Review of "Compositional differences in soybeans on the market: Glyphosate accumulates in Roundup Ready GM soybeans"

Soy bean field with irrigation system.
Wikimedia Commons. Image by Dwight Burdette.

A friend asked me to review the paper entitled "Compositional differences in soybeans on the market" (free available here), so I thought I'd make my comments publicly available. I'm going to read the paper first, provide comments as I go along, and then find reviews online (if any exist).

The paper starts by outlining the principle of substantial equivalence, meaning that GMOs have the same nutritional content than their unmodified counterparts. The authors outline that studies examining substantial equivalence for Round-Up Ready soybean were performed early on, but not when treated with Round-Up. A follow-up study found substantial equivalence when the soy was sprayed with Round-Up, but didn't examine how much glyphosate accumulated in the plant. It is the authors' hypothesis that this is a flaw and their study is designed to examine this question (i.e. is GMO Round-Up Ready soy substantially equivalent to its non-GMO counterpart when sprayed with Round-Up, and how much Round-Up accumulates). They hypothesize that high levels of glyphosate may affect plant metabolism. The authors point out that USDA data highlights that glyphosate use is increasing, so this question is all the more important.

I pause here to note that the authors do not clarify if this is glyphosate use per acre, or total glyphosate use. If I owned a house with 0.5 acre backyard ten years ago and now owned a house with 10 acre yard, and I used weed killers on both properties, then of course the total amount of weed killer I used would show an increase, simply because I have more land. But that may not mean that I've been using more weed killer per acre.

In their study, they examine 31 samples of soybeans grown in the state of Iowa to examine their two questions. They examined 3 different types of soy:
1) Round-Up Ready Soy
2) Conventional Soy possibly sprayed with other pesticides
3) Organic Soy bean which would have no glyphosate residues

The authors then list the variety of soy bean and how they were grown. They collected 3 kilos of soy from 31 different farmers, and it seems very odd to me that they'd select different varieties of soy and different methods of treatment for each category. Why wouldn't they try to find 31 farmers that used the same type of seed? The authors don't specify if the conventional soy is the isogenic variety to the Round-Up Ready soy. This is a key issue given the question they're trying to answer: for example, if I did a study on apples and collected apples from 31 different farmers, you'd want them all to be of the same variety rather then having some Red Delicious, some Fuji, etc.  Otherwise, it's not really an apples to apples comparison. Ha!! Get it???

So, they did a bunch of analyses on the soy beans. They found residues of glyphosate and one of the compounds it breaks down into in all the GM-soy, but not the conventional or organic (oddly enough, their graph doesn't have error bars...). Then, they did statistics on nutritional content and the authors highlight some of the differences (it's also worth nothing that they highlight measurements where the organic category had higher measurements, but not where GM/conventional had higher measurements). The authors then cluster the soy samples based on the results and find that the three different categories tend to group together.

Then the authors go on to reject the null-hypothesis of substantial equivalence. They highlight that their paper identified glyphosate residues in the crops at higher levels than had been hypothesized. They highlight the "toxicity" of Round-Up by citing Seralini (minus 200 points for citing Seralini).

My main comment, as I've mentioned in the past, is that substantial equivalence does not mean identical: "Substantial equivalence is often confused for identicality, however, the Food and Agricultural Organization of the United Nations states that substantial equivalence “is established by a demonstration that the characteristics assessed for the genetically modified organism, or the specific food product derived therefrom, are equivalent to the same characteristics of the conventional comparator. The levels and variation for characteristics in the genetically modified organism must be within the natural range of variation for those characteristics considered in the comparator and be based upon an appropriate analysis of data”" (emphasis has been added)

Also, the levels of glyphosate are provided and the authors point out that these are below the maximum permissible levels. So I'm not sure what their problemo is.

So, I searched for reviews of the paper and found one on GMOanswers, written by someone at Monsanto. They too, made the same criticism as me about the seeds: "When the authors collected the soybean varieties for this study, they separated them into the three groups — organic, conventional and GM. Unfortunately, each group contained different soybean varieties, with no overlap (with one exception) of varieties between the three groups, so each group was already inherently different from the others. Even the authors acknowledge that different varieties can have widely different seed composition. Therefore, concluding that any differences between the groups in this study were due to the way the soybeans were grown (organically or not), or the presence/absence of a glyphosate-tolerance gene in the GM varieties, is simply not possible. The three groups are expected to produce different results because they started out with different genetics."

