The “Clean Meat” Industry Has a Dirty Little Secret

Startups aim to grow meat from animal cells, but for now they use ingredients you may not want to eat. Illustration by Alex Gamsu Jenkins

Manufactured meat may be safer and better — but first, producers need to get rid of the icky ingredients.

For nearly twenty years, the idea of growing edible meat directly from animal cells has enticed animal-welfare advocates, health-conscious foodies, and people disgusted by the way meat is produced today. These days, that idea is attracting investors and entrepreneurs, too.

This isn’t your (vegan) father’s Tofurky. More than a dozen companies worldwide are working on slaughter-free meatballs, tenders, or simple ground beef, chicken, fish, or pork made by growing muscle tissue in a cell culture. Big Ag powerhouses like Cargill and Tyson Foods have put money behind it. And at least one company, Just Foods, says it will have a product, likely bird-based, ready for market by the end of the year — although the company says whether it can sell the faux fowl will be up to regulators.

Boosters like the nonprofit Good Food Institute, a spinoff of the animal-rights group Mercy for Animals, are heralding a new era of “clean meat.” They say this technology will end the filth, danger, and disease that come with raising and processing animals to eat. It will keep drug residues off our dinner plates and thwart foodborne illness and antibiotic resistance.

“Clean meat is the clean energy of food,” Good Food spokesperson Matt Ball says in an email. “Clean meat will be vastly better in many, many ways, including for public health.”

But the industry has yet to prove that it can be so clean. Most of these companies are startups in prototype phase, still reliant on unappetizing additives — which they insist won’t be necessary once they graduate to commercial scale. Meanwhile, experts worry that as the volume increases, so will the risk of contamination. The meat makers say these concerns are easy to address, and promise to soon deliver savory goodness far safer than anything from a feedlot.

The truth is, there’s a chasm between the current state of clean meat and an industrial-scale food source that lives up to the name — and no one knows yet how to get to the other side.

Regulators take notice

The dirty side of clean meat took center-stage in late October at a joint hearing of the United States Department of Agriculture and the Food and Drug Administration. While the meeting was convened to discuss labeling — just what to call this new type of foodstuff — the details of production were also picked over by the FDA’s science board, a group of experts in food safety, medicine, epidemiology, drugs, and veterinary medicine.

The evidence they reviewed suggests that at this point, the meat-making entrepreneurs haven’t quite yet hit the clean meat threshold. Many companies use antibiotics, hormones, even blood products taken from fetal calves, at least during the first steps of the process, to get initial batches of cells to transition from life inside an animal to life inside a vial or dish. Industry surveys discussed by the board suggest that so far, most production systems also require artificial or animal-based additives to keep the cells growing.

Some board members also noted that it’s not yet clear how muscle cells will react when they’re grown in huge bioreactors. Unhappy cells may pump out stress-related compounds that humans may not want to eat. And without perfect sterility — or doses of antimicrobials — those massive vats, warmed and filled with nutritious broth to encourage growth, might get invaded by bacteria and fungi.

While the risks of producing conventional meat might diminish, growing muscle in vats may bring new ones.

These questions need to be answered with independent studies and cold, hard, public data, said food safety scientist Barbara Kowalcyk of Ohio State University, a member of the FDA’s science board.

“I don’t think we actually know enough about what the potential hazards are, and that’s what concerns me,” she said.

“Some of the companies are talking about having product this year, and have not sent a single sample out to any independent review,” charged Michael Hanson of Consumers Union.

The cultured-meat crowd, who turned out in force for the hearing, countered that the pharmaceutical industry routinely grows cells in culture to make vaccines and biologic medicines. Their methods aren’t new, and they aren’t inherently risky, they said. Inspections will catch any problems before products leave the building, let alone hit store shelves.

“These hazards are well understood, and there are well established methods for controlling them,” Eric Schulze of San Francisco-based Memphis Meats said at the hearing.

Besides, the producers pointed out, conventional meat is frequently contaminated with anything from the potentially deadly bacteria E. coli O157:H7 to low doses of antibiotics such as tetracycline, and hundreds of people die every year in the U.S. from illnesses caused by tainted meat and poultry. Manufactured meat offers the potential of greater consistency and tighter control over such risks, they said.

“I don’t think you’re going to have a greater risk than you have with, for example, the risk of E. coli in hamburger meat, or the current risk of salmonella in chicken,” said former FDA reviewer and pharmaceutical industry consultant Rebecca Sheets, who has analyzed contamination episodes in vaccine production.

The problem is that biology is never perfectly clean or perfectly predictable. As Sheets pointed out, while the familiar risks might diminish, there may also be new ones. We just can’t predict them, because nobody has ever grown muscle cells in 25,000-liter vats.

