Longest-Running GMO Safety Study Finds Tumors in Rats

Are GMOs dangerous? A new study shows that Monsanto’s genetically modified corn and Roundup herbicide cause negative health effects in rats, and is raising questions about the safety of GMOs.

  • Monsanto’s Roundup-Ready corn caused a host of negative health effects in rats, including tumors and premature death.
    Photo Courtesy AFP Photo/Criigen
  • Monsanto’s Roundup-Ready corn.
    Photo Courtesy Monsanto

More than two decades ago, the U.S. Food and Drug Administration (FDA) granted GMOs “generally regarded as safe” status, meaning the industry had no obligation to conduct long-term safety studies. And while GMOs don’t have what scientists call “acute” effects, what about “chronic” effects — those that come on gradually and can’t easily be tied to one cause? The French study — the most comprehensive GMO safety assessment ever conducted — highlights that concern. It involved 200 rats and spanned two years, the life expectancy of the species of rat used. Previously, the longest study had lasted 240 days, says Michael Hansen, senior scientist at Consumers Union and an expert on GMO research. Industry-funded studies typically last just 90 days.

The researchers investigated how eating Monsanto’s Roundup-Ready corn (and any Roundup herbicide traces that may come with it) affected rats’ health. They separated rats into 10 groups: Three had part of their standard diet replaced at varying levels with Roundup-Ready corn that had been treated with Roundup in the field; three received the same feed protocol, but with untreated Roundup-Ready corn; three ate no GM corn but had tiny amounts of Roundup herbicide in their drinking water; and one control group ate two-thirds standard rat chow and one-third non-GM corn. Each group contained 10 females and 10 males.

The researchers say their results show “severe adverse health effects, including mammary tumors and kidney and liver damage, leading to premature death” from Roundup-Ready corn and Roundup herbicide, whether they were consumed separately or together. Almost all of the ill effects manifested after 90 days. By the end of the study, 50 to 80 percent of the females had developed large tumors, compared with 30 percent developing tumors in the control group. In males, liver congestion and necrosis were 2.5 to 5.5 times higher than in the control group, and there were 1.3 to 2.3 times more instances of kidney disease. Overall, among the rats receiving GM corn and/or Roundup, up to 50 percent of males and 70 percent of females died prematurely, compared with only 30 percent and 20 percent in the control group.

So does the study close the case? Are GMOs dangerous? Predictably, industry-aligned scientists are questioning the study, but even longtime critics of GMOs, including Hansen, have concerns. Hansen says that while the new study was longer and better designed than any of the industry GMO safety studies, the sample size — 10 males and 10 females per group — was too small to draw conclusions from.

Hansen says, however, that while the individual comparisons may not be statistically significant because of sample size, the results still paint a troubling picture. The study made 54 comparisons between treated rats and control rats, and in all but four, the treated rats showed worse outcomes. “That’s suggestive that there’s something going on and that there should be further research,” Hansen says, adding that a possible reason the researchers didn’t use a greater number of rats to get more robust results is because multiyear rat studies are extremely expensive.

That fact highlights how little funding goes to GMO safety studies. Between 1992 and 2002 — a period of rapid GM crop development — the USDA spent about $1.8 billion on biotech research, of which only 1 percent went to safety testing. Meanwhile, the ag industry uses its patent power to maintain tight control over who researches what, and it dominates the research agenda at U.S. agriculture universities. The French study didn’t fully illuminate the situation, but it’s a start.

8/3/2014 1:49:35 PM

Hi SoulM, If you copy and paste a website to notepad, then copy and paste that to the Internet, you'll probably get a cleaner copy. ----------- It seems very statistically significant that you would have an increase from 30% to (50 to 80)%. That's an increase of 66% to 166%. How can that be statistically insignificant? It seems that studies like this are a clear indication that there is something significantly wrong with GMO technology for food production. ----- From what I've read inserting new genes by (e.g. shooting GENE covered gold flecks into DNA) causes a lot of effects that would make the food worse, such as; - Inserting into the middle of other genes destroying or altering their functionality - having the gene on all the time (by using a protein that keeps the gene turned on continuously) in all the cells so that the poison or protein is always being produced throughout the plant (This I assume would lead to lower nutrition since the plant is spending a lot of it's resources producing a toxin continuously) - the activator may be turning on inactive genes that produce toxins or by producing more of a protein than normal produces unwanted protein production (e.g. 30,000 genes in the human body produce 80,000 different proteins -> a protein has more than one function) - Altering the function of other genes due to the fact that genes interact in a complicated way with each other and not singly as Genetic Modification assumes - using marker genes, that are cheaper, but promote anti-biotic resistance - the addition of extra DNA that my produce toxins - proteins that are possibly allergenic being added to foods that are normally not allergenic ----- The theories to explain why GMO's are bad for you make sense. The theories to explain why GMO' are good for you just say there's no definitive proof it's bad for you. That's not good science

7/22/2014 6:58:39 PM

google genetic literacy project, or Kevin Folta, a U. of Florida prof. and then start reading. You will soon finds that TMEN has harmed their credibility by printing this nonsense. There is no credible proof that there is any danger from consuming gmo food. Try checking with those who receive gmo insulin to see if they are dying from it or are grateful. What about all that gmo cheese out there? better do some checking you paranoid ones who have fallen for the wacko propaganda. Tmen needs to realize that more are realizing the truth that G.E. is safe technology when it comes to food. They also need to realize that their long term business model will have to quit catering to those who will never get home from woodastock.

6/5/2014 12:31:31 PM

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