Results from a long-term feeding study with mice were interpreted as showing that consumption of a genetically modified corn developed by Monsanto (NK603 x MON810) led to lower fertility and body weight.
The study has not been peer-reviewed but a report was released on 11th November by the Austrian Ministry of Health, Family and Youth, which managed the study. To read the full report, click here.
“The number of females without litters decreased with time in the GM and ISO group, especially in the fourth generation,” wrote the researchers, led by Professor Jurgen Zentek. “In the group fed with [a non GM corn cultivated in Austria] fewer females were without litters, and accordingly more pups were weaned.”
The researchers noted that a 90-day feeding study is considered “sufficient” for the detection of adverse events, but chronic effects may only become evident in longer-term mutigenerational studies.
“This is the first study investigating a stacked event in a multigeneration study focussing on mice in reproduction and development,” they added.
Biotech giant Monsanto has been quick to respond to the study, and released a statement on Friday emphasising that the study has not been peer-reviewed, as well as quoting ‘two internationally recognised experts’ who concluded that the study contained “significant flaws”.
Study details
The feeding trials lasted 20 weeks using the fertile outbred mouse strain OF1/SPF. The animals were fed a diet containing 33 per cent of NK 603 x MON 810 corn, or a closely related non-GE variety.
MON810 is the only genetically modified crop approved in the EU, although not for human consumption. It has been cultivated for animal feed since 1998 and requires a review every ten years. It is engineered to produce a naturally occurring toxin, Bacillus thuringiensis, which has insecticidal properties. It also contains genes that allow it to survive applications of Monsanto’s herbicide Roundup
The results indicated a statistically significant decrease in the sizes of the litters and the weight of the pups in the third and fourth litters in the GM-fed mice, compared to the control group.
“The trial indicates that dietary interactions with the host organism have to be further evaluated,” wrote the authors. “Regarding the sensitivity of the topic, studies are needed to extend the database using standardized feeding trials with clear endpoints such as reproductive performance and a backup by genomic, proteomic and metabolomic traits.
“Whether similar findings could be expected for other animals, needs to be evaluated in studies including reproductive traits. Future studies are necessary to determine the impact of normal and transgenic dietary ingredients on the organism,” they concluded.
‘Devastating’ oversight
In a statement by Greenpeace, the environmental campaigners said that the study is “further evidence that the food and feed safety of genetically engineered crops cannot be guaranteed.
“The biotech industry is playing a game of genetic roulette with our food and with health.
“The reproductive ramifications of this GE maize were totally unexpected - regulators around the world have previously considered this variety to be as safe as non-GE varieties: a potentially devastating error.
“That alone should be a good enough reason to close down the whole biotech industry,” said Greenpeace.
Monsanto replies
Jerry Hjelle, PhD, vice president of Monsanto’s regulatory group responded to Greenpeace’s statements, saying: “Once again, these organizations have demonstrated that their primary interest is sensational headlines and not scientific substance.
“Every time a preliminary study like this comes out, Greenpeace and the Center for Food Safety cry ‘wolf’. And time and time again, scientific scrutiny finds that GM crops and food are safe.”