Wednesday, June 26, 2013

No high fructose corn syrup in Monsanto's response to Seralini

In my first blog article, I promised to review Monsanto's response to the Seralini et al article (2012). Interestingly, the European Commission was alarmed enough about Seralini's study to request that the European Food Safety authority take a look at the study as well. So, I (hope) to take a look at both of these articles in this post.


Monsanto's response is pretty brief. It's only 7 pages (including summary) in fairly large font size and 2 pages are dedicated to references. Not your traditional scientific style. My guess is that it was written in a format that would make it easy for reporters and analysts to view and read. There are two large sections:
  • Plausibility and Weight of evidence. In this section they give a point by point breakdown of findings that contradict previous studies or are highly unlikely given the number of studies that have been done in the past. These include studies showing that glyphosates don't cause cancer and have no side-effects (glyphosate is the chemical in Roundup). I thought that these were good points, but still, there's the possibility that Seralini might have discovered something new. The strongest point in this section was Monsanto's argument that there's no plausible mechanism to explain how the DNA from the corn OR the protein that confers Roundup resistance might cause cancer.
    • In my opinion, this is a really strong argument. Obviously, the DNA from the cells we eat don't do anything to us. Otherwise we wouldn't be able to eat anything, whether it's GM or not. The modified proteins that come from GM plants get digested the same way we digest any other protein. Our stomach and intestines don't know the difference (if our stomachs were that smart, I would totally start working on a way for my stomach to not breakdown chocolate or other delicious treats.... Mmmmm... Chocolate...). I did look it up and found two studies that have looked into the digestion of the protein that confers Roundup resistance and it seems to get chewed up pretty quickly in the gut, so at least Monsanto was accurate there.
  • The second section commented on Design, Conduct, and Interpretation of Seralini's study. This section was a bit painful to read, only because I kept putting myself in Seralini's shoes. It's tough getting your work criticized, harder still getting it torn to shreds. I honestly don't know if Seralini chose to omit findings and statistics from his papers, but if he didn't and it was a genuine mistake, then reading this section of Monsanto's response would have been very painful. Monsanto was not rude, cruel or critical. Monsanto was to the point and didn't sugar coat anything and used phrases such as "no data at all, let alone any summary statistics, are provided". As a person who used to recoil at the sight of her professor's red pen, statements such as those can make deep cuts. But let's get back to Monsanto's retort:
    • I was happy to see that Monsanto highlighted many of the same issues I pointed out in my first post: no statistics, missing data, not enough rats used, no link between dosage and symptoms/severity, etc. 
    • There were a couple of items that I was very surprised to learn. The most shocking one is that the rat strain used in the study has historically high rate of tumors/cancer. Thus, Monsanto argues that the numbers that the authors provide for the incidence of tumors fall within the norm for the strain. I looked it up and it's apparently true: a study in Cancer Research looked at 150 female rats of the same strain used by Seralini. 57% of the rats developed tumors throughout their life-span and they were raised on standard lab feed. 95% of the tumors they observed were in mammary gland tissues. Before you argue that it's possible that standard lab feed has GM corn, you should know that the paper was published in 1956. Another paper published in the 70's found that the incidence of spontaneous tumors was 45%. Again, they state that the females had double the tumor rate and this was primarily due to mammary tumors (that's almost verbatim a sentence from my first blog listing Seralini's "findings"). Wow. I can't help but feel that Seralini was outright deceptive. If I was able to find those two papers and get the highlights of their conclusions from a 5 minute websearch, Seralini had no excuse. Unless he was doing his research in North Korea. #sleezy
    • Monsanto pointed out a few times how the data was highly selective: for example, the authors only provide information on kidney tumor incidences in males, but not females. I thought that this was a very valid point. In today's electronic age and high-throughput sciences, it's a standard practice to post your data online so that people can download it and analyze it for themselves. But this wasn't done for Seralini's paper. Why, oh why???
Well, I was told that my first post was really long, so I'll skip the European Commission's review and leave it for next week. After reading these two articles, here's my conclusion: I think Seralini has a point in stating that long-term studies have not been done for GM crops. However, his study wasn't done well. At best, it was incorrect and inaccurate. But at worst, it was deceitful. Yet there's nothing inaccurate in Monsanto's response. At this point in time, Monsanto is being so carefully scrutinized that they can't afford to lie in a press statement. Sure, they can be sleezy and quietly pass legislation through Congress. However, I think that if they were to publish ANYTHING that could be refuted, anti-GMO groups would be all over them (that's not to say that we shouldn't examine what Monsanto publishes very carefully). But I think this is probably why their response to Seralini was so dry and in bulletform.

For your reference, here's Monsanto's response:
A summary of their response can also be found on their website:

Wednesday, June 19, 2013

The first blog article!! Roundup 'em GMOs!

My first blog article... If you're wondering why I've started this blog, please see the Mission and FAQ section of the page.

So, for my first article, I selected "Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize" published by Seralini, et al, in Food and Chemical Toxicology in 2012. This is one of the few articles I could find in pubmed which referred to health impact of GMO and has been a cornerstone in the anti-GMO movement.

As you can imagine, Monsanto wrote a list of counter-arguments to Seralini's findings. There are a lot of other articles critical of Seralini's paper, and I'll take a look at those later on. At the same time, Seralini recently wrote counter-arguments to Monsanto's counter-arguments, so I'll read that later on, too.

