Saturday, November 22, 2008

Genetically Modified Corn Found To Lower Fertility and Metabolism

The news was reported ahead-of-publication on November 11, at a scientific seminar in Vienna, Austria.

The news isn't good news for Monsanto, who sells tons of the GM corn seed. It's not good news for laboratory mice, whose litters and offspring became smaller (in number and size, respectively) than mice fed non-GM corn. And it's potentially not good news for most Americans who regularly eat GM corn and its derivatives, via livestock fattened on it, tortillas and grits, or the corn syrups that sweeten everything from soda pop and breakfast cereal, to ketchup, relish, mayonnaise, pickles, and the bun that houses the whole corn-infused lot.

It's easy to eat GM corn (and GM soy) in America, since:1
  • 81-86 percent of all corn planted in the US is genetically engineered.
  • 88-90 percent of all soybean planted in the US is genetically engineered.
Some argue that most corn in this country has been affected by genetic engineering since GM strains have cross-pollinated with wild, non-GM strains.

The Study (pdf)

Biological Effects Of Transgenic Maize NK603xMON810 Fed In Long Term Reproduction Studies In Mice

Until now, negative effects from ingestion of GM crops haven't made news:
"So far no negative effects of GM corn varieties have been reported in peer-reviewed publications."
Approval has been based primarily on short-term studies:
"Toxicological risks of GM plants are currently assessed by 90 day feeding studies with rodents. A 90 day study is considered as sufficient to detect adverse effects. However, chronic effects might only become evident in longer lasting multi-generation studies."
So, the University of Veterinary Medicine in Vienna conducted one of the first long-term studies.

They fed mice either:
  • A diet containing non-GM corn
  • A diet containing 33% GM corn (Monsanto)
All corn, both GM and non-GM, were of the same genetic lines, "grown under identical conditions in Canada." The mice were fed through 4 generations, which took about 20 weeks.


Fertility was negatively affected in mice fed GM corn:
"The number of pups weaned, the average litter size and weight at weaning tended to be lower in the GM group as compared to the [non-GM] group."

"Pup losses were higher in the GM group."
Kidney, spleen, and liver were negatively affected in mice fed GM corn:
"Significantly lower relative kidney weights were found in GM [male and female offspring]."

"Relative spleen weights were significantly higher in the GM males of the F2 generation."

"The electron histological investigation of the cell nuclei revealed differences as to fibrillar centres (FC), dense fibrillar components (DFC) and the pore density in hepatocytes [liver cells]. This could point to an effect of the GM crop on metabolic parameters."
Metabolic pathways were negatively affected in mice fed GM corn:
"The lower nuclear pore density and the lower quantity of the nucleolar components FC and DFC in both females and males, found in hepatocytes of GM mice, indicate a lower liver metabolic rate in animals fed the GM feed".

"Analyses of metabolic pathways indicated that the groups differed regarding some important pathways, including interleukin signalling pathway, cholesterol biosynthesis and protein metabolism."
  • The non-profit Center for Food Safety called the results of this study "a cause for great concern," and called for "a moratorium on genetically engineered foods pending thorough safety studies."
  • Dr. Jurgen Zentek, the study's lead scientist, said further studies to corroborate his results were "urgently needed."
  • Barry Estabrook of Gourmet Food Politics, called the results "chilling."
    "It was particularly chilling late last week to read the results of an experiment that was both long term and not conducted under the auspices of a big chemical company."
  • Greenpeace is recommending "a recall of all GMO food and crops from the market, worldwide."
  • Jeffrey Smith at the Huffington Post, says this isn't the only study to cast doubt on GM crop safety. He predicts follow-up research won't be conducted:
    "Whenever these studies or reports surfaced, scientists should have charged in to conduct intense follow-up research. Instead, the funding--to find and expose the cause of the problem--often mysteriously dries up; scientists are transferred, threatened or fired, and the health risk link to GMOs is vehemently denied."
    (Case in point: GMO Russian researcher Irina Ermakova, after presenting similar findings, had samples stolen from her lab, documents burnt on her desk, "and her boss, under pressure from his boss, ordered her to cease all future research on GMOs.")
  • Monsanto is saying the study is flawed, and that "there was no evidence of any adverse effects of the GM crop."
There isn't enough evidence here to perform a recall of, what, just about all the corn in the US? Even if there was, the sheer quantity would make it prohibitive. I don't think groups like the Center for Food Safety and Greenpeace do themselves a service by recommending such an extreme action.

However, there should at least be a move made to preserve a sizable non-GM corn crop in the US in the event these or other negative findings continue to bear scrutiny.

Update: Another new study is reporting not-so-good effects on mice fed GM corn. See: Mice Fed Genetically Modified Corn Suffer Immune Disturbances.
1 Source: USDA: Adoption of Genetically Engineered Crops in the US

No comments: