In this series I am going briefly through the "599" studies held on the GENERA database, published at Bifortified.org, in the order in which they were listed on 18 Sept 2013. The general purpose is to counter the extraordinary claims that the entries on this list demonstrate the human food safety of GM crops. See the Introduction to this series for background.
My Great Big List of Studies: Entry 2 – Aeschbacher et al 2005
The study was referenced as:
- "Aeschbacher, K; Messikommer, R; Meile, L; Wenk, C, 2005, Bt176 corn in poultry nutrition: Physiological characteristics and fate of recombinant plant DNA in chickens. British Poultry Science, 84:385-394" Full text available for free
The study concerned Syngenta's insecticidal GM corn crop "Bt-176" and was funded by Syngenta.
There were two components to the study. One was to investigate the equivalence and feed value of Bt-176 compared to a non-GM counterpart in laying hens and broiler chickens. The second was to investigate the fate of feed-derived DNA in the chickens.
In respect of the first component the authors reported the Bt-176 feed to be equivalent to it's non-GM counterpart in the short term productive outcomes required of chickens. Many industry-funded studies have reported these findings in respect of their crops, and although they are worth exploring I'll leave it to other studies with that sole focus. The second component of this study is far more interesting.
When the Bt-176 GM corn line was being assessed for food approval in Australia the regulator FSANZ (then known as "ANZFA") noted that [Medical Practitioner] Kate Clinch-Jones' submission
- "Cites a number of scientific articles as evidence that ingested viral DNA survives digestion and can be incorporated into the cells of hosts, including their foetuses and that transgenic DNA can transfer into soil bacteria and fungi. She also refers to unpublished work showing that transgenic DNA from pollen ends up in the bacteria in the gut of bees." [pdf p77]
Likewise Aeschbacher cites a number of studies reporting the detection of foreign DNA in various cells of mammals and other production animals, including three by Schubbert et al (which are on the GENERA list #434, #435, #436). There are many studies on the GENERA list inquiring into the "digestive fate of DNA". These lines of inquiry can be of a pure research nature, but many seem to be inquiry lines to assess the practicality of requiring the labelling of animal food products fully or partially derived from GM feed; that is, if GM DNA can be detected for example in the breast of chickens then regulatory compliance with GM labelling requirements could be managed.
These 'fate of DNA' studies are not concluding on the health and safety of human consumption of GM crops. They are simply beginning lines of inquiry that, in the view of many, should have been conducted before these GM crops were released to the public.
In response to concerns such as those expressed by Kate Clinch-Jones FSANZ replied
- "It is [..] unlikely that novel genetic material will transfer from GM foods to human cells via the digestive tract." [pdf p85, point 7]
FSANZ said this despite the fact that many studies had already shown the ability of detection methods to identify high copy plant DNA in many cells of animal bodies. Indeed this Aeschbacher et al study reported finding high copy plant DNA in the liver, spleen, muscle and blood of chickens. They did not detect their largish (479bp) Bt-176 GM DNA fragment, but concluded this was likely as a result of the far lower copy number, thermal treatment of the feed, size of the fragment, and state of the art of the detection techniques, rather than indicating an absence of GM DNA in the same parts of the chickens. They predicted these fragments would be able to be detected in the future with improvements in the methods. In fact GM DNA fragments had already been detected in a chicken and pig by Nemeth et al (2004) (#344), a study supported by Monsanto, though the findings were somewhat denied (see full text). Nonetheless the prediction of Aeschbacher was verified true a year later when Sharma et al (2006) (#441) detected GM DNA of Monsanto's RR Canola (GT76) in the liver and kidney of pigs from samples retained from the animals tested in Aalhus et al (2003)/Caine et al (2007) (#1 and #66), a study already discussed in this series.
It is these type of findings in many studies of the GENERA list that lead me to frequently say that the studies report findings that are antithetical to claims made by regulators such as FSANZ.
To assuage concerns in the public and to promote the approval of the Bt-176 crop FSANZ went on to say
- "…humans have always consumed large amounts of DNA as a normal component of food and there is no evidence that this consumption has had any adverse effect on human health" [pdf p85]
But their use of such rhetoric was fallacious in that the concern related specifically to the novel GM DNA which had not ever been a part of the human diet, rather than that in our regular diet for which we could assume we had generally successful adaptive responses. The Cry1Ab-inspired insecticidal gene in the Bt-176 crop had been radically altered from the state in which it had been first identified for which FSANZ self-reported that the synthetic sequence was only 65% identical to the native gene [pdf p26]. Incidentally, the gene had also been substantially truncated.
Some years and many detections later FSANZ is still denying the capacity for novel genetic material to interact with the human system to the point where it should be comprehensively investigated prior to food approval, most recently in respect of GM crops using dsRNA constructs, despite published peer-reviewed evidence by expert practicing scientists in the field [Heinemann et al 2013]. I regard FSANZ as being active in its denial of precautionary science.