GMOanswers also notes the fact that they were grown in different farms: "Since the plants in this study were not grown together but rather taken from separate fields across a region spanning a 200 km radius, any real differences between the three groups can’t be separated from the variation caused by location, and no reliable conclusion about their nutritional quality can be made. To put this in context, we are looking at satellite imagery to help farmers make more-informed decisions by increments of meters, not miles." I agree with this point, but having a bunch of crops that were grown in the same area could have provided some information if they were the same type of seed. But since they weren't, the different farms makes matters only worse.

GMOanswers puts the findings within the context of natural variation, which I appreciated: "Finally, when we take into account the effects of genetics and location, we see that the compositional differences the authors observed in this design are not unexpected. Protein levels in soybeans generally average ~40 percent dry weight (dwt) but have been shown to range naturally from 34.1 to 56.8 percent dwt (Wilson, 2004). This natural variability can be due to variety, location or environment, and it means that people are already consuming soybeans with larger variability than the differences in soybeans reported here."

The reviewer also notes that glyphosate residues were within permissible levels and then there's a blurb about the safety assessment of pesticides, yada, yada, yada... He also noted the slant that the authors have in not really discussing what pesticide residues in organic food means.

Amelia Jordan, whom I've interviewed in my series "Better Know a Scientist", did a review on Skepti-forum, and highlighted several other issues: the fact that there's no information on how the organic crops were treated, how the soil was treated in any of the farms, and very importantly, the
fact that 31 samples for a study with this much variability in a number of factors is very, very low.

All in all, I don't think the study is conducted well enough to draw any meaningful conclusion, especially not the one that they're trying to draw which is that organic food is "better" than GM. Their finding about glyphosate is interesting and I think that future studies that examine compositional differences between pesticide/herbicide tolerant crops and controls should do similar analyses, but the measurements in this study have been deemed to be safe.

Interview with BioChica on labeling, organics, and GMOs

A couple of weeks ago, a student from USF reached out to me for an interview for an assignment that she had. She had a series of questions about labeling, organic food, and GMOs. Once I had answered her questions,  the spouse suggested that it would be good to share my responses on my blog (with a few edits), because it summarized my thoughts on quite a few topics.

Q: Why do you think there is a debate about GMOs vs. Organic or natural produce?

I think that it's because GMOs are feared as being “unnatural”. The idea of taking a protein from one species into another seems like something out of a science-fiction novel, particularly since the general population associates bacteria and viruses with harm and danger. So taking a gene from a bacteria and adding it to a plant has an "ick-factor" or a certain amount of "unnaturalness" associated with it. This fear has been harnessed by activists into campaigns against GMOs. Some of these groups are organic food proponents, such as the Organic Consumers Association or Only Organic, creating a false dichotomy of GMO vs organic.

However, many farmers grow both conventional and organic crops. The dichotomy does not need to exist, and in fact, some GMOs could be grown using organic food production practices if the label allowed it.

Q: Do you have a stance on the GMO vs. organic issue? How did it develop?

My stance on GMOs vs organic has evolved quite a bit. I never really had an issue with GMOs and I started blogging to learn more about them. So to be more accurate, my stance was with respect to conventional food vs organic food. The reason why I never had an issue with GMOs is because I don't view a protein or gene as "belonging" to a species. Genes get copied, erased, and shifted around all the time throughout the evolution of a species (actually, here’s a picture about one of my publications in grad school that outlines that the gene I was working on was copied in placental mammals, but not in marsupials). So I actually view the process of transgenesis (which is generally used to make GMOs) as more accurate, because you can select exactly what gene you want to copy or erase rather than letting it happen randomly (which is what happens when we crossbreed). When I started reading the scientific literature on GMOs, my mind was completely put at ease about the GMOs in our food supply, so I eat GMOs and feed them to my family.

Regarding organics, when my son was born, my primary concern was the level of pesticide in our food. I began feeding him organic veggies, because I thought that they were pesticide-free. As I learned about our food and found out that organic food production does use pesticides, I was really taken aback. I read the recommendations from the FDA and USDA, and learned that washing fruits/veggies with cold water gets rid of pesticides, regardless of the method used to grow the crop. When I saw the actions of groups such as the Organic Consumers Association and the misinformation they spread about GMOs, I boycotted organic food entirely.

Now, I've come to realize that all forms of food production have pros and cons. Farmers should be free to grow their crops with whatever method they find suitable, following laws and guidelines set forth by regulatory bodies. This creates a wealth of different foods grown using different styles. I try to buy what's in season from California (since it’s where I live), and I try to buy at the best price point, regardless of whether the food is grown organically or conventionally. At the moment, most of our fresh produce is conventionally grown. All the meat and dairy we buy is conventional. Some of our dry goods, particularly my son’s snacks, are organic (Costco has amazing deals on organic snacks for kids).

