If any of us needed yet another reason to avoid genetically modified food and anything having to do with GMO giant Monsanto, here’s a big one.

Reuters is reporting that a new French study (PDF) has found that rats fed a lifetime diet of Monsanto’s genetically modified corn end up dying prematurely with multiple tumors and organ damage. The study took place at the University of Caen and the findings were published Wednesday in the journal Food and Chemical Toxicology.

Research consisted of feeding the rats Monsanto’s GMO seed NK603 – which was developed to be tolerant to their weed-killing herbicide Roundup – and given water to drink that was contaminated with Roundup at levels allowed by current U.S. law. 50 percent of male and 70 percent of female rats exposed to these two Monsanto products died earlier than those that were not, suffering from mammary tumors as well as severe liver and kidney damage. The research covered two years of experimentation with Roundup and the rats, following up on a short study done by the same team that voiced similar concerns about the toxicology of Monsanto’s product back in 2009.

While some “experts” have publicized their doubts about the authenticity of the findings, the French government has asked its own National Agency for Health Safety to investigate and the European Commission has asked it’s own food safety authority, the EFSA, to verify the findings of the study. As for Monsanto, the company states that they will review the study but that “peer-reviewed scientific studies performed on biotech crops to date…have continuously confirmed their safety.” Here in the U.S., California Right to Know is working hard to pass Proposition 37 this November which would require the labeling of GMO foods and this study is sure to add some fuel to that fire.

[via Reuters]

Image Credit: Image publicly released by study authors