Saturday, 19 December 2009

Help us understand the new study that shows GMOs are toxic

Tom Philpott and Tom Laskawy are reporting on a new study by French researchers, which re-analyzes some Monsanto data and concludes that GMO varieties may be toxic in rats.

Philpott explains the history.
The researchers analyzed data from tests done on rats by Monsanto and another biotech firm, Covance Laboratories, submitted to European government in 2000 and 2001. The firms conducted the tests to prove that their products were safe to eat; scrutinizing the same data, the researchers arrived at a different conclusion.

The three products in question are still quite relevant: one strain of Roundup Ready corn, engineered to withstand Monsanto’s flagship herbicide; and two strands of Bt corn, engineered to contain the insect-killing gene from the BT bacteria. Roundup Ready and Bt products are ubiquitous in the U.S. seed supply, often “stacked” into the same seed.
Laskawy says the earlier Monsanto study fudged the analysis.
Firstly, let's be clear -- industry scientists got bad results, fudged the analysis and then figured no one would notice. Well, it took almost a decade, but these enterprising French scientists did notice.
To see if this is true, I read the new study. The abstract is clear enough, and it does indeed say the GMO varieties were toxic to rats:
Our analysis clearly reveals for the 3 GMOs new side effects linked with GM maize consumption, which were sex- and often dose-dependent. Effects were mostly associated with the kidney and liver, the dietary detoxifying organs, although different between the 3 GMOs. Other effects were also noticed in the heart, adrenal glands, spleen and haematopoietic system. We conclude that these data highlight signs of hepatorenal toxicity, possibly due to the new pesticides specific to each GM corn.
But, I wanted to read the actual empirical results that back this claim. There are dozens of results reported in the study, and I could not understand many of them.

Here is my request for help: Can you point to some particular table entries that support the claim in the abstract?

If you have a particular result to suggest, we can read it closely together, with one dose of open-mindedness and one dose of skepticism. Then, we can decide whether Laskawy is right that the Monsanto researchers have committed a scientific crime.

You might look for such a result in Table 1 and Table 2, which report selected parameters showing the difference between GMO-fed rats and conventional-fed rats. From the abstract, the important parameters might relate to liver or kidney outcomes. All I need is for somebody to pick and explain one or two of those parameters. Personally, I couldn't understand these tables because they seemed to lack clear information about the mean values for the GMO-fed and conventional-fed rats, the column headings were confusing to me, and the accompanying discussion did not include clear interpretation sentences.

Alternatively, you might look for such a result in Tables F or G of the appendix. Here, too, my understanding is confused, because I could not tell if these are raw results, or statistically-adjusted results based on Tables 1 and 2.

Philpott and Laskawy and the French researchers make a striking claim about the dangers of GMO crops. I'd like to understand the empirical evidence that supports this claim.

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