Lab-grown meat isn’t made of cancerous cells

On 23 June 2023, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) granted its first-ever approval for producing and selling cell-cultivated meat—also known as lab-grown meat—in the U.S. The two companies that received the green light, UPSIDE Foods and GOOD Meat, had previously received safety clearance from the U.S. Food and Drug Administration (FDA), which concluded that their chicken products meet the agency’s requirements and are safe to consume.

The U.S. thus became the second country in the world to authorize the production of cell-cultivated meat only after Singapore, where cultivated chicken meat was approved in December 2020. The USDA and the FDA explained in a joint statement that both agencies will share responsibility for overseeing the production of cell-cultured meat to ensure that these products are safe and accurately labeled.

Following U.S. regulators’ approval, a video originally posted on TikTok claiming that cultivated meat is produced using animal “cancerous and pre-cancerous cells” went viral on Facebook.

The person speaking in the video is Kashif Khan, the CEO and founder of The DNA Company. Khan doesn’t appear to hold any qualification in biology or medicine, but nevertheless offers advice on preventing and reversing chronic diseases through functional medicine, a practice that lacks scientific support.

The claim stemmed from the idea that a procedure known as immortalization used for producing cultivated meat turns the cells cancerous. However, this idea is incorrect. As we will show below, immortalized doesn’t equal cancerous, and there is currently no evidence indicating that using this procedure makes cultivated meat unsafe to consume.

How is cell-cultivated meat produced?

Broadly, the process consists of collecting cells from a live animal’s muscle or skin in a biopsy and growing them in a controlled, sterile environment. First, the cells from the biopsy are screened, selected, and grown at a small scale to create a cell “bank” that can be stored for later use.

Then, some of these cells are put in a nutrient-rich solution that allows them to divide until they reach the large number required for industrial production. This phase is known as proliferation.

After that, the cells go through a process of differentiation in which a different set of nutrients helps them develop into the various cell types that make up meat, including muscle, fat, and connective tissue cells. In addition, the manufacturers use different biomaterials that serve as scaffolds for the cells to help them organize into a three-dimensional structure that resembles meat. Finally, the cells are harvested to undergo standard food processing.

Immortalized doesn’t mean cancerous

One critical limitation when producing cultivated meat is that the cells collected in the biopsy can only divide a limited number of times until they reach senescence. At that point, they stop dividing, greatly restricting the number of cells that can grow out of a single batch of cells.

To overcome this limitation and upscale production, manufacturers use a procedure called immortalization, which consists of modifying the cells genetically so they divide indefinitely. This procedure has been used for decades in biomedical research for multiple purposes, including studies on gene and protein function, vaccine production, and drug testing.

The video claimed that immortalization turns the cells into “cancerous and pre-cancerous”. This would mean that these cells have the capacity to grow without control and invade nearby tissues (cancerous) or that they have abnormal changes that make them more likely to develop into cancer cells (pre-cancerous). However, this claim is incorrect.

While cancer cells can divide indefinitely, this is only one of the various characteristics that make them cancerous. To be considered cancerous, the cells must also have the capacity to create new blood vessels and invade neighboring tissues, and show unpredictable, uncontrollable behavior^[1].

Joe Regenstein, a professor emeritus of food science at Cornell University, told AFP that this isn’t how immortalized cells behave. “Immortalized cells are essentially the exact opposite of cancer cells” because “They are highly controlled and repeatable”, said Regenstein.

While turning the cells into a tumor is one way of immortalizing them, there are other methods that make the cells divide indefinitely but still retain the features and behavior of the original cells they come from. Cells immortalized in this way aren’t cancerous.

One of these methods is introducing the gene telomerase reverse transcriptase in the cells, which counteracts the shortening of chromosomes that leads to aging. This is the method used by Upside Foods, according to an FDA memorandum released in 2022. Another company, GOOD Meat, used a different method, which consists of culturing the cells and selecting those with a higher proliferative capacity. These cells also showed no signs of being cancerous or pre-cancerous^[2].

Cells used for producing cultivated meat aren’t HeLa cells

HeLa cells are a cancer cell line that was the first immortal human cell line ever cultivated. But these cells have nothing to do with those used to produce cultivated meat.

To start with, HeLa cells are human, while the ones used for cultivating meat are chicken cells. Furthermore, HeLa cells derive from an aggressive cervical cancer that caused the death of the woman from whom they were collected, Henrietta Lacks. These cells became immortal after Lacks was infected with the human papillomavirus. The virus blocked the cellular mechanisms that regulate cell division and caused some cells in the neck of her uterus to become cancerous.

This means that HeLa cells weren’t intentionally immortalized as the video suggested, but they were cancerous before being cultivated in the laboratory.

In any event, HeLa cells aren’t used to produce cultivated mea. And as with any other food product, cell-cultured meat is subject to food safety regulations. The USDA doesn’t allow animal meat containing “cancerous lesions or tumors” to enter commerce or the food chain. Therefore U.S. regulators wouldn’t have approved a food product containing such cells.

There is no evidence of a plausible mechanism by which cell-cultivated meat might cause cancer

One possible misinterpretation that can arise from comparing cultivated meat with cancerous cells is that this product causes cancer in the people who consume it, as this article in The People’s Voice claimed. While the potential of a novel food to cause or increase the risk of cancer in people is a legitimate concern, our knowledge of how cancer works and how cell-cultivated meat is produced doesn’t provide evidence to support this possibility.

In 2023, the Food and Agriculture Organization of the United Nations and the World Health Organization published a safety assessment of cell-based food. On page 122, the report explained that the possibility that a cell from these products remains alive and enters the consumer’s body is “extremely low”:

“For this to happen, all of the following events would need to occur. First, the cells would need to be capable of remaining alive for an extended period after being removed from the environment of the bioreactor that provides a steady supply of nutrients, dissolved oxygen, and a fixed temperature. The cells would also need to survive actively adverse conditions during a series of steps following harvest. These would typically include conventional food processing, handling and storage at cold or freezing temperatures, and consumer preparation including thermal cooking. A hypothetical cell that survived these steps and remained alive in the final food product would then need to survive gastrointestinal digestion, cross the gastrointestinal barrier layer intact, enter into the blood circulation, evade immune surveillance and attack in the body in spite of being from a non-human species, and finally proliferate in the body.”

The report added that “current scientific knowledge does not support the plausibility of human cancer contagion via introduction of cells even from other humans”.

Conclusion

In summary, the claim that cell-cultivated meat is made out of cancerous cells like HeLa cells, is inaccurate. This product is made of immortalized cells that show no sign of being cancerous. Based on our current understanding of this technology and of cancer, there is no evidence of any plausible mechanism for the immortalized cells to cause a tumor when eaten, even if the cells survive the multiple processes that they undergo, which is an extremely unlikely possibility.

UPDATE (24 July 2023):

We updated our review to include information about the person who made the claim in the video. This information appears in paragraph four.

REFERENCES

• 1 – Hanahan and Weinberg (2000) The Hallmarks of Cancer. Cell
• 2 – Pasitka et al. (2022) Spontaneous immortalization of chicken fibroblasts generates stable, high-yield cell lines for serum-free production of cultured meat. Nature Food.