By Henry Ehrlich
I read an article in the morning paper about a product called “Impossible Burger,” which is the darling of certain high-end restaurants for tasting and feeling like beef but being made entirely from vegetable sources. Invented by a Stanford chemist, Pat Brown, it has half the cholesterol of beef (I guess from coconut oil, which is bad for us) and a fraction of the carbon footprint and water consumption. Thus, the Silicon Valley appetite for disruption comes to the dinner table.
The key protein, leghemoglobin, which is found in small quantities in both meat and vegetables, and is abundant in the roots of soy. It is cultured by adding it to yeast by genetic modification. When heated, leghemoglobin produces something called heme. It contains iron in it (think hemoglobin) and is found in animal blood and vegetables. In Impossible Burgers it accounts for the taste and texture that burger lovers adore.
The gist of the article is that the FDA wants more evidence that leghemoglobin is not allergenic because it doesn’t appear among the many components of soy, which is a charter member of the top 8 in America. Soy and wheat are already listed on the Impossible label.
One of the fun things about editing a website is that around the clock somewhere in the world an expert is taking a break from work and checking their Twitter feed. When I am reading my morning New York Times it’s lunch time in the UK, so for perspective I reached out to our contributor Adrian Rogers, an expert on testing for allergens.
This was the first he had heard of Impossible Burger, too, but armed with access to a powerful data base, he supplied me with a staccato feed of information and commentary that calls into question the FDA’s assertion, expressed in the Times, that more study is required. Adrian said that plenty of work had already been done by the Food Allergy Resource and Resource Program (FARRP) at the University of Nebraska and he sent me a paper that was submitted to the FDA in 2014.
The paper acknowledged that soybean leghemoglobin is not identified among known soybean allergens, which may be the source of the FDA’s extreme caution. However, the expert panel offers assurances based on Impossible Foods hiring Dr. Richard E. Goodman of FARRP. “Dr. Goodman conducted a comprehensive search of the biomedical literature to identify any published reports regarding possible allergenicity or toxicity associated with hemoglobin proteins and any reports regarding health issues associated with human consumption of hemoglobin proteins of any origin. Dr. Goodman concluded ‘My conclusion from this weight of evidence’ approach to dietary protein safety is that the soybean leghemoglobin is very unlikely to present a risk of dietary allergy or toxicity to consumers.’”
In an exchange of letters found in the public record in 2015-6, the FDA did appear to be reassured and back off from further investigation. Why this has become an issue again escapes me. Six-hundred or so allergenic proteins are well known and can be avoided in the manufacture of new foods. Impossible burgers may be vegan but they aren’t “natural.” Adrian suggests that the proteins could cross react with other allergens that wouldn’t fall under the soy heading, although it is unlikely since he says that one of the FARRP investigators, Steve Taylor, “is a God of Allergen Detection.” Regardless, he says, “The study follows current best practice guidance, and the ‘meat’ contains soy protein anyway so those with soy allergy will avoid.”
In my last Tweet of the morning I wrote, why are the regulators suddenly so worried that this ended up in the pages of the Times? He wrote: “Maybe the meat industry is worried.”
Pass the ketchup.