Source: Lindsay Eyink, via Wikimedia Commons 

In November of last year, Food and Chemical Toxicology -- a peer-reviewed scientific journal -- came out with a study that was a goldmine for opponents of GMO food. The study claimed that rats who fed on GM corn created by Monsanto (MON) treated with the company's Roundup herbicide were more likely to develop mammary tumors and die prematurely.

The study became highly contentious in the months that followed. Those who are against GMOs -- for a variety of reasons -- claimed it was the first shoe to drop in an onslaught of evidence pointing to the toll such crops would take on human health. Those in favor of GMOs -- members of the scientific community in particular -- had serious reservations about the conclusions drawn by the study.

Source: Rosalee Yogihara, via Wikimedia Commons 

In an effort to put an end to the debate, the journal officially announced a full retraction of the study's publication last week.

What went wrong
Although Food and Chemical Toxicology "unequivocally found no evidence of fraud or intentional misrepresentation of data," on the part of authors, there were two glaring errors that led to the study's retraction.

The first was the fact that the number of rats included in the study was simply too low to warrant such conclusions. The second and more alarming concern was the fact that Sprauge-Dawley rats -- the type used in the study -- have a notoriously high incidence of tumors even under normal circumstances. It could not, therefore, be definitively concluded that the sickness found in the rats fed genetically modified food was outside the range of normal variability. 

What it means for investors and consumers
Though the retraction wasn't a huge surprise, the news is nonetheless good for Monsanto, as well as fellow GMO manufacturers Dow Chemical (DOW), DuPont (DD), and Syngenta (NYSE: SYT). This represents a string of public relations wins for these companies, following the defeat of Washington's I-522 initiative, which would have mandated the labeling of all foods containing GMOs.

It's important to note what this retraction means and what it doesn't mean. To date, there are no reputable scientific organizations that have found evidence of human damage caused by GMOs. At the same time, the retraction doesn't mean the magazine supports GMOs, just that the conclusions drawn from this one study aren't supported by the facts.

As it stands, GMOs are relatively new, with the first publicly available GMO foods entering the market just 20 years ago. While human health is the most serious concern for scientists, there are also questions of environmental degradation and the concentration of worldwide cash crop seeds in the hands of a select few.

It will be years before we can say for certain whether or not genetically modified foods are a good idea, but one thing is for sure: those who produce them have been winning the PR battle lately -- for the first time in a long time.