The cultured-meat recipe

To make a cultured burger, first you biopsy a cow, pig, or other meat animal. This tissue sample will likely need dosing with antibiotics to kill off what was growing in or on the animal, plus enzymes to liberate the muscle and/or fat cells so they can be separated from other types of cells.

Next, select out the cells capable of dividing and maturing into muscle or fat. You might genetically engineer them or otherwise manipulate them to become immortal, creating a renewable seed stock. At this point, if you’ve done the job right, there’s no further need for antimicrobials, the meat makers say.

Now put some of these cells into cell culture with a mix of growth factors, hormones, and nutrients to help them divide and mature into muscle. Many manufacturers use fetal bovine serum (FBS), which is collected at slaughterhouses from the blood of fetal calves.

Some manufactured-meat proponents argue that these new foods should be assumed safe until proven otherwise.

No company can afford to scale up production relying on this expensive animal-based elixir, so developing affordable plant-based FBS replacements is an area of intensive R&D. What’s in those formulas is usually kept secret — but they typically include hormones and cytokines, another type of signaling molecule.

The cells may also need scaffolding to attach to — another area of competition and rapid change. It could be collagen or gelatin derived from animals or generated by genetically-engineered microbes.

The big picture is that what’s in your vat at this point isn’t just animal cells. It’s a mix of natural, artificial, and plant- and animal-based materials. If it all works properly, and you keep microbial invaders out, you wind up with something similar to ground beef, chicken, fish, or pork.

New Age Meats cofounder Brian Spears, who offered a taste of the company’s pork products to the media in September, says the company still uses FBS for its cell cultures for now. But his team is working on a way to dispense with it by getting cells to grow by stressing them with changes in temperature or pH.

“We are a young company, we are in research,” he says. “One question that people have is, ‘We have to know what your processes are.’ My response is: ‘We’re developing those processes.’”

Developing is the key word. Any process a fledgling manufactured-meat company starts out with will be revised repeatedly as it scales up. These companies are only beginning to produce burger-sized amounts of meat. To replace just 10 percent of U.S. beef production, they’ll need to churn out almost 1.5 million tons a year.

So even though the industry can get started with protocols developed for pharmaceuticals, it will need to blast past them to produce food in commercial volumes.

That feeds into critics’ top worry: invasion by pathogens like listeria or mycoplasma.

“Anybody who has worked with cell culture knows that even in a very sterile environment, cross-contamination issues can be a real problem,” said Rhonda Miller, a meat scientist at Texas A&M. “As we upscale this technology, there are a lot of things we don’t know about how to control” that problem.

Cultured-meat makers respond that it’s not really mysterious.

“The concerns [expressed at the hearing] were valid — there are things that do need to be checked for,” such as microbial contaminants, says Mike Selden, CEO of Finless Foods, an early-stage cell-based fish company. “But none of it seems disqualifying to me.” There are well-known ways to test for every one of these contaminants, he says.

For that reason, Schulze and others argue that these new foods should be regulated like any other food — that is, assumed safe until proven otherwise, and allowed to go to market with only in-house safety checks.

Lab to table?

Typically, governments spend months or years developing regulations, so likely we won’t know for a long time exactly what rules will govern this new sector. But even if regulators take a light hand, and even if producers perfect their techniques and eliminate some of the less savory ingredients, these fledgling companies face another hurdle: Public opinion.

The shadow of genetically modified food hangs over meat made in vats. More than a third of U.S. consumers think GMOs are unhealthy, in part because of the widespread impression that the technology was rolled out without their knowledge, understanding, or approval. Secretive, high-tech meat producers could wind up in a similar backlash if consumers feel misled by the promises of clean meat.

Some producers are backing away from the “clean meat” label, calling their offerings “cell-based meat” instead.

The mass revulsion when people learned in 2012 that hamburgers often contain a byproduct called lean finely textured beef — what was dubbed pink slime — is another example. Food buyers who feel they’ve been tricked into eating mystery meat get upset.

Some producers are already backing away from the “clean meat” label, preferring to call their offerings “cell-based meat” instead. Finless Foods’ Selden says that, while his company keeps trade secrets for now, if customers want to know every detail of the production process, he’ll make it all public. He plans to move slowly, refusing to say when the company will have products on the shelves.

“We genuinely want to prove this stuff is safe, and if that takes a while that’s okay by us,” he says. “We need consumers to trust us.”

For Selden, Spears, and their competitors, that could be the toughest challenge of all, one they can’t solve through better engineering or a new and improved cell-culture protocol. For the big promises of clean meat to come to fruition, meat eaters will need to be confident that these products are just as good and safe as what they’ve been eating all along. The formula to produce that confidence is still an unknown recipe.

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