FDA Approval of Chicken in Cell Culture: The Rise of Fresh Meat Without the Animal?

On November 14 of this year, the FDA cleared the way for Upside Foods to sell its cell culture-based chicken products in the United States. This is the first product of its kind to be cleared for commercial sale in the Americas, with only Singapore having previously cleared a similar product for sale, in December of 2020. This latest product comes courtesy of another California start-up called Eat Just.

Since the initial approval in Singapore, Eat Just has set out to set up a 2,800 square meter (~30,000 sq ft) manufacturing facility in Singapore that is expected to start producing thousands of kilograms of slaughter-free meat starting Q1 2023. This it would make it the top runner in the cultured meat industry, which so far has seen dozens of startups, but precious few actual products for sale.

With Eat Just CEO Josh Tetrick predicting price equality between their cultured meat and animal meat by 2030, could the FDA approval herald the dawn of slaughterless meat? Of course, there are still hurdles, but as we’ll see, the idea isn’t as far-fetched as one might think.

A long story

The history of cell cultures dates back to the 19th century, when it was discovered through experimentation that tissues and entire organs could be kept alive, even after being separated from the body. Subsequent research during the early 20th century increased our understanding of tissue and cell cultures, which during the 1940s and 1950s led to such medical advances as the cultivation of viruses in cell cultures to produce vaccines.

The injectable polio vaccine, developed by Jonas Salk, was among the first mass-produced products using such cell cultures. In addition to vaccine development, the ability to not only isolate cells but also keep them alive for long periods of time led to countless medical and scientific breakthroughs over the following decades. Some of these cell cultures used in laboratory settings are also immortal, either because of their starting point as a (human) cancer cell, because they are stem cells, or because of the immortalization treatment. Having immortalized cell lines allows for long-term studies of a well-documented cell type.

Perhaps unsurprisingly, such cell cultures are involved in the early stage of setting up a cultured meat production line. The following steps are detailed in the FDA memorandum regarding the approval of the Upside Food product:

  1. cell isolation
  2. Establishment of cell lines
  3. Establishment of Master Cell Banks (MCB)
  4. Proliferation stage
  5. stage of differentiation
  6. Collection of cellular material

None of these steps are necessarily new or uncommon within a laboratory setting. Initial seed cell isolation involves extracting these from a chicken. These must then be characterized and checked for any pathogens. The resulting cells are then immortalized using telomerase reverse transcriptase (TERT) gene therapy as needed, to establish master cell lines. These cell lines are immortal and can therefore be used for the further life of the production line.

During the proliferation phase, some of the cells from the cell banks are introduced into a bioreactor, where the cells are encouraged to multiply in suspension culture, while immersed in all the nutrients they need and at a constant pH and temperature. Once enough cellular material has formed, they are moved on to the next stage, which is where these cells will differentiate into muscle (myocytes) and connective tissue (fibrocytes). Both will adhere to the walls of the bioreactor and to each other, forming a multicellular tissue.

After this step, the contents of this final bioreactor can be extracted and is essentially ready for preparation and consumption.

Growing pains

As they say, if something were easy, someone else would have already done it a long time ago. In the case of cultured meat, most of the challenges lie in moving from a laboratory environment involving small batches of cell cultures to huge bioreactors capable of producing thousands and thousands of kilograms of product.

Getting these bioreactors to maintain cell content as nutrients are added and waste products removed is one thing, but another is the entire supply chain surrounding the operation. Right now, there is no massive industry that can supply these nutrients on a scale needed to replace a significant portion of today’s meat consumption. All of these supply lines will need to grow along with this nascent cultured meat industry.

A major cost and bottleneck here is the growth medium, especially the growth factors that cells need to multiply. Common sources for laboratories include fetal bovine serum (FBS) along with serum from other animals. Slaughterhouses are generally the primary source of blood from which serum is extracted. Finding replacements for this whey and their growth factors is an ongoing topic and obviously very relevant to cultured meat.

An alternative is human blood, called hPL (human platelet lysate). This is a replacement for FBS that is created from previously extracted platelets that have expired. Since these have been extracted from blood donated for transfusion purposes, hPL provides an alternative cruelty-free source. The main hurdles here are that the quantity is only sufficient for small-scale laboratory settings, and there are issues with cost and consistency between batches.

An ideal alternative for FBS, hPL and the like would be a completely artificial and synthesized alternative, as this would alleviate any food safety and ethical concerns. Unfortunately, as also covered in a 2021 review by Chelladurai et al. in Eliyon, there is still no clear alternative. This reinforces the idea that finding a whey-free substitute for cultured meat is likely to be one of the biggest hurdles in the near future, both in terms of its ethical image and making sense of its ultimate price.

Still worth it

Even with the obvious challenges of scaling up cultured meat products, there’s no denying that its potential positive impacts could be enormous. In a 2017 report (PDF) from the Food and Agriculture Organization of the United Nations (FAO), it is noted that agriculture is responsible for approximately 70% of global freshwater use, a significant amount of which is destined to feed livestock: 15 tons of water per kilogram of meat – and other animals destined for meat production.

(Credit: FAO)

When there are about three chickens on this Earth for every single human being (~24 billion chickens), with similar numbers for cattle and sheep, it’s not hard to see how the meat industry has some impact on the environment and, moreover, consequence on the climate. If we succeed in eliminating the need to raise animals for slaughter in the coming decades, we will regain many thousands of square kilometers of pasture and farmland, with corresponding reductions in greenhouse gases.

By moving the entire meat industry to sterile, fully controlled factories, this would also essentially eliminate contamination problems, such as Salmonella in chicken meat. It would alleviate the need for antibiotics and generally result in a safer, more predictable and consistent product, while still being the same meat. Just without the part where an animal is raised from a chick, calf or piglet before its disappearance in a slaughterhouse.

Opinions remain divided

It should not be repeated that not everyone agrees on the need for cultured meat, with plant-based protein alternatives generally being brought forward as the obvious alternative to meat. Even though I’ve been a vegetarian for a long time, the idea that not everyone will want to give up eating meat seems inevitable. However, since the main problems with the meat industry are the aforementioned environmental impact, cultured meat would seem to be a more than acceptable solution.

Assuming we can make cultured meat work by 2030, we could see a corresponding decline in livestock feed needs, relieving the pressure to produce enough food for an ever-growing human population, while still allowing those who cannot their meat habit to dig into a fresh piece of genuine chicken or beef. All thanks to some scientists who tinkered with some animal tissue over a hundred years ago.

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