From hot dogs to crispy bacon, US food staples could be made of gene-edited meat as early as 2026. Yes, really: the US Food and Drug Administration (FDA) recently approved the farming of a specific kind of genetically enhanced pig. And regulators around the world may not be far behind.
So, should we be worried? Will this pork truly be safe to eat? And just how ethical is it to create these pigs?
The first thing you should know: not every gene-edited animal will be directly spawned from a lab. Rather, such livestock are merely bred from animals whose DNA was edited early on – often at the single-cell or fertilised egg stage – to give them beneficial traits.
And no, this gene editing isn’t about making pork taste better – it’s about protecting pigs from disease.
For instance, British company Genus has now farmed pigs with a genetic tweak that makes them resistant to PRRS (Reproductive and Respiratory Syndrome), a virus that attacks pigs’ immune cells. PRRS is a major threat: it can kill piglets, trigger miscarriages in pregnant sows, and weaken pigs’ immune systems, leaving them vulnerable to other infections.
These genetically enhanced pigs are even less of a novelty when you consider there is no effective vaccine for PRRS.
The stakes are enormous. In the US alone, efforts to control the spread of PRRS cost the pork industry an estimated $1.2bn (£878m) every year.
And when the virus does break through, the consequences can be devastating. In 2006, a major outbreak in China infected over 2 million pigs and resulted in 400,000 deaths.
CRISPR bacon
How heavily are these pigs being altered – and at what cost to their welfare? They’re fair questions. But in reality, the change is surprisingly minimal.
To stop the PRRS virus in its tracks, scientists snipped out a small section of pig DNA – part of the CD163 protein, which the virus uses to enter pig cells.
Pigs with the edited gene are resistant to almost all known strains of PRRS but are otherwise, Genus claims, “the same as conventional pigs”. And despite initial concerns that the virus could evolve to recognise and avoid the edited protein, that hasn’t happened so far.
According to Dr Christine Tait-Burkard, a Research Fellow at the University of Edinburgh’s Roslin Institute, who worked with Genus to develop the original gene-edited pigs, the natural CD163 protein they edited is “like nine beads on a string.” The edit removes only bead number five.
This tiny change, she explains, is enough to stop the virus taking hold, but not enough to affect the protein’s other functions (these include helping dispose of damaged red blood cells).
As Tait-Burkard explains, the edit is one that could also be naturally present in some pigs. “The chances are that there’s a pig somewhere in the world that’s resistant to this virus,” she says. “But we just don’t have the time to naturally breed this in. That’s where we have to start using biotechnology to integrate it into the breeding herd.”
To make the edit, the researchers employed a gene-editing toolkit known as CRISPR, a Nobel Prize-winning technology now widely used in scientific research for its speed, precision and low cost. The CRISPR toolkit uses a ‘guide’ sequence to target DNA with protein ‘scissors’ – natural proteins, originally discovered in bacteria, that are capable of making the necessary cuts. Minor removals, like those in PRRS-resistant pigs, inactivate certain genes.
The new norm?
When they reach supermarket shelves, PRRS-resistant pigs are expected to be the first widely consumed gene-edited animals. They won’t, however, be the first to reach US plates.
Hypoallergenic ‘GAL-safe’ pork, designed to be suitable for people with red meat allergies, was approved in 2020. And in 2022, the FDA gave the green light to so-called SLICK cattle – cows with an edit based on a natural gene variant found in tropical cows, which codes for shorter hair and greater heat resilience. Genetically modified, fast-growing ‘AquAdvantage’ salmon is also available in the US but is mostly sold to restaurants.
The situation is slightly more complicated on the other side of the Atlantic. Currently, gene-edited foods can’t be sold in the EU. And the Genetic Technology (Precision Breeding) Act provides a basis for breeding of gene-edited food in England (but not the wider UK), though it’s only just being implemented for crops.
But even if legislation changes worldwide, will consumers be lining up to put gene-edited sausages and bacon in their shopping trolleys?
It’s not clear yet how the new gene-edited pork will be labelled. But Dr Katie Sanders, a food systems communication specialist at North Carolina State University, notes that, compared to traditionally genetically modified (GM) foods, “There are a lot of folks who think that there is greater potential for consumer acceptance.” She says this is partly because they’re considered more natural.
In the 1990s and 2000s, genetically modified (GM) crops generated headlines and consumer concern about ‘Frankenfoods’. Ultimately, though, many GM crops were approved and the majority of scientists consider them safe to eat. These modified crops often carry foreign DNA – ‘Bt’ corn, for example, contains a gene from the bacterium Bacillus thuringiensis, enabling it to make a protein that kills insect pests.
The current generation of CRISPR-edited food products, by contrast, only contain changes that could naturally occur within the species. Scientists aren’t inventing entirely new kinds of pigs.
Sanders and her colleague, associate professor Jean Parrella, from Texas A&M University, recently conducted a national survey of over 2,000 Americans to gauge how consumers feel about CRISPR-edited pork products. The results are awaiting publication, but Sanders says they suggest men are “more likely to express intent to purchase CRISPR-edited pork.”
Also more likely are those living in urban areas (compared to rural areas) and those with lower-level educational qualifications (compared to those with degrees).
Asked how producers could convince more consumers to try gene-edited meat, Parrella says they’ll need to focus on “responsible use and ethical considerations around CRISPR applications”.
Early marketing for PRRS-resistant pigs suggests these considerations are already being taken into account. A division of Genus called The Pig Improvement Company – yes, that’s really what it’s called – is emphasising improvements to animal welfare, reduced antibiotic use and positive environmental impacts.
Assuming their message takes off, could more gene-edited animals be headed for our dinner tables? Maybe. Scientists at the Roslin Institute are currently working on edits to tackle other livestock diseases, including bovine diarrhoea virus.
But Tait-Burkard explains that engineering resistance to certain viruses, like bird flu, requires too many edits, or edits that would be detrimental to animal cells. She says that the protein they edited for pig PRRS resistance is just “a beautiful target”, the likes of which is hard to find.
For other, productivity-related characteristics – such as increased milk production, or meat quality – farming has already developed efficient breeding techniques to achieve these goals. It’s therefore unlikely that expensive gene-editing technologies will be used to create ‘super’ meat anytime soon.
However, if gene editing can protect animals, reduce antibiotics and ease environmental pressures – without compromising their welfare – it may soon become more normal than novelty.
Read more: