fungal poisoning burden than conventional ones. These poisons are sometimes suspected of being carcinogenic and promoting embryonic malformations. The reason for the lower pollution of genetically modified maize is that the fungal attack occurs primarily in places that have been damaged by predators. However, since Bt maize is protected from insect attack, it cannot be easily colonized by fungi. Apart from the reduced fungal toxin concentration, the nutrient content remained unchanged.

What are the problems?
Many of the problems that have rightly been criticized for a long time now have been solved. Until recently, researchers had no control over where an inserted DNA sequence inserted in the genetic information of the plant. In addition, for technical reasons, it was necessary to include antibiotic resistance in addition to the desired gene. Thanks to the development of new methods, such as the gene scissors CRISPR / Cas9 01 , this is no longer necessary. The new precision genetic engineering of recent years has made it possible to make minimal changes in genetic information that cannot be distinguished from the spontaneous mutations that occur permanently in plants. Still, there are problems that remain.

Spread
It cannot be ruled out that genetically modified plants will become more competitive than their unchanged starting forms and could also assert themselves outside of the arable land. However, this cannot be generalized. Many cultivars, such as corn and potatoes, cannot survive outside in the field in the wild. It is different from rapeseed. In areas of the USA where herbicide-resistant rapeseed is grown, it has also been found off the fields. However, such concerns are included in the approval process and the cultivation of GM oilseed rape is not permitted in Europe.

Resistance
Since evolution does not stop at fields, insects can develop resistance to Bt plants. By 2016, 16 cases of resistant insect populations had been discovered that greatly reduced the benefits of Bt plants within the affected region. However, the development of resistance of predators is not a genetic-specific problem, but a general problem of pest control.

There are now several strategies available that have been shown to delay insect resistance. The same applies to the emergence of weeds that have developed resistance to the herbicide glyphosate (brand name Roundup), which is often used in GM plants. This is also a serious problem, but not a new one. Weed resistance does not affect genetic engineering in particular, but chemical weed control in general.

monopolization
A common criticism is that GM crops promote a monopoly on seeds. The majority of the patents for genetically modified plants are in the hands of a few large seed producers. One reason for this is that small breeder cannot afford the costly long approval process. The methods of the new precision genetic engineering could remedy this.

The European Court of Justice is currently negotiating whether plants that have been modified with new technologies should be considered genetically modified if no foreign DNA has been introduced. Should it be decided that the new precision technologies are not covered by the old genetic engineering regulation, methods such as CRISPR / Cas9 would also be used for small breeders, which would counteract the formation of monopolies?

The potential is lost in fears
In 2016, 110 Nobel Prize winners, more than half of those still alive, signed an open letter to Greenpeace. In it, they urged the environmental protection organization to accept the scientific consensus on genetically modified plants and to refrain from their action against modern plant breeding. They point out that there is not a single known case in which a human or animal would have suffered health damage from the consumption of genetically modified food and that it has been shown on several occasions that GM plants are generally more environmentally friendly than conventional varieties and a blessing for the global biodiversity.

Golden rice
The letter also contained a very specific request: to refrain from campaigning against golden rice. This is a rice variety that, thanks to genetic engineering, contains large amounts of beta-carotene, the precursor to the vital vitamin A. UNICEF estimates that one to two million children in developing countries die each year from avoidable vitamin A deficiency. Almost all of these are in poor regions where farmers only have home-grown rice as food, but which does not contain beta-carotene.

For this purpose, the golden rice was made with the help of non-profit funds. The aim is to distribute the vitamin-enriched seeds in the affected regions and thus give farmers the opportunity to independently meet their vitamin A requirements. There would be no license payments and farmers could reapply the harvested seeds every year.

Environmental protection organizations are opposing this. In the Philippines, test fields were attacked and devastated by opponents of genetic engineering. Greenpeace describes the golden rice as a "dangerous illusion". One of the main arguments is that rice is a Trojan horse that is supposed to increase the acceptance of green genetic engineering. Added to this is the classic argument of the unforeseeable consequences. Which potential horror scenario should compete with millions of dead children per year remains unmentioned.

What is missing: a reason-based discussion
Apart from research, the discussion about genetically modified food has so far largely been on an ideological-emotional basis. But after more than 20 years of green genetic engineering and the absence of practically all predicted horror scenarios, a rethinking seems to have started. Resistance also seems to be crumbling among the Greens. The Greens politician Theresia Bauer, Minister for Science, Research and Art in Baden-Württemberg, wrote a few weeks ago in a guest post for Spiegel online: "The Greens should recognize the state of the art. And give genetic engineering a chance. "

Agriculture can never be operated without ecological effects. It is sensible to choose the methods that turn out to be the most sensible after an intensive examination. Organic farming performs best in some areas. In others, genetically modified plants triumph.

The past two decades have shown that, contrary to high expectations, genetic engineering has not been able to solve all agricultural problems. However, they have also clearly shown that a fundamental rejection of modern breeding methods does not serve the interests of the environment, consumers or farmers. The emergence of the new genetic engineering precision methods should be used to restart the discussion and to continue on a reason-based level.