Meatless Meat Is a Mixed Bag

Impossible Foods released their new plant-based chicken nuggets on Tuesday, and some corners of the internet are as excited as ever about this latest addition to the fast-food chicken lineup. But with the debut of these vegan soy protein bites, an old question is dragged out of the freezer once again: Which is healthier, meat or its plant-based alternatives?

The answer is more complex than it seems. Only limited research so far has examined the nutritional profiles head to head, and even fewer studies have looked at health effects in humans. In addition, imitation chicken, as opposed to beef, poses an entirely new obstacle for health professionals and their patients. Experts have noted that we need more rigorous, long-term studies — especially in an era in which plant-based meat alternatives mimic the taste of meat better than ever.

Amidst the nutritional ambiguity, the argument for replacing meat with plant-based foods can’t be separated from its context: the rest of one’s diet, and the significant environmental and public health implications. For now, nutrition experts say that plant-based meat alternatives don’t offer many nutritional advantages to their counterparts. At best, they serve as a bridge toward consuming fewer animal products.

Individual Nutrition and Health

A handful of studies have compared a variety of meats with plant-based meat alternatives, with mixed results. Experts cited one 2020 randomized trial, led by Christopher Gardner, PhD, of Stanford University’s Prevention Research Center, as one of the only studies to examine the overall health effects in humans. Of note, it was funded by a grant from Beyond Foods, another distributor of plant-based meat alternatives.

Adult participants ate either “real” meats or their plant-based alternatives for 8 weeks, and then swapped for another 8 weeks. Researchers looked at outcomes such as concentration of TMAO (trimethylamine-N-oxide), a gut-flora metabolite that indicates risk for cardiovascular disease, LDL cholesterol, and body weight. All three improved with the plant-based alternative foods.

“I think those results are quite encouraging,” said Frank Hu, MD, PhD, of Harvard Medical School and Brigham and Women’s Hospital in Boston, who is also the director of the Boston Nutrition Obesity Research Center Epidemiology and Genetics Core. “But, of course, these findings need to be replicated in much larger, longer-term studies.”

Another study examined the nutrient composition in beef and beef-alternative products from 37 top brands, including Impossible and Beyond. It found that, overall, the beef alternative products had more fiber, folate, and manganese, and were sometimes, but not always, lower in saturated fats. They were also generally lower in protein, high in sodium, and low in vitamin B12, which can only be found in animal products unless fortified.

“It surprised me that some of them were high in saturated fat. It seemed like it would have been great if the manufacturers could have formulated them a little differently,” said study author Lisa Harnack, DrPH, a registered dietitian and director of the Nutrition Coordinating Center at the University of Minnesota’s School of Public Health.

Impossible’s burgers, she noted, were the exception: “They really clearly made an effort to make the nutrients pretty close to ground beef.”

One study from Australia looked at the nutritional profiles of 137 plant-based substitutes available there (including Beyond) and found similar results: plant-based alternatives were higher in carbs, fiber, and sugar, but lower in calories. Generally, however, plant-based chicken was highest in fat among all of the plant-based options.

Harnack said that plant-based alternatives tend to vary so widely that “you kind of have to read the product labels to find one that aligns with your nutritional needs.” Someone with high blood pressure, for example, should seek out plant alternatives without high sodium. Some products are fortified to meet daily nutritional requirements, while others aren’t. When fielding questions about plant-based alternatives versus the real thing, “you’d have to think about what the nutritional concerns of that person are and give advice based on that, because there isn’t a pat answer,” she said.

The Chicken Question

Imitation chicken that actually tastes like chicken is newer to the plant-based alternative game. But in terms of health, plant-based chicken nuggets aren’t necessarily a step forward, said Kevin Klatt, PhD, RD, of Baylor College of Medicine in Houston. “These processed vegan foods are fine, and they have their place, but I’m not ever going to be recommending a really salty chicken nugget alternative in the same way that I’m not really going to be recommending an actual animal-based version of it,” he said.

In fact, the nutrition panels on a four-piece order of nuggets from McDonald’s and four of Impossible’s plant-based chicken nuggets look fairly similar. The vegan nuggets contain slightly more protein, have the same amount of fat (including saturated fats), and almost the same amount of sodium. Impossible’s nuggets are even fortified with B12.

There are a few differences, however. Impossible’s nuggets contain no cholesterol, compared with McDonald’s 25 mg, but they add some calories and eight more grams of carbohydrates.

