Impossible Burgers, plant-based burgers that many consumers say taste remarkably like beef-based hamburgers, are now available in the Burger King fast-food joints in Liberty and Monticello, and many other restaurants around the county. Soon they are expected to appear in grocery stores. One Impossible Burger purchased in the Liberty Burger King in recent days did, in fact, taste very much like that chain’s signature Whopper, although the Impossible cost a couple of dollars more than the Whopper.

The questions emerging now are these: are Impossible Burgers better for the environment than beef burgers, and what about the impact on human health? Some groups are reflexively opposed to Impossible Burgers because they are made with genetically modified (GMO) soybeans and plants. The ingredient that provides the highly praised, true meat flavor is called soy leghemoglobin.

What’s that? From the website of Impossible Foods, the company that produces the plant-based burgers, “Soy leghemoglobin is short for legume hemoglobin—the hemoglobin found in soy, a leguminous plant. Leghemoglobin is a protein found in plants that carries heme, an iron-containing molecule that is essential for life. Heme is found in every living being—both plants and animals. (Heme in animals is carried by “hemoglobin” and “myoglobin,” among other proteins.)

“Although heme has been consumed every day for hundreds of thousands of years, Impossible Foods discovered that it’s what makes meat taste like meat. We make the Impossible Burger using heme from soy plants—identical to the heme from animals—which is what gives it its uniquely meaty flavor…

“Yes. We genetically engineer yeast to make ‘soy leghemoglobin’ or “heme”—one of the key ingredients in the Impossible Burger. This process allows us to make heme at scale with the lowest achievable environmental impact.

“We make heme using a yeast engineered with the gene for soy leghemoglobin. First, we grow yeast via fermentation. Then, we isolate the soy leghemoglobin (containing heme) from the yeast, and add it to the Impossible Burger, where it combines with other micronutrients to create delicious, meaty flavor.”

The Center for Food Safety (CFS) say this “heme” has not been sufficiently tested. “This is the first time that people have consumed this product. The U.S. Food and Drug Administration (FDA) is supposed to require testing in this situation to make sure that this novel protein does not cause allergic reactions in people. Unfortunately, instead of requiring Impossible Foods to file a new Food Additive Petition, FDA allowed the company to use a weak regulatory process called “Generally Recognized as Safe” (GRAS), where the company does its own research and chooses its own reviewers to self-certify that its product is safe for human consumption.” CFS has filed a lawsuit against the FDA.

The second issue CFS and other groups have against Impossible Burger is that the soy protein concentrate used to create the bulk of the burger itself is made from GMO soybeans. “Impossible Foods does not describe how it processes the soy, but alcohol is the most common solvent used to process soy protein concentrate, as it produces products with a neutral taste. But the beneficial isoflavones in soy are removed by this method,” writes CFS.

Further there is the fact that over 80% of GMO crops have been engineered to withstand being sprayed with glyphosates. “Unfortunately, GMO soy is also sprayed with large amounts of the herbicide glyphosate, a product shown to cause cancer in people exposed during its application. GMO soy has been found to use significantly more herbicides than conventional soy or organic soy. At a time when juries are awarding billions of dollars in damages to those affected by exposure to glyphosate, it is startling that Impossible Foods would double down on the GMO soy that is inextricably linked to this toxic herbicide.”

Impossible Foods is not the only player in the plant-based burger space. There is also the company Beyond Meat. Most analysts agree that both burgers are better for the planet in that less water, space and resources are used to make them. But the impacts on human health are not as clear, with one critic pointing out that both products can be classified as highly-processed food. And more than one foodie pointed out that a much healthier veggie-burger can be made by almost anyone at home with plant ingredients carried in virtually every grocery store.