According to a feeding study published in the Organic Systems Journal – pigs fed a combination of genetically modified corn and soy suffer more frequent severe stomach inflammation and enlargement of the uterus than those fed a non-GM diet. Lead Researcher Judy Carman of Flinders University in Australia says the five-month study combined real on-farm conditions with strict scientific controls. Carman says pigs were used not only because we eat them – but also because we share similar digestive systems with the animal. According to Carman – we need to investigate if people are also getting digestive problems from eating GM crops.


The study found that the average rate of severe stomach inflammation was nearly three times as high in pigs eating genetically modified crops. The rate was four times higher for male pigs eating a GM diet. The conclusion of Carman and her colleagues is that it would be prudent for GM crops destined for human food and animal feed to undergo long-term animal feeding studies preferably before commercial planting – particularly for toxicological and reproductive effects.

Monsanto is questioning why the study focused on uterine size and stomach inflammation rather than body weight and feed conversion. The company said those factors are routinely used as endpoints in health assessments and have been measured in hundreds of studies where GM crops have been fed to poultry and livestock with no negative effects.

Carman admits her findings on weight and feed efficiency largely matched those of Monsanto”s. Then they went further and dug deeper. That”s when she says they found significant evidence of harm from eating GM crops. But Monsanto representative Thomas Helscher says many of the differences in health outcomes were within normal range – adding that given the ages of the pigs, the author”s speculation about differing uterine weights might be the result of pigs in estrus. Carman says that can”t be the case – as pigs were randomized before they began their diet.

BIO Director of Animal Biotechnology David Edwards is questioning the study”s methodology. He also notes that overall stomach inflammation was more common in non-GM fed pigs. Also – while researchers say they used a combination of GM grains to mirror how most hogs are fed – Edwards says the combination muddies the specific origin of the outcome.

The study has already been used in testimony to support labeling of products with genetically modified ingredients in Massachusetts.