But it’s not just nutrient comparisons: experts have said it’s important to weigh the benefits of replacing chicken in a diet, as opposed to replacing red meat. Red meat, consumed widely in Western diets, is linked to a host of negative long-term health outcomes: increased risk for cardiovascular disease, obesity, type 2 diabetes, and even some cancers. Chicken, on the other hand, delivers protein without a strong association with chronic disease. “Poultry tends to be the thing that gets the biggest free pass as far as animal proteins go,” said Klatt.

“When it comes to chicken alternatives, it’s a little more complex, because poultry has a better fatty acid profile to begin with,” said Walter Willett, MD, DrPH, of Harvard T.H. Chan School of Public Health. “Long-term epidemiologic studies have poultry as a better alternative to red meat, so we’re starting with something that’s not as bad as red meat.” However, he called it an “open question,” reiterating that more data are needed.

Better Than Meat Imitators

Nutrition experts stressed that though plant-based alternatives to meat might reduce the health burden of a diet high in animal products to some extent, a better choice would be to eat other protein sources all together.

“I frankly tell people that if you’re looking to transition from eating more meat for environmental sustainability reasons or the potential perceived health benefits of it … ultimately, the foods that you will want to focus on are where we have more data, like edamame or tofu or tempeh, these other whole-soy products that have more fiber,” said Klatt.

“There has been little to no progress getting Americans to eat less beef and more beans in the past few decades. The introduction of alt-meat products in the past five years has started to change this … largely because the new products are being designed for meat eaters and not for vegetarians. They are being developed to look, smell, and taste like animal meat,” Gardner wrote in an email to MedPage Today.

Willett likened plant-based meat alternatives to a bridge of sorts, for those who aren’t ready to swap out burgers for lentil stews just yet. “These new products would be in between that, not as good as the natural, whole-food kind of product, but if you’re not ready to take that step, I think it is often a step in the right direction,” he said. “I think of them as like a nicotine patch for smokers — a whole lot better than continuing to do the real thing.”

“A switch to a processed vegan alternative is probably just a neutral health impact,” countered Klatt. “I don’t think there would be a major health win, per se.”

It’s also important to consider the context in which a swap for meat is happening. “Our overall diet in which we consume individual foods is far more important in determining what the health outcomes are and determining whether we end up with certain nutrient deficiencies or not,” said Stephan van Vliet, PhD, of Duke Molecular Physiology Institute and lead author of a study published in Scientific Reports that analyzed the metabolites of grass-fed ground beef and its plant-based beef alternative.

van Vliet emphasized that many of the compounds in plant-based proteins are quite different from those in meats, like the antioxidants anserine and creatinine. “If you eat an omnivorous diet and you replace red meat once or twice per week with tofu, then obviously something like that will probably have no negative effects on your health … we can’t really say, but it’s such a minor substitution,” he noted.

Hu pointed out that plant-based meat alternatives are often consumed in a fast-food context; for example, “an Impossible burger with soda or sugar-sweetened beverages, big-sized French fries … these plant-based meat alternatives can be an option to cut back on red and processed meat, but you should also pay attention to your overall dietary pattern,” he said.

Other Considerations

Beyond individual health, there’s the larger implications to consider: meat’s impact on the environment, its role in climate change, animal welfare, and the role of livestock in increasing antibiotic resistance and spreading disease.

Beyond Meat’s analysis, which commissioned the Center for Sustainable Systems at the University of Michigan to assess their environmental impact, found that their burger cuts greenhouse gas emissions by 90% and uses 99% less water and 93% less land compared with traditional U.S. beef.

In a commentary for JAMA, Hu and colleagues noted that Beyond and other options “are likely to have less environmental effects than industrial beef production based on the metrics analyzed. However, the robustness of this conclusion warrants further studies.”

Gardner also pointed to animal rights: “The alt-meats are obviously better for animals … because it means fewer animals would be raised and slaughtered for meat consumption if people chose alt-meat over animal meat.”

As for antibiotic resistance due to widespread use in livestock, eating fewer animal products could help alleviate this. “Looking to eliminate antibiotics in animal uses is very important, because we’re getting close to running out of antibiotics,” said Willett. “Some people will die because of this antibiotic use.” Public health risks of animal-to-human transmission of antibiotic-resistant pathogens is also a major concern.

The bottom line: switching to plant-based meat alternatives may or may not confer some health benefits; it all depends on their composition, individual health needs, and one’s overall diet. More than that, they’re part of a bigger food system, the realities of which are often what prompt people to sub in plant-based alternatives in the first place. These can’t be divorced from the health concerns, experts noted.

“A lot of people want to consume those products for both human health and for the environment, but I think these products have to deliver on both fronts,” said Hu. “Otherwise, I think the trend may not be able to sustain.”