Transparent Information about the GMO Ingredient(s) in the “Impossible Burger”

Have you heard about this new non-meat burger that—due to an ingredient produced in a genetically engineered (GE) yeast—has a taste and “blood” like what you would expect from the real thing?

Or, since they are already commercially available for human consumption in 56 restaurants across seven American states, perhaps you’ve already eaten one?

Well, whether you are eating them daily or you’ve never heard of them, you may want to get to know them better because, as quoted in The New York Times [explanatory insertions mine], “F.D.A. believes the arguments presented [by the developers of Impossible Burger], individually and collectively, do not establish the safety of [the GE] soy leghemoglobin [it contains] for consumption, nor do they point to a general recognition of safety.” It was also reported in that article that the “agency has expressed concern that [soy leghemoglobin] has never been consumed by humans and may be an allergen.”

Yes, you read that correctly. The United States Food and Drug Administration (F.D.A.), the U.S. agency “responsible for ensuring the safety of most of the U.S. food supply,” has expressed qualms about the safety of a “key” ingredient in this new “plant-based” burger…and yet you could have one for lunch today at a Hopdoddy or Umami Burger near you.

How is that possible? you may be asking yourself. (Or, “Isn’t that impossible?” might be more appropriate in this case.)

Stephanie Strom’s NYT article is a good place to start for information on this Impossible Burger specifically, as well as for the basics on how food additives and ingredients are—or are not—regulated in the United States more generally.

Turns out, Impossible Burger and other high-tech food developers, have been interpreting a 1958 amendment to the 1938 Food, Drug and Cosmetic Act (FDCA) to mean that they can “self-affirm” a food additive or ingredient as “generally recognized as safe” (GRAS) and then go ahead and market such self-affirmed foods without consulting with, or even notifying, the F.D.A.

But advocacy groups like the Center for Food Safety and the Environmental Defense Fund do not interpret the 1958 amendment that way. EDF’s Tom Neltner was quoted in the NYT article as saying that “The [1958] exemption was meant to cover ingredients that had long been used in the food supply…. It wasn’t meant to allow companies to simply bypass the F.D.A.” And it was not, I would explicitly add, meant to exempt a protein that “has never been consumed by humans and may be an allergen.”

The U.S. Government Accountability Office (GAO) also has a problem with this state of affairs. It released a report in February 2010 titled “FDA Should Strengthen Its Oversight of Food Ingredients Determined to Be Generally Recognized as Safe (GRAS).” But, apparently, F.D.A. has yet to do so.

As I mentioned in my last post, F.D.A. and other U.S. government agencies are currently re-evaluating how foods and food ingredients developed using the techniques of modern biotechnology should be regulated. Hopefully, this major “GRAS loophole” will be eliminated as part of overhauling that regulatory process. (But I, for one, am not holding my breath.)

In the meantime–and especially since Rachel Konrad, a spokesperson for Impossible Burger, informed the NYT that “we believe the public wants and deserves transparency and access to any information they need to decide for themselves whether any food they might eat is safe and wholesome”–below you will find additional information about the GE soy leghemoglobin (etc.) in Impossible Burgers:

  • Konrad stated that “A key ingredient of the Impossible Burger—heme—is an ancient molecule found in every living organism.” But the GE protein that releases that heme in Impossible Burgers when they are cooked–soybean leghemoglobin produced in a GE yeast strain–is a protein naturally found in soybean roots that, as mentioned by the F.D.A. (and noted in the NYT article cited above), “has never been consumed by humans.” It therefore only seems sensible that F.D.A. should not allow a protein that has never been consumed by humans to be self-affirmed by its developer as GRAS.
  • In a document acquired from FDA through the Freedom of Information Act (by the ETC Group, a Canadian environmental organization, and shared with the NYT), Impossible Burger argued that soybean leghemoglobin “is substantially similar [my emphasis] to proteins consumed daily by the global population, in the form of meat and other vegetables” and that “Impossible Foods does not believe that consumption of this protein presents any issues of safety to the consumer.” But this is not a scientifically sound argument, and F.D.A. noted in the FOIA-acquired document that discussion of proteins other than soy lehemoglobin “is not relevant” to safety assessment of the Impossible Burger; and that is because for proteins, even “a relatively small difference in sequence or PTMs [post-translational modifications] can result in a large difference in function, which can be important in predicting protein functions, regulation of protein functions, and in the evolution of new functions” (Jeffery 2016). This “substantially similar” argument comprises a whole new level (a new order of magnitude?) of the “substantial equivalence” argument that has been used by the developers of GE foods up until this point in time. It is an argument that has no basis in protein science as related to safety evaluations and, in my opinion, rather than GRAS, Impossible Burger’s leghemoglobin could be considered a food additive and regulated as such at F.D.A.
  • Additionally, Impossible Burger told FDA that the soy leghemoglobin will be extracted from GE yeast “cells and purified away from other cellular proteins, with a resultant purity of approximately 73% leghemoglobin. The non-target proteins which may co-purify are expected to be safe for consumption based on history of safe consumption of the whole yeast in animals.” But among the many non-target proteins that “may” co-purify with the GE leghemoglobin, Impossible Burger lists “Hypothetical proteins” and “Unnamed protein products.” Impossible Burger may expect those hypothetical proteins and unnamed protein products to be safe, but that doesn’t mean that consumers like me have to.


