GM-free Scotland

News | February '10 | Patches of well-placed shade

Image of a pile of booksThe purpose of our system of publishing scientific papers is to make new knowledge available to anyone who has a vested interest in the subject. This is good in theory, but does it always work in practice?

A major thrust of GM crop commercialisation has been the development of 'Bt' crops. These generate their own 'Bt' insecticide, reducing the need for spraying and the yield loss from insect damage. However, it has long been predicted that, because of the constant presence of the GM-generated toxin in the plants, insects would readily evolve the ability to survive it. This would be very bad news for the biotech industry which has staked so much on Bt crops, and is a rather sensitive subject.

One scientist who reviewed the data on emerging insect resistance to Bt noted that hundreds of papers on the topic have been published in the last five years. He also noted that different authors were using different definitions of resistance, and were monitoring resistance using incomparable methods. Some, seemingly, failed to reach the obvious conclusions that their data supported. There may be indications here that researchers have been shifting the goal-posts to make sure their studies didn't offend the biotech industry. For example, by defining resistance as occurring only if the insects involved are causing significant economic damage, it's possible to avoid noticing the problem.

The reviewer also traced reports of two undeniable and severe cases of resistance to Bt maize. One occurred in South Africa, and was published the South African Journal of Plant and Soil, a journal not available on-line. The other occurred in Puerto Rico in 2006, and lead to the withdrawal of the Bt seed by its manufacturers: the report of this important incident only appeared in a peer-reviewed journal after a Freedom of Information Act request to the American Environmental Protection Agency was made three years later.

In other words, amidst hundreds of published papers which seem to have made sure they reached biotech-friendly conclusions, the one which contained irrefutable data on insect resistance to Bt was published where few would ever notice it, and the incident most significant to US farmers was published neither willingly nor within a useful time frame.

On the thorny subject of insect resistance to Bt, the US Departments of Agriculture (USDA) seems to have been only too happy to protect the reputation of biotech crops. And when it comes to the other thrust of GM crop commercialisation, 'Roundup Ready' crops, the policy of the USDA seems to be much the same.

Roundup Ready crops are genetically transformed to survive spraying with the weed-killer, Roundup – where the active ingredient is glyphosate. When one USDA scientist arranged for the publication of eight papers on the side-effects of glyphosate on non-target plants in a leading journal of agronomy, his press release about the implications of these studies was, apparently buried by his Department. The collected papers gave real concern that the widespread use of glyphosate on Roundup Ready crops is a threat to the sustainability of agriculture. They revealed problems such as the interference with the synthesis of plant defense compounds in the roots predisposing the plant to fungal attack, disturbances in important soil microbial populations altering nutrient availability, and mineral deficiencies in the plants. Such interactions depress crop yields, not only in Roundup Ready crops, but in future generations planted in the same field. This is information the US government clearly does not want to pass on to its farmers after heavily subsidising their use of glyphosate on GM crops for years. Since farmers don't read scientific journals very often, the USDA can probably count on keeping the information to itself for some time.

Sad to say, EU regulators don't seem to have much more integrity than the US ones. When Roundup Ready soya come up for re-approval in Europe in 2007, the German Depute Commissioner for health had his assessment of the GM crop published in a food safety journal. The purpose of this was to spotlight his department's risk assessment process. In support of the safety of the crop as feed, he summarises the “results of feeding experiments on non-target vertebrates” in a table. Five studies on livestock, such as cows, chickens and pigs are listed, plus four rat studies. All these experiments were short-term, and none indicated problems.

Spot the deliberate mistakes? By 2007, when the GM soya approval ran out, four studies had been published which suggested that mice fed Roundup Ready soya showed signs of a toxic response in the cells of vital organs. The mice studies were not mentioned. It seems that rats which don't demonstrate problems after eating GM are vertebrates, while mice who have problems with their GM chow are spineless. Curiously, 'non-target' vertebrates for Roundup Ready feeding studies included several types of livestock which are routinely fed soya. Acceptable published studies seem to have had a spotlight shone on them, while the unacceptable data were left in the shade.

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