Burger King is now serving up its brand of the Impossible Burger at all 7,200 locations across the nation. The Impossible Whopper is a flame-grilled, plant-based patty that so closely mimics meat it “bleeds.”
We spoke with Bridget Shea, RD, registered dietitian, to learn about the nutritional aspects of this vegetarian innovation.
What make the meat taste possible?
Bridget Shea: The Impossible “meat” gets most of its taste and appearance from the protein soy leghemoglobin, a plant globin protein similar to the hemoglobin in human blood.
The source of the soy leghemoglobin in the Impossible patty is not soy plants. It is genetically modified yeast that makes soy leghemoglobin as a byproduct of fermentation. Genes from the soy plant are introduced into yeast cells so that they are able to carry out the process of creating the soy leghemoglobin. Then, the yeast is separated from the leghemoglobin and it can be added to the Impossible “meat” to give it the taste and appearance of beef.
What are the health concerns?
The main concern is that we don’t know the long-term impacts of ingestion of soy leghemoglobins on human health. There is also concern regarding the allergic properties because soy is one of the eight most common allergens. The FDA granted Leghemoglobin as GRAS (Generally Recognized as Safe), but there is still a lot that isn’t known.
How does the Impossible Burger stack up nutritionally to a beef burger?
Per the Impossible Foods website, the Impossible 4 oz. patty has 240 calories, 14 grams of fat, and 8 grams of saturated fat. It has 19 grams of protein, 3 grams of fiber and 370 mg of sodium. This is the patty alone and doesn’t include toppings, buns, sauces and other foods served alongside it. A 4-ounce 80/20 beef patty has 280 calories, 22 g of fat and 9 g of saturated fat. It has 19 g of protein and 75 mg of sodium. A regular beef patty contains no carbohydrate so does not have any fiber.
Should we be concerned about carcinogens when flame-grilling either beef or plant-based burgers?
With beef, yes. When the heat comes into contact with the meat, there is a chemical reaction among certain amino acids, sugars and creatine. This reaction forms chemicals called heterocyclic amines (HCAs) — known carcinogens. HCAs form when we pan-fry meats. When we cook meats over open flames or smoke it, polycyclic aromatic hydrocarbons (PAHs) form. These are also carcinogens.
It is important to avoid eating charred meats and limiting intake of processed meats. Eating meat as part of a diet rich in antioxidants and phytonutrients from plants is crucial to reducing risk of developing cancer.
We know less about the health impacts of charring plant-based foods. There is some evidence that the browning of some plant-based foods leads to the formation of chemicals that may pose health risks to humans. We need more research.
Could the Impossible Whopper be a “gateway” food to turn people onto plant-based alternatives?
I think it is great that vegetarian and plant-based alternatives are becoming more mainstream and widely available. The public often views adopting a plant-based diet as needing to become a vegetarian or vegan. Really, it means that plants are the foundation of the diet, with less emphasis on foods sourced from animals. Think fruits, vegetables, nuts, seeds, legumes and grains.
When adapting a plant-based diet or trying new foods, educate yourself on new foods so that you understand how they can fit into a healthy and balanced diet. If you have questions seek out advice from a registered dietitian!
What are your thoughts about cutting back on, or even eliminating, red meat from your diet?
Research associates red meat with many chronic health conditions, including certain cancers, diabetes and heart disease. Research also shows that diets lower in red and processed meats tend to be associated with more positive health outcomes.
For a healthy diet, limit or moderate red meat and use substitutes for lean animal protein sources. Think fish, lean chicken, Greek yogurt, beans/legumes, whole soy and nuts/seeds. I always recommend that we use meat more like a condiment or side dish, rather than the main part of the meal, so that it isn’t the main source of calories or macronutrients. That way, we can enjoy the taste of meat but get more of the nutrients we need from plant-based sources.