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I ate an Impossible Burger – wish I hadn’t

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Update: the latest version of the Impossible Burger is now made gluten free without wheat, which is a welcome change. Thanks to our readers for bringing this to my attention. Despite the fact that the Impossible Burger has been rumored to contain glyphosate (I have not seen a definitive test as of yet), I will plan on eating another Impossible Burger now that it is gluten free and update this review when I do. This review is based on my experience eating version 1.0, which did contain wheat.

A few days ago at a promotional event, I had the chance to sample an Impossible Burger, the popular Vegan “hamburger” whose mission is to make meat obsolete by 2035. Initially, I was impressed by the resemblance of a plant based burger to an actual burger, however, after I learned the ingredients they use to make Impossible Burgers, I regretted my decision to partake in this burger coups d’état.

But before I get into a discussion of why eating Impossible Burgers is probably bad for you, I do want to give them some props because I believe their heart is in the right place.

The Impossible Burger is environmentally friendly, that much cannot be disputed. Raising cattle the way we do does real damage to our planet, and it has to stop, at least at its current trajectory. The industrial farming system is unsustainable, environmentally ruinous, and cruel to both animals and humans alike. Companies like Impossible Foods that create tasty plant based comfort food are badly needed.

I just wish they hadn’t made their plant based salvation burger with common food allergens and Frankenstein yeast byproducts.

Just because it’s made of plants doesn’t mean it’s good for you.

Impossible burger designed to look like real burger

As I allude to above, the Impossible Burger is designed to look and taste just like a real burger. This means the inventors were challenged to use plant matter to make a moist, “bloody” patty, with the same texture as real meat. To be fair, I must admit the Impossible Burger is reminiscent of a real burger, it has a texture and color that looks like ground beef. The aesthetic is impressive. The problem is that it uses truly gross ingredients to get there, ingredients that could be just as bad for some people’s health as eating a real burger every now and again.

In fact, there was some controversy as to whether the FDA would even approve the ingredient, called soy leghemoglobin, that makes the Impossible Burger “bleed.” Soy leghemoglobin releases a protein called heme which gives the burger it’s meat like traits.

The FDA was was concerned about soy leghemoglobin, because well, it’s never been consumed by humans!

Seems reasonable to me, and keep in mind, this is coming from an organization that has zero qualms about high fructose corn syrup and genetically modified crops, so it’s not like there is a high bar to get the FDA’s blessing.

Lack of human studies – heme is not leghemoglobin

Is soy leghemoglobin safe?

No one knows for sure, and the answer likely varies from person to person, however, the Impossible Burger team did feed unbelievable amounts of soy leghemoglobin to rats and found there were no adverse effects over a 28 day period.1

We don’t have studies in humans to see how people will react to the ingredients in the Impossible Burger.

It’s also worth noting that leghemoglobin, hemoglobin and myoglobin are not the same thing. They might all function to bind oxygen but they do all have a different structure. So, leghemoglobin is not the exact same molecule found in actual meat. They are similar but not identical.

Genetically modified microorganisms

So, to make this soy concoction, the Impossible Burger folks must be ripping through a ton of soybeans, right?


They get their Frankenstein soy from genetically modified species of yeast. According to this Wired Article, “one acre of soybeans yields just a kilogram of soy leghemoglobin,” so the Impossible Burger team created a workaround.

It’s hilariously complex, but Wired does a good job of summing up the process:

Technicians take genes that code for the soy leghemoglobin protein and insert them into a species of yeast called Pichia pastoris. They then feed the modified yeast sugar and minerals, prompting it to grow and replicate and manufacture heme with a fraction of the footprint of field-grown soy.

Ok, so we aren’t even eating soy from soybeans, we’re eating a soy / yeast byproduct combination made from genetically modified microorganisms?

And I do think this is an important distinction to make here. The Impossible Burger doesn’t just use genetically modified ingredients, it produces its key proteins using genetically modified microorganisms. I am not saying that is necessarily a bad thing, it may be a necessary thing in light of what animal agriculture is doing to the environment. However, we don’t know how people will react to eating these ingredients because they have not been in the food supply. This is not an “anti-science” position as some have claimed in the comments. Instead it is a recognition that the Impossible Burger is largely pre-science. They simply haven’t had the time to study the impact of the new proteins they are making on any one other than some very unlucky rats.

