‘Robust’ evidence for GM crop benefits, says meta-analysis

By Nathan Gray contact

- Last updated on GMT

Genetically modified crops have 'significant' benefits in terms of improving crop yield, farmer profits, and reducing pesticide use, according to a new review of 147 trials.
Genetically modified crops have 'significant' benefits in terms of improving crop yield, farmer profits, and reducing pesticide use, according to a new review of 147 trials.

Related tags: Genetically modified crops, Genetic engineering, Genetically modified food

Genetically modified crops offer ‘large and significant’ benefits in both developed and developing countries, according to a new meta-analysis.

The study, published in PLoS One, concludes that despite the wide range of potential applications and potential advantages of genetic modification technologies, on average such crops are of significant agronomic and economic benefit.

The team behind the work analysed data from 147 studies on genetically modified crops, finding that impacts and benefits vary by the type of modified crop trait and geographic region.

“On average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%,”​ wrote the team, led by Matin Qaim from Georg-August-University of Goettingen in Germany.

Through their analysis, the team showed that yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops, while yield and profit gains are higher in developing countries than in developed countries.

Confusion and concern

Despite the rapid adoption of genetically modified (GM) crops by farmers in many countries, public controversies about the risks and benefits continue. While numerous independent science academies and regulatory bodies have reviewed the evidence about risks and concluded that commercialised GM crops are safe for human consumption and the environment, many remain wary of genetically modified foods and crops.

Some argue that the evidence about these environmental and agricultural impacts is mixed and that studies showing large benefits may have problems with the data and methods used, while some researchers and organisations firmly believe that genetic modifications can be a risk to human health.

This uncertainty about the impacts and benefits of GM crops is one reason for the widespread public suspicion towards this technology, said Qaim and colelagues.

“We have carried out a meta-analysis that may help to consolidate the evidence,”​ they added.

Benefit analysis 

The team carried analysed the agronomic and economic impacts of GM by collating information from 147 original studies that were built on primary data from farm surveys or field trials anywhere in the world.

“Our meta-analysis concentrates on the most important GM crops, including herbicide-tolerant (HT) soybean, maize, and cotton, as well as insect-resistant (IR) maize and cotton,”​ noted the authors. “For these crops, a sufficiently large number of original impact studies have been published to estimate meaningful average effect sizes.”

From these studies they worked out the average impacts of GM adoption on crop yield, pesticide quantity, pesticide cost, total production cost, and farmer profit.

“Furthermore, we analyse several factors that may influence outcomes, such as geographic location, modified crop trait, and type of data and methods used in the original studies,”​ they reported.

On average, Qaim and colleagues found that GM technology has increased crop yields by 21% - noting that such yield increases are generally not due to higher genetic yield potential, but to more effective pest control and therefore lower crop damage.

“At the same time, GM crops have reduced pesticide quantity by 37% and pesticide cost by 39%,”​ they said. 

However, they noted that this effect on the cost of production is not significant, since GM seeds are more expensive than non-GM seeds. 

“But the additional seed costs are compensated through savings in chemical and mechanical pest control. Average profit gains for GM-adopting farmers are 69%.”

They added that the effects on yield and farmer profit gains were found to be higher in developing countries than in developed countries.

Another twist in the GM debate?

The team suggested that affirming the evidence for the benefits of GM crops “may help to gradually increase public trust in this promising technology.”

There has been a recent backlash towards GM foods and crops in Europe and the USA. European lawmakers recently made it possible for EU member countries to ban the cultivation of genetically modified crops​ on their own soil – even if the wider EU had approved use of the crop.

Meanwhile in the USA, there has been a flurry of anti-GMO activity and several attempts to enforce the labelling of genetically modified ingredients​ on food labels.

Source: PLoS One
Published online ahead of print, doi: 10.1371/journal.pone.0111629
“A Meta-Analysis of the Impacts of Genetically Modified Crops”
Authors: Wilhelm Klümper, Matin Qaim

Related topics: Science, GM food

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I'm sure this is a Monsanto driven study

Posted by brenda,

Just like the Monsanto commercials ... Convinced this is all $$ driven and Monsanto all the way. I choose NOT to believe this garbage nor do I chose to be a Monsanto guinea pig.

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Missing the Point:

Posted by Tiger Baugh,

Like recent proposals for food labeling in various states, it almost like GMO proponents helped write some of these initiatives. They make actual implementation of GMO labeling so impratical it would be insanely stupid to make them law. It isn't nearly as compicated or difficult to enforce as politicians make it seem. This is all that it would take: (GMO plants have been banned in Europe and Japan, due to environmental and or health concerns. Do you feel conumers have a right to know if the food they eat has ingredients made from genetically modified plants? Yes or No). Producers that have No GMO will put that on the label, those that do not, don't have to reprint labels, since they are the majority. If there is any doubt that a Non-GMO claim is true, DNA testing is cheap and quick. It requires nothing else, the FDA is already at these facilities and can look at third party testing to verify food labels that claim to be Non-GMO. The consumer gets to choose, not force fed GMO foods without knowing. This approach is inexpensive, does not raise food prices or increase government payroll. Reports about the science and increase yield don't seem to report the extra herbicides and long term effect of cross pollination. They don't talk about the impact on the bee population or control of the food supply. They never address the injustice of lawsuits against farmers who lose thier property, right to grow what they want and ability to earn a living because of manipulation of the legal system. Let's have a few comments not related to science or the GMO agenda, but regarding moral issues and American liberty. If GMO foods are truly not dangerous to eat and are cheaper to grow, there are still plenty of unanswered concerns from many qualified to dispute the issues from all over the World. There remain issues of right and wrong that Americans should be aware of, and I never see those in the public forum or even grazed by articles like this one that make GMO appear a hero and disregard that thousands more tons of herbicides are being used. In Europe that is why they use the term Round Up ready in place of GM. The farmer can spray the whole field with a powerful chemical without killing the plant. The plant has a suicide gene so it cannot reproduce and neither can the farmer grow his own
seeds. He must forever buy the seeds from the same supplier under the guise of protecting the ecosystem. Haven't the courts of the land already addressed that type of business decades ago?? I also wonder who sponsored this study, terms like unbiased, when so much is ignored is suspicious.

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Nicotine and GMO's....

Posted by Cecelia Ann Jernegan,

Yep. Yep. We thought from the 1920's thru 1960's nicotine was safe too. You only have one body. Use your OWN common sense when it comes to feeding yourself and your family!

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