The “Impossible Burger” hit grocery shelves in 2017. It promised a safe alternative to beef; an environmentally conscious way to wean our meat-centric society off of actual animal flesh, to decrease the carbon footprint of our factory farms.

In the years since, this meatless, lab-grown, plant-based “beef” has exploded in popularity. Impossible Burgers (or meatless meat products like them) are now offered at over 7,000 different restaurants and chains throughout the US. The product was so hot at Burger King it actually resulted in a national Impossible Burger shortage earlier this year.

Now, though, people are pumping the brakes. Research, done by the very company that created this stuff, has raised some potential red flags about this red meat alternative, suggesting that it might cause kidney disease, anemia and a litany of other health issues.

Let’s back up a second, though. Because we aren’t talking about veggie burgers or vegan burgers, which are made with actual legumes, vegetables and other common non-meat ingredients. We’re talking about beef grown in a lab using chemical substances to recreate the taste and texture of actual beef. It looks pink and even bleeds like the real deal — but it isn't. It's "plant-based."

When companies like Impossible Foods (who make the Impossible Burger) say that phrase, “plant-based,” they mean that their scientists selected specific proteins and nutrients at a molecular level from plants, that they then fused together in a petri dish to make a synthetic beef patty. One of those proteins is called soy leghemoglobin (SLH), and it has raised some serious questions from both the FDA and concerned nutritionists about the safety of these plant-based burgers.

SLH is the cornerstone chemical of the Impossible Burger (and other similar products). It’s what gives this synthetic beef its meaty flavor and creates that lovely “bleeding” effect that people enjoy so much.

But SLH is a shady substance — one that the FDA has expressed concerns over.

“Although proteins are a part of the human food supply, not all proteins are safe,” the FDA stated in their response to the Impossible Burger’s first application in 2015. “FDA believes that the arguments presented, individually and collectively, do not establish the safety of SLH for consumption, nor do they point to a general recognition of safety.”

That first application for “GRAS” status (Generally Recognized as Safe) was rejected — the FDA refused to agree that the SLH was safe to consume.

So, in 2017 Impossible Foods tried again. They resubmitted their application to get the Impossible Burger recognized as GRAS. And this time they included a short 28-day study done on a handful of mice, testing the health effects of long-term consumption of their meatless meat.

The results do not inspire confidence.

Even though Impossible Foods deigned the study to be statistically weak in their favor (most studies run for at least 90-days, not just 28, and include hundreds of sample subjects, not just 20) the dark truth started bleeding through their science. There was a clear list of adverse health effects that the sample mice began exhibiting.  

For example: The mice showed “unexplained transient decreases in body weight,” despite consuming more food; their red blood cell count decreased (a symptom of anemia and/or bone marrow damage); their blood clotting abilities decreased; their blood showed low levels of alkaline phosphatase (a symptom of malnutrition and/or celiac disease); their blood showed an increase in albumin (associated with acute infections) and increased potassium values (associated with kidney diseases); their blood glucose was diminished (low blood sugar); and, their blood globulin values were up (common in inflammatory diseases and cancer).

After just 28 days of regular consumption, these mice were falling ill and looking malnourished. Which is probably why Impossible Foods decided to cut the study length down to a third of the standard duration.

Still, the FDA dismissed all of this questionable evidence and granted the Impossible burger its GRAS status on its second application. In 2017 they issued a “no questions” letter to Impossible Foods.

Which, it’s worth noting, doesn’t mean that the FDA considers the Impossible Burger safe. A “no questions letter” simply acknowledges that the company has stated their product is safe and reminds the company that they, not the FDA, are responsible for putting safe food products on the shelves. Essentially, it’s a liability waiver from the FDA, resigning all responsibility for the product over to the company.

And now, these burgers are everywhere. They’re offered at Bareburger in NYC; they’re at Umami Burger in California; at Burger King's across the country and White Castle’s throughout the East Coast. Hell, they even made it into a recent South Park episode.

The goal behind meatless meat is a noble one: Make meat in a lab, so we don’t have to raise it on a farm, so that we’re mitigating our species’ environmental impact. But the reality of it is not so straightforward. We don’t know what these burgers will do to people who eat them regularly on a long-term basis. 

So, for now, if you want to make your diet more carbon conscious, it might be safer to just stick with a good old-fashioned veggie burger. Or, call me crazy, an actual salad… 

There are a lot of other ways to not eat meat, without eating this stuff.