Q: In your opinion should GMOs be labeled?

This is another topic where my opinion has changed a lot over time. I started out thinking that if the general public wants labeling, then it should be provided. I didn't understand why companies would fight it. My opinion changed due to several reasons:

• Risk perception: A label stating "May contain GMOs" conveys the idea that GMOs may be harmful, which is why food manufacturers fight the label.
• Cost to suppliers/farmers: if we're going to start separating GM food from non-GM food, we’d have to start separating them from the source, and most of that burden will fall on farmers. They will have to have separate equipment, separate storage, separate transportation, etc for GM and non-GM crops, which will significantly increase the cost to farmers and the cost will probably trickle down to consumers. The cost of changing the label itself is not significant, but the cost of segregating crops will be burdensome.
• Defining what needs to be labeled: There’s no consensus on the definition of a GMO ingredient (here’s a recent post that I wrote on the topic). There are so many different criteria and examples: do we label the meat from a cow fed GM grain? What if the cow received a GM vaccine? Do we label sugar derived from a GM-beet, even though it contains no DNA or protein and is therefore indistinguishable from sugar derived from a non-GM beet? How much of a GMO needs to be present for an item to merit being labeled? There’s absolutely no consensus on what should be labeled.
• Labels already exist: if individuals are genuinely concerned about GMOs, then they should just buy food under the USDA’s organic label, which already excludes GMOs, ingredients derived from GMOs, and animals raised on GM-grains. Why do we need to go through the expensive legislative and burocratic process of creating a label for individuals who want to avoid GMOs, when there’s already a label in place to meet their needs?
• Arbitrary nature of the label: the demand to label GMOs is basically a demand to label how a crop was made. It doesn’t provide information on the amount of pesticide used, on the conditions the crop was grown in, or anything that might genuinely be informative. So why is there a demand to label transgenic crops, but not any other methods to develop crops, such as mutagenic crops (derived by radioactivity or mutating chemicals)? Crops derived through mutagenesis are accepted under the USDA’s organic label, so you couldn’t avoid them even if you wanted to. It doesn’t make much sense and seems completely random.

Q: What is the number one misconception you hear repeated over and over again about GMOs?

“GMOs aren’t tested. We’re the guinea pigs”. There’s a very large number of publications on the GMOs in our food supply and they range from animal feeding studies to environmental impact studies to tests/assays on identifying GMOs in our food supply. I understand the hesitation to trust data generated from the companies that develop GMOs, but many of these studies are carried out by independent researchers. You can find many of these studies in GENERA.

Q: Are GMOs harmful or helpful to our world’s food economy?

“GMO” is a (non-scientific) term used to denote that a crop is made through transgenesis. But the gene/protein/trait introduced into the crop varies. So GMOs should not be lumped all together into a single category: their value, pros, and cons depend on the trait that was introduced.

For example, the Rainbow Papaya is a transgenic crop made to resist the papaya ringspot virus and revitalized Hawaii’s papaya industry. It has made a significant impact to the State’s economy and to its farmers. It’s a great example of how a transgenic crop can benefit a region’s economy.

Q: What inspired you to begin writing about GMOs?

When California had its labeling bill on the ballot, I started seeing a lot of contradictory information in the media on GMOs, particularly in social media. I thought that the responsible thing to do would be to go and read the original research papers myself and find out the truth of the matter rather than rely on someone else to tell me what’s true. Soon after, my husband and I had the opportunity to travel to Cambodia, and I learned a lot about their struggles to rebuild and how they were working with the International Rice Research Institute to try to increase their yields. I wanted to learn about how it was done, and it was what I needed to buckle down and start reading. I started writing just to document my journey and to share it with family and friends, so it’s been a surprising turn of events that has led me down a path where I find myself writing for larger audiences.

Q: Where do you see the GMO labeling debate heading in the future? Do you think there will ever be an end to it?

I think that the solution might be a Federal law on voluntary labeling, and I believe that most agricultural biotech companies as well as food companies would support such a law (one has actually been proposed. Read more about it here). However, that won’t stop the campaign of misinformation about GMOs. I genuinely do not know what the solution is to the latter and doubt that there will ever be an end to it. After all, there are still people who believe that vaccines cause autism and there are still groups that promote such ideas, despite the overwhelming amount of information and data to the contrary, so I don't think there will ever be an end to it in that sense.