January 16, 2010

Stem Cell Technique Holds Promise For Meat Production

A technology that allows pig stem cells to be converted into strips of meat might one day offer a solution to world hunger and a green alternative to raising livestock, scientists say.

Researchers in the Netherlands have been growing pork in laboratory environments since 2006, and while they acknowledge they have not perfected the texture or even tasted the meat, they say the technique has broad implications for the world's food supply.

"If we took the stem cells from one pig and multiplied it by a factor of a million, we would need one million fewer pigs to get the same amount of meat," biologist Mark Post with Maastricht University told the Associated Press.

The university is part of the In-vitro Meat Consortium, a network of publicly funded Dutch research institutions that is conducting the experiments.

Post said the meat's texture resembles that of a scallop "“ firm, but a bit squishy due to its lower protein content.

Other researchers in the U.S., Japan and Scandinavia are also working on