Elliot Swartz Profile picture
Scientist @GoodFoodInst, analyzing progress & challenges in #cultivatedmeat & alternative proteins. Opinions my own. BlueSky: @elliotswartz.bsky.social

Feb 14, 2023, 27 tweets

Some thoughts on (1) whether immortalized cells for #cultivatedmeat production should be compared to eating cancer (2) whether consuming them would give you cancer & (3) whether long-term studies are needed to ensure the safety of cultivated meat...

bloomberg.com/news/features/…

(1) The article says immortalized cells are precancerous or in some cases cancerous

There are 6 hallmarks of cancer, immortality is 1 of them. Having 1 feature of a complex phenotype doesn't mean it is that type.

You can't equate immortality to cancer.

en.wikipedia.org/wiki/The_Hallm…

(1) Thus, while all cancers are immortalized, not all immortalized cells are cancer. Sorta like how not all rectangles are squares.

To become cancer, a transformation involving the loss of control in various aspects of cell growth & regulation is one event that occurs.

(1) In cultivated meat, this transformation is what would likely get cells excluded from further use.

When using immortalized cells in production, manufacturers have a large incentive (from a quality, not safety perspective) to use predictable, controllable, & stable cells.

(1) To some extent, evaluating this is baked into the regulatory process, as manufacturers and regulators both like to see and work with stable cell lines that reproduce the same end-product via the same process time and time again.

(1) So, it's very unlikely that the cells used in #cultivatedmeat production that reach consumer plates would fit definitions we typically apply to cancer.

It just doesn't make sense to use those cell types in production.

(1) In contrast to avoiding questions related to this "PR nightmare," some companies are openly publishing the characterization of their immortalized cells.

Additional data will come to light as companies go through regulatory approval processes.

(1) So, the only thing this aspect of the article does is open the door for bad faith actors to engage in relentless sealioning over the "issue."

It's now almost a certainty this topic will appear and re-appear in comment threads for years to come.

en.wikipedia.org/wiki/Sealioning

(1) It's as if it was known this were going to be the case and was perhaps the whole purpose of the article in the first place...

(2) Credibility of the article being written in good faith sorta goes out the window, knowing the topic is basically irrelevant from a safety perspective

There's no evidence that cancer has ever been passed/spread from ingesting cells — immortalized, cancerous, or not

(2) The FDA's review of @upsidefoods cultivated chicken produced from 2 forms of immortalized cell lines described the scenario as "a hypothetical hazard" and declared the cells' properties no different from those from other animal cells.

"Hypothetical" is used intentionally

(2) One of the reasons we know this isn't a food safety hazard is b/c humans consume nearly 500 million tons of meat/seafood annually. A small % of this is actual precancerous lesions & microscopic tumors — visual inspections can't detect everything & are subject to human error.

(2) I've also seen concern over whether metabolites from immortalized or cancerous cells are a safety hazard. However, it's convention that animal metabolites aren't toxicants. There is no safety threat even if immortalized cells transformed into a cancerous state.

(2) So, safety concern over ingesting cancerous cells is neither pertinent nor unique to cultivated meat

But you can now be assured that the cultivated meat industry will have to answer more questions about it than the conventional meat industry, hurting its public perception

(3) Lastly, even though every scientist they spoke to concluded it's not a safety concern, the article's subheader states 'but there aren't decades of data to prove this!' They quote Robert Weinberg (cancer expert, not a food safety/risk assessment expert) to support this notion.

(3) This is spreading FUD — fear, uncertainty, doubt. A tactic used to deny scientific consensus on tobacco, climate change, etc.

Which begs the question, are long-term safety studies needed to ensure the safety of novel foods like cultivated meat?

en.wikipedia.org/wiki/Fear,_unc…

(3) First, humans have safely consumed meat for thousands of years. On a biochemical and genetic level, #cultivatedmeat is the same as the meat that comes from an animal. This is validated during the regulatory process prior to market entry.

fda.gov/media/163261/d…

(3) So if the end product is the same, evaluation of safety shifts primarily to a focus on the inputs (mostly the cells and media) and the production process itself.

Watch this webinar for a safety overview of inputs used in cultivated meat production:

(3) Inputs used in the media (glucose, vitamins, amino acids, etc) will have a safe history of use in foods (if they don't, manufacturers will need to go thru a long process to establish their safety). And the production is very similar to fermentation processes (beer, yogurt)

(3) Regulators & food manufacturers have robust management practices to ensure the safety of all foods. The practices ensure potential hazards are identified & appropriate controls are in place to produce food where the quality & nutrition is validated.

en.wikipedia.org/wiki/Hazard_an…

(3) We all know how damaging a negative food safety event would be for a developing industry.

If regulators felt they didn't have sufficient information to evaluate the safety, we wouldn't see products making it to market. It would be far too risky.

(3) But this isn't the case. Because there is nothing inherent to cultivated meat that makes it too difficult to evaluate its safety.

This is how "novel foods" and ingredients are successfully brought to market every year w/o needing 'decades of data' to ensure safety.

(3) Please see this video to get a sense of how cultivated meat is made in an actual production facility and how safety is evaluated. Be sure to compare this to a slaughterhouse when watching.

In summary, this article is more about JAQing off then it is about addressing real challenges faced by the industry.

"The industry had realized you could create the impression of controversy simply by asking questions" - Merchants of Doubt

rationalwiki.org/wiki/Just_aski…

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Lastly, in April 2023 an FAO report focused on food safety, which included input from a panel of 23 international experts, concluded that there was "no credible pathway to harm" related to the consumption of immortalized cells.

fao.org/3/cc4855en/cc4…

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