Further, the heme protein isn’t the only protein the yeast make. They make 40 others, all of which end up in the Impossible Burger, and none of which have been studied in the human body.

Do I think all of these proteins are dangerous?

Probably not.

But I do suspect that there will be a subset of the population that will have sometimes violent allergic reactions to this product and that has been proven by the comments on this post, this one being a good example:

I like the burger but I had multiple reactions to eating. I tried it a 2nd time to confirm it was the burger. I get immediately nauseated and crazy bloating like the stomach flu, diarrhea, vomiting and nothing helped. It has to be an autoimmune response. I eat all kinds of veggie meat including the beyond burger and no trouble. I did advise the company and they actually had a CO and physician contact me to ask about by medical history. But that’s just me…

Impossible Burger Ingredients

Update: gluten is no longer an issue. The Impossible Burger 2.0 is now made without gluten.

It’s not just GMO soy, these are the other ingredients in the Impossible Burger:

Water, Soy Protein Concentrate, Coconut Oil, Sunflower Oil, Natural Flavors, 2 percent or less of: Potato Protein, Methylcellulose, Yeast Extract, Cultured Dextrose, Food Starch Modified, Soy Leghemoglobin, Salt, Soy Protein Isolate, Mixed Tocopherols (Vitamin E), Zinc Gluconate, Thiamine Hydrochloride (Vitamin B1), Sodium Ascorbate (Vitamin C), Niacin, Pyridoxine Hydrochloride (Vitamin B6), Riboflavin (Vitamin B2), Vitamin B12.

I’ll admit that removing the textured wheat protein was an impressive step in the right direction (and one that will make this “burger” easier to eat for millions), but the amount of oil is still an issue. Coconut and sunflower oil are at the top of the ingredient list. Especially for those people who tend to hyper absorb sterol, I am not 100% sure that the mega dose of linoleic acid and rancid omega-6 fats in the sunflower oil is any better than the saturated fat in a grass fed beef burger when it comes to cardiovascular health, although it likely comes down to genetics.

Although it is also made with vegetable oils, the Beyond Burger is probably a plant based burger that many will have an easier time with than the Impossible Burger (no soy, more natural ingredients like beets).

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Whole foods plant based?

The leaders of the plant based movement, the T. Colin Campbell’s and Caldwell B. Esselstyn’s of the world, are advocates of a whole foods, plant based diet, not a processed foods plant based diet.

The idea is that mother nature knows best, we do better the closer we get to consuming whole plant foods. While it is 100% Vegan, the Impossible Burger strays pretty far from this ideal. Creating genetically modified soy proteins in a test tube is a far cry from a macrobiotic plate. While some may do just fine with Impossible Burgers as a staple, I think it’s fair to assume that many individuals will be sensitive to soy leghemoglobin. After all, soy is one of the most notorious food allergens and humans have never consumed this particular soy preparation. Maybe it’s just me, but I’d much rather eat a plant based burger made to “bleed” with beets rather than genetically modified soy.

Closing Thoughts

In closing, I want to emphasize again that I admire the mission, as well as the ambition, of the Impossible Burger team. Kudos to them for trying to tackle such a big problem. And a big congratulations for removing the wheat from the burger.

However, in their quest to make a plant based burger to rival the traditional burger, they overlooked a basic principle of the plant based movement: that processed food is making people sick.

Consuming large amounts of factory meat has contributed to Americans to an epidemic of chronic disease in this country, but so has the use of pesticides like glyphosate on field after field of crops genetically modified to withstand these dangerous chemicals.

Many people develop autoimmune conditions when faced with the intestinal permeability that is a hallmark of eating wheat, GMO produce and processed foods.

So, yes, make a plant burger, just next time make it with actual plants.

Image credit – Eater San Francisco.

John O'Connor

John O'Connor is the founder of Gene Food, host of the Gene Food Podcast and a health coach trained at Duke's Integrative Medicine Program. Read his full bio here.

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