Sunday, August 11, 2013

Reading about GMOs can give you allergic reactions - An unpublished study

I resume my review of health impacts of GMOs from the Institute for Responsible Technology. I pick up where I left off: at a reference to damaged intestines.

Although damaged intestines sound like a fascinating read, I lack access to the article. What I can glean from the abstract is that they fed GM potatoes with Bt to mice and found microscopic differences in the intestines of GM-fed mice, so I tried to find similar articles/studies (although I can't tell anything about the experimental design or statistics from the abstract). One study whose abstract I read fed Bt potatoes to rats and didn't find a difference between the GM-fed and control rats. However, the study was only for 30 days, which may not have been long enough. That was the closest study I could find. With the relative absence of information on the topic, I think it's fair to say that someone should try to reproduce the results of the study, although an equally fair argument is that it shouldn't matter whether the Bt toxin is in a potato, corn, or peach, and a lot of studies have already looked at the effect of Bt-corn on mice (no... Bt peaches have not been made... I'm just craving a peach cobbler with vanilla ice cream right now).

Moving on... The next sentence goes back to allergies: "Farm workers throughout India are getting the same allergic reactions from handling Bt cotton as those who reacted to Bt spray". The citation is from a 2005 news article out of a paper in India that outlines that farmers in a district in India had allergic reactions when working with GM cotton crops, and cows had died when eating seeds from the crop. Studies have not been done and it's basically someone's opinion that these reactions were due to the crop. As demonstrated in my excellent study, which links the manufacturing of televisions to a reduction in global polio rates, just because two events take place during the same period of time, doesn't mean that they're related.

The next section states: "No tests can guarantee that a GMO will not cause allergies. Although the World Health Organization recommends a screening protocol, the GM soy, corn, and papaya in our food supply fail those tests—because their GM proteins have properties of known allergens." That last section is linked to 4 papers. Sheesh... This will take forever...
  • First paper (The use of amino acid sequence alignments to assess potential allergenicity of proteins used in genetically modified foods): no paper available or even an abstract. Based on the title alone, it's an in silico analysis. That means that the analysis was performed computationally. Computational analyses are fantastic: you can identify genes and proteins that your queried sample is similar to. They save time and definitely save money. But a computational query would be a first step in identifying similar allergens. The next step is to go out and test it. Based on the title alone, I'm assuming that the lab test was not done.
  • Second paper (Screening of transgenic proteins expressed in transgenic food crops for the presence of short amino acid sequences identical to potential, IgE – binding linear epitopes of allergens): I read most of the paper, and it's along the same lines as above. The authors recommend computationally comparing GM proteins to known allergens to give a prediction of the GM protein's allergenicity. Note the use of the word prediction.
  • Third paper: An unpublished study. Let me remind you again that a work of total fiction can be an "unpublished study". My childhood diary is an "unpublished study" on pre-adolescent behaviour. There are often times very good reasons why works of science remain "unpublished": flaws in the study's design, missing data, etc. Don't get me wrong: I have a paper that never got accepted and remains "unpublished" because I needed to do extra work in order to make the paper meatier. But I also don't pass around the paper as if it had been accepted and peer reviewed, which is what I feel that the Institute for Responsible Technology is doing here.
  • Fourth Paper: No access, but the book seems to outline concepts, not novel research. I looked at the author's CV and most of his work around the time of this paper centered around identifying GM proteins in crop using various methods. What strikes me as odd is that the book is from 1995. There has been so much work done in this field since. Shouldn't there be a more recent publication for this reference?
In summary, none of these papers demonstrate that "GM proteins have properties of known allergens", as stated by the IRT. In fact, from what I could glean, none of the papers seem to have done any allergy testing at all. However, as previous stated, there have been papers that have looked at the topic of allergic reactions in GMOs and have not found anything.

I think this is the 3rd blog that I've written that has touched on the topic of allergies. And it's a very important topic in the area of GMOs, which is why current food guidelines demand allergenicity tests before putting a GMO out on the market. Here's a blurb about allergies directly from the WHO's webpage:

"Allergenicity. As a matter of principle, the transfer of genes from commonly allergenic foods is discouraged unless it can be demonstrated that the protein product of the transferred gene is not allergenic. While traditionally developed foods are not generally tested for allergenicity, protocols for tests for GM foods have been evaluated by the Food and Agriculture Organization of the United Nations (FAO) and WHO. No allergic effects have been found relative to GM foods currently on the market."

Doesn't that directly contradict the statement from the IRT?

Next week, I'm going to skip the IRT's section on "GMOs may make you allergic to non-GM foods" because I feel like I've dedicated enough space to the topic. I'll go directly to liver problems caused by GMOs. YAY!!!





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