On 19 September 2012, Gilles-Eric Séralini and his colleagues published a sensational study that, in their opinion, brought to the fore clear indications that genetically modified crops and Roundup are dangerous to health. Media across the world picked up on this report and published disturbing photos of rats with enormous tumors. As we say today, the story "went viral." Let's look to the cause now, with a few months distance and maybe with a new perspective.

The study led by French toxicologist Gilles-Eric Séralini „Long term toxicity of Roundup herbicide and a Roundup-tolerant genetically modified maize" was published online by the scientific journal Food and Chemical Toxicology. In two years long experiment rats were fed maize NK603 (GM corn developed by biotech company Monsanto to resist the herbicide Roundup) or combination of the maize and Roundup. Séralini reported that these rats developed higher levels of cancers, had larger cancerous tumors and died earlier than rats fed normal corn.

Sharp criticism of the study soon followed. Various scientists pointed to the significant shortcomings in the research and raised several questions. The main criticized points were:
1. Breed of rats used
For experiments 'Sprague-Dawley rats' were used. This is a laboratory strain that is known for its propensity to the spontaneous development of tumors. The number of tumors that the rats develop spontaneously depends on time and amount of food that they are given. These rats are commonly used for food experiments, but only in 90-days studies, where a propensity to develop spontaneous tumors plays a minor role.
2. The number of control animals
In their experiment, Séralini et al. used 20 control animals compared to 180 treated animals. On the basis of simple probability calculations, it can be concluded that the chances of finding spontaneous tumors in the group of treated animals is much greater than the chances of finding spontaneous tumors in the control group. In addition to this, they used an unorthodox statistical method ('two class discriminant analysis') that aims at finding differences instead of investigating differences between the treated animals and the control group.
3. Analysis of the death rate and tumors
In manuscript there is no statistical analysis of the number of deaths. Based on the figures, there are virtually no reliable differences in the death rates to be found among the males. Séralini did not release the data underpinning the study although petition was launched requesting Séralini to do that.
Séralini et al. make an unusual distinction between small and large tumors and between external palpable tumors and internal tumors. The size of a tumor, however, is not related to how serious it is. Also in this point small control groups can cause significant inaccuracies in statistical analysis.

These objections uncover some shortcuts in the way the experiment was led and which could have affected the results Séralini presents. We should wait with conclusion whether GMO food is or is not carcinogenic till other studies proof it in more credible way.

Let's focus now on the way the study was published. The basic code of the journalistic profession is to ask for a second opinion – so how is possible that the objections of other scientists were not mentioned in the articles? In a move regarded as unusual by the media, the French research group refused to provide copies of the journal paper to reporters in advance of its publication, unless they signed non-disclosure agreements. The NDAs would have prevented the journalists from approaching third-party researchers for comment. This is how Séralini ensured that the first bulletins about their work were exclusively sensationalist reports about large tumors in rats as a consequence of eating GM maize and/or drinking Roundup.

The motive of this action is easy to uncover. Séralini fights against GM food for a long time. It can be illustrated for example by cause in 2009, when Greenpeace gained from Monsato original data from tests of effect of GM corn on rats´ health. Séralini used the data for calculation the effects by different statistical methods. As the result he claimed that the GM corn is poisonous. Soon was discovered that Séralini made a mistake and used an inappropriate statistical method, which is intended for different situations.

Séralini's conviction (true or not) led him to selectively interpret results of experiment to support his hypothesis. It is humanly nevertheless it is contrary to scientific ethical standards. Scientist should try to refute all other possibilities before publish such a serious allegation. But making a research and publication of a scientific article is not probably the main Séralini's intention. During the press conference, Séralini announced the upcoming publication of a book and the release of a film. All the signs point to a purposive, broader campaign aimed at putting genetically modified organisms in a bad light.

Many environmentalists are against GM food from different reasons, so results of the study are water to their mills. That is also why the sensational articles were spread so quickly for example through facebook. Séralini's campaign can be called as very successful because negative headline stories laden with color pictures of rats with grotesque tumors are not easily forgotten even if the studies are proved as unconvincing.

What can be conclusion for us from this cause?
We should try to discover background of the articles in media and search for different opinions, so we will not be manipulated to go blindly in one direction. We should be very also careful to spread only truthful information, because through social media we can easily affect thinking of many people.

Do you feel lost in the world of media? Would you like to know how to use social media more effectively, how to use critical thinking in daily life or how to make a successful campaign?
You can find many answers in new YEE publication "Environmentalist's guide to the media galaxy" which you can download free here