Experts not involved in the study were skeptical, with one accusing the French scientists of going on a "statistical fishing trip" and others describing its methods as well below standard. The animals on the genetically modified (GM) diet suffered mammary tumors, as well as severe liver and kidney damage, according to the peer-reviewed study which was published in the journal Food and Chemical Toxicology and presented at a news conference in London. The researchers said 50 percent of male and 70 percent of female rats died prematurely, compared with only 30 percent and 20 percent in the control group.