  • Seralini et al perform a 2 year detailed rat feeding study (if you disapprove of using animals in scientific studies, you'd better stop reading!).
  • The rats were fed the Roundup (R) tolerant NK603 strain of corn, developed by Monsanto. The control mice were fed the closest strain of corn that had the absence of the Bt transgene (for more info on Bt, please see
  • The R-tolerant (i.e. GM) corn was split into two groups: one was treated with Roundup and one was not. Then they made rat-food with different amounts of the GM corn which was grown with or without Roundup: 11, 22, and 33% corn. An additional variable they looked at was the presence of Roundup in drinking water.
  • In total, there were 10 groups of rats. 100 male and 100 female rats were split randomly into the groups.
    • Plain water, plain corn
    • 11% GM corn without R
    • 22% GM corn without R
    • 33% GM corn without R
    • 11% GM corn with R
    • 22% GM corn with R
    • 33% GM corn with R
    • Plain corn, Dilution 1 of R in water
    • Plain corn, Dilution 2 of R in water
    • Plain corn, Dilution 3 of R in water
  • Blood and urine samples were examined from the rats. When an animal was sacrificed, a whole slew of organs were examined.
  • Authors present a plethora of findings (I love that word... Plethora... Always reminds me of the Three Amigos). I'm plagiarizing directly from the paper in a few of the sentences listed below. There are plenty of more findings, but these are the ones that stood out to me:
    • More rats died in the groups of rats whose diets had the GM maize.
    • Females who were drinking the R-treated water had shorter lifespan
    • Females had more frequent tumors than males, the majority of them being mammary tumors.
    • Up to 14 months in the study, none of the control rats had tumors while 10-30% of the females had tumors with the exception of the 33% GM + R rats
    • Authors provide lots of pictures of rats with giant tumors
    • In females, androgen/estrogen balance was modified.
    • None of the findings were proportional to the dose of treatment
    • Authors note that animals fed NK603 without Roundup (R) application also had enhanced tumor incidence and mortality rate. They hypothesize that this may be due to the imbalance of two metabolites (these are molecules that control metabolic pathways), which they had found to be significantly decreased when compared to controls. (If you aren't sure what was done here, it's basically the same thing that your doctor does at a checkup: blood work and urine analysis. The authors of the paper looked a lot of different variables including things like glucose, cholesterol, hemoglobin, etc, and found two factors that were significantly different from controls).
    • Death in males was primarily due to messed up liver and kidney function. Again, they attribute this to the imbalance of the two metabolites.
    • The authors found that GM maize fed groups with or without R application had decreased mRNA transcription because the DNA was packed more tightly.
    • The authors note that the concentration of Roundup used to treat the rats was way below the limit set by the EPA, yet there were "severe hormonal-dependent mammary, hepatic, and kidney disturbances".
You're probably thinking "Yowzers!". But before you dump all your Coca-cola, which is probably made with high fructose corn syrup extracted from GM corn, down the drain, keep reading.

Holy missing statistics, Batman!

Here are my thoughts, but I can summarize this by saying that there's a reason why the paper was published in a journal whose impact factor was 3 (and for all you conspiracy theorists, it wasn't Monsanto paying the publisher to get the article quashed). As a comparison, the New England Journal of Medicine's impact factor is 53.
  • Dudes, how could you publish a paper without doing any sort of statistics for your findings?? The only place where statistics were performed were for the biochemical analyses, and I believe that they did stats only because they were fishing for something. They found significance in only two secondary metabolite levels and they blamed all the findings in the paper on these. When reviewing this article, my hubby pointed out that he didn't take stats 101, so I should explain why this is important. Here's my feeble attempt: Statistics basically allow you to determine is something is random or not. God knows how many times I thought that I had discovered something important, but when the numbers were crunched, there was nothing there. For example, I clearly remember a case where I found a DNA mutation in a large number of the patients I was studying, and it was present at a seemingly less frequency in the controls. When a statistical analysis was performed, it was not found to be statistically significant. Meaning that it was random. If I had a completely different group of patients, there was a good likelihood that the mutation would have been present in the same frequency as the controls. That's why stats matter. The control mice DID get tumors. The question that stats have to answer is whether the treated mice got more of them and whether it was sooner.
  • Why in the world wouldn't you do more work to explain why there's no link between dose and findings (I hate to call them "findings" since no stats were done)? The authors claim that there's probably a threshold, and that they hit that threshold with the lowest dose. (11% GM) If that's the case, then they should have looked at anything lower than 11% to see if that's true. Also, if your hypothesis is that the tumors are due to imbalances in the metabolites, then you could have even done an in vitro study. They might have even seen the imbalance by feeding the rats just one time, yet they failed to do it. The worst part of the whole thing is that there's no explanation why the most concentrated doses fail to exhibit symptoms. #epicfail
  • If their hypothesis is that the imbalance in the metabolites causes tumors in the mice, then they should have looked at the metabolite levels in the rats that developed tumors vs the rats that didn't.
  • Ideally, I think they should have more rats. There's only 10 rats of each gender in each group. When the authors make statements like "10-30% of the females had tumors" that means that only 1 rat had a tumor in one of the groups. I think that it's for this reason that the stats weren't presented.
  • My final point is just a personal bias: as a geneticist, I would have liked some attempt at explaining why the authors observed different DNA packaging.
My final conclusion is that the authors may have something here. However, until they do the statistics and demonstrate significance (not just an observation), then there is nothing. In my opinion, any anti-GMO article that cites this paper with sentences such as "Monsanto corn causes cancer" should be ignored. There's no evidence of causation or even association.

I'll review Monsanto's rebuttal next week.