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5 Responses to Transparent Information about the GMO Ingredient(s) in the “Impossible Burger”

  1. Ed Regis says:

    It is notable that neither the Times piece nor your own post mentions any illness, allergic response, or indeed any other adverse health effect attributable to the consumption of Impossible Burgers. This is in line with years of experience in the consumption of GM foods more generally.

    • Belinda says:

      In nearly 30 “years of experience” there have been troublesome GE “foods.” There was the case of StarLink corn, for example, in which the EPA’s concern about human allergenicity prompted the agency to originally approve it only for animal consumption, and when the GE Cry9C protein it produces was found in taco shells and other human foods in grocery stores it was pulled off the market; EPA, FDA and CDC remained concerned enough about that GE food that the U.S. corn crop was monitored for the presence of Cry9C for another seven years.
      I also feel the jury is still out on NK603 corn; additional long-term animal-feeding studies–with more controls–should be carried out with that GE food to determine whether previously identified but “inconclusive” concerns are still of concern.
      GE crops/foods should be evaluated for safety on a case-by-case basis. Impossible Burger is no exception.

      • Ed Regis says:

        I have no problem with GE foods being evaluated for safety on a case by case basis. But it would make more sense to likewise evaluate foods that are a product of conventional breeding methods whose operation is not fully understood even today, such as for example foods produced by chemical mutagenesis, radiation breeding, somaclonal variation breeding, or that oldest and least understood of all breeding methods, grafting. StarLink corn, as you know, after being thoroughly investigated by the CDC, was found never to have killed, harmed, or even produced an allergic reaction in anyone. Finally, I do not see why scare quotes are needed around “years of experience,” or, of all things, “foods.”

      • Belinda says:

        I’m glad to learn that you have no problem with safety evaluations of GE crops/foods on a case-by-case basis; unfortunately, however, that is not the current situation in terms of required regulation of GE crops/foods in the United States.
        Some years ago, Henry Miller proposed an evaluation system for GE crops/foods that would also cover those produced using conventional breeding methods, and I think that such a system is an option to consider. Of course, GE crops are produced using a form of mutation breeding (insertional mutagenesis) and are subject to somaclonal variation during the regeneration process, facts which should be taken into account whatever the evaluation process.
        I am not an immunologist but my understanding is that developing an allergy involves exposure, sensitization and surpassing an allergen threshold–a process that takes time. The CDC investigation of the potential human allergen in StarLink corn was conducted soon after contamination of the U.S. corn crop first occurred and, to my knowledge, only that once. Perhaps that is why the bottom line was that CDC/EPA could not rule out the possibility that Cry9C could be a human allergen and, perhaps, why the U.S. continued to monitor levels of Cry9C in the U.S. corn crop for another 7 years until levels were deemed unworrisome.
        I am not familiar with the concept of “scare quotes.” I hesitate to call them “years of experience” since we would have a whole lot more experience if we had evaluated, regulated and monitored the products of genetic engineering that have been introduced into our agricultural system more thoroughly over the course of the last few decades. Troublesome GE products have not always been “foods;” e.g. there was the case of the GE corn that produced a pig vaccine; that GE product was not meant for consumption as a human food but became troublesome when vaccine-producing GE corn volunteers came up in a soybean crop grown later in the same field, contaminating that crop which was intended for human food or animal feed.
        While I prefer to concentrate on substance rather than punctuation, next time I consider using “quotes” I will keep in mind that some people may find them scary.

      • Ed Regis says:

        Fair enough.
        As for scare quotes, I don’t find them scary. They’re sort of prejudicial. Here’s what they are:
        scare quotes
        quotation marks used around a word or phrase when they are not required, thereby eliciting attention or doubts.
        “putting the term “global warming” in scare quotes serves to subtly cast doubt on the reality of such a phenomenon”

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