While not available at your local supermarket today, heart-healthier ham, bacon and pork chops could in the future join mackerel, tuna and salmon as sources of omega-3 fatty acids, a University of Missouri animal scientist said.
In a world first, a national group of researchers has made pigs that produce the beneficial compound, which is known to improve cardiovascular fitness and reduce the risks of heart disease. Their research appeared in the April 6 issue of Nature Biotechnology.
“All mammals, humans included, do not naturally produce omega-3s, so the only way to get these essential fatty acids is through your diet,” said Randall Prather, MU animal scientist whose laboratory produced the pigs. “Omega-3 pork would give consumers a new choice and avoid concerns about heavy metal contamination in some fish species.”
The five Large White boars born in Columbia, Mo., last November are producing fatty acids levels as high as or higher than pigs fed an omega-3-rich diet, he said.
In addition to consumers, pork producers also could benefit from pigs that produce omega-3 fatty acids. “The pigs themselves would be healthier, so sows could remain in a breeding herd longer and reduce replacement costs,” Prather said. “Consumers also would likely be willing to pay a premium for omega-3 pork, so there could be a value-added economic benefit.”
Prather noted that such consumer and agricultural benefits, if they materialized, would be many years away. Although some genetically modified crops are approved for human consumption, he said, no genetically modified animals have been approved.
“It’s not just around the corner,” he said. “The Food and Drug Administration treats transgenic animals more like new drugs, and the scrutiny is much higher than for crops. I’ve heard estimates that it would cost $200 million to $300 million to get a transgenic animal through FDA approvals.”
However, the modified pigs will provide an immediate benefit to researchers around the world studying the impacts of omega-3 fatty acids on cardiovascular, immune and reproductive health.
“Because of similarities in body size and physiology, pigs are an ideal animal model for studying human health,” said Prather. “Mice that produce omega-3 have been created, but the mouse model is too small for taking tissue samples or studying impacts on blood flow, for example.
“Having a large animal model means new research avenues will be opened. Studies will be improved because these pigs will have higher levels of omega-3 with less variation from animal to animal.”
To produce omega-3 fatty acids in the pigs, researchers inserted a gene called “fat-1,” which was isolated from the roundworm, Caenorhabditis elegans. The fat-1 gene provides the genetic instructions for producing an enzyme that converts less desirable omega-6 fatty acids, found in cereals, whole-grain bread and baked goods, to omega-3.
Prather, who collaborated with laboratories led by Yifan Dai and Rhobert Evans at the University of Pittsburgh and Jing X. Kang at Massachusetts General Hospital, explained that while cloning initially was used to insert the fat-1 gene, conventional breeding will be used to increase the herd.
“Omega-3 production in these animals is like any other heritable trait,” he said. “These five males have one copy of the gene, so when we breed them to females, only half of their offspring will have the gene. We can crossbreed the offspring to produce animals with two copies of the gene, which may increase omega-3 levels further.”
Later this year, the National Swine Research and Resource Center, a clearinghouse of swine models for biomedical research, will open on the MU campus. The omega-3 pigs will be integrated into the center’s collection and made available to researchers around the world, said Prather, who co-directs the center.
The National Institutes for Health provided funding for the project.
Jason L. Jenkins is a senior information specialist, Extension and Ag Information, University of Missouri. e-mail: [email protected]