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  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.