RETRACTED: When science rights a wrong

A widely criticised 2012 paper claiming that genetically modified (GM) corn causes cancer has been retracted.

A scientist's worst nightmare

Genetically modified organisms (GMOs) are organisms that have had their DNA changed in the laboratory, usually by adding some DNA from a different organism. The idea is to give the organism a special ability such as protection from insects, faster growth or healthier food, or to create some kind of half human, half animal monstrosity.

The retracted paper was published in the September 2012 edition of the journal Food and Chemical Toxicology and was written by a French professor named Gilles-Éric Séralini and his colleagues.

Dr Séralini studied NK103 corn (also called maize), which has been modified to protect it from a common herbicide (or weed killer) called glyphosate. Farmers growing this corn can spray their fields with glyphosate and all of the weeds will be killed, but the corn will survive.

Many scientists have studied the health effects of GM foods and there has never been any good evidence that they cause any more health problems than regular, non-GM food. There was a lot of interest, therefore, when Séralini and his co-authors said that the NK103 maize caused cancer and other bad health effects in rats.

But there were a number of odd things about the study:

Odd thing 1: Big scientific discoveries, especially those that overturn what we think we know, tend to be published in big, popular journals such as Science or Nature. This study was published in journal that most people have never heard of.

Odd thing 2: Séralini let some journalists read his paper before it was published, but made them sign a contract - called a non-disclosure agreement - that said they were not allowed to ask any other scientists about the study. This is not the proper way to do scientific reporting and many journalists and scientists got cranky.

Odd thing 3: When he announced the paper, Séralini also announced that he was releasing a book and movie about the toxic effects of GM food. Most scientists don't do this.

GM Golden Rice, rich in beta carotene

When GM goes horribly wrong

There was a lot of criticism of this study by other scientist, with many concluding that the results were most likely due to pure chance rather than any effect of the GM corn. Respected scientists described the study as "scientifically unworthy", with "major flaws", "bogus" and "shoddy science".

The company that owns the journal, Elsevier, probably felt a bit silly for publishing it and so they investigated the study in more detail. They decided that the study had no scientific merit, and a few week ago the journal asked the authors to withdraw the article but they refused, and so now the journal has retracted the article. This means that the article is no longer considered to be science. It is kind of like the journal saying: "OK guys. Look, we made a mistake, now let's all agree to never speak of this again."

Genetically modified links:

• Scientific papers get retracted all the time, and for many different reasons. The great website Retraction Watch keeps you up-to-date with all of the latest retraction news.
• One famous retractions was a paper in the prestigious journal The Lancet that said there was a link between vaccinations and autism (there isn't).
• And then there is the anaesthesiologist who wrote 21 papers and was a highly respected scientist until it was discovered that he'd made up all of his research. All of this 21 papers have been retracted and he is no longer a highly respected scientist.
• Everything you ever wanted to know about genetically modified organisms and more from Nature.com.