Saturday, August 18, 2007

A largely "Untranslated" quickie on Genetically Modified Foods

Doing research for redrafting a paper/thesis chapter, I came across at least one recent study where genetically modified foods were fed to animals and then statistically tested to see how the animals reacted vs. a variety of other diets. They in fact used Monsanto's own data, released apparently 2 years ago under lawsuit in Europe (did anyone hear about this? I faintly recall something like that, you'd think it might've resurfaced in the news at some point).

So, the re-analysis found several abnormalities in GM-fed rats, especially in weight (lower in GM-fed rat males, higher in GM-fed rat females), and initial signs of damage to detoxifying organs (kidneys, liver). I read it quickly, it didn't seem that they used a statistical test to screen out the fact that when you do hundreds of stats on something, so number will be significant by chance -- I think there is a repeated measure test one can do. Any road, this is not my forté (stats) and I'll be returned to read this and similar studies more deeply, but this is the type of study we HAVEN'T much conducted on GM foods, on the "If it quacks like a duck" theory. ("If this GM duck quacks like a duck, then we can treat it like a duck, and assume it's safe to eat.") Of course, as I commented in an earlier post, I personally don't think our chemical understanding of proteins et al. is good enough to actually determine such "substantial equivalence," and it would seem reasonable to require animal testing as we do for drugs, what hey? (Drugs, pesticides, cosmetics -- but not food?) Clearly, I think this study needs to be followed up on, in exactly the way people aren't these days: animal studies and similar epidemiology, not dissolving GM food in a tube and analyzing its chemical content, when it's not even clear we'd understand pertinent differences if we found them (i.e. the extreme difficulties in determining protein three dimensional structure, which is at least as important as any other chemical characteristic in determining its effects, if not more so.)

Abstract of the paper for those without academic library access (reprinted here under a fair use assumption):
Archives of Environmental Contamination and Toxicology
© Springer Science+Business Media, LLC 2007
New Analysis of a Rat Feeding Study with a Genetically Modified Maize Reveals Signs of Hepatorenal Toxicity

Gilles-Eric Séralini1, 2 Contact Information, Dominique Cellier1, 3 and Joël Spiroux de Vendomois1
(1) Committee for Independent Information and Research on Genetic Engineering CRIIGEN, Paris, France
(2) Laboratory of Biochemistry, Institute of Biology, University of Caen, Caen, France
(3) Laboratory LITIS, University of Rouen, Mont-Saint-Aignan, France

Contact Information Gilles-Eric Séralini

Received: 18 July 2006 Accepted: 20 November 2006 Published online: 13 March 2007
Abstract Health risk assessment of genetically modified organisms (GMOs) cultivated for food or feed is under debate throughout the world, and very little data have been published on mid- or long-term toxicological studies with mammals. One of these studies performed under the responsibility of Monsanto Company with a transgenic corn MON863 has been subjected to questions from regulatory reviewers in Europe, where it was finally approved in 2005. This necessitated a new assessment of kidney pathological findings, and the results remained controversial. An Appeal Court action in Germany (Münster) allowed public access in June 2005 to all the crude data from this 90-day rat-feeding study. We independently re-analyzed these data. Appropriate statistics were added, such as a multivariate analysis of the growth curves, and for biochemical parameters comparisons between GMO-treated rats and the controls fed with an equivalent normal diet, and separately with six reference diets with different compositions. We observed that after the consumption of MON863, rats showed slight but dose-related significant variations in growth for both sexes, resulting in 3.3% decrease in weight for males and 3.7% increase for females. Chemistry measurements reveal signs of hepatorenal toxicity, marked also by differential sensitivities in males and females. Triglycerides increased by 24–40% in females (either at week 14, dose 11% or at week 5, dose 33%, respectively); urine phosphorus and sodium excretions diminished in males by 31–35% (week 14, dose 33%) for the most important results significantly linked to the treatment in comparison to seven diets tested. Longer experiments are essential in order to indicate the real nature and extent of the possible pathology; with the present data it cannot be concluded that GM corn MON863 is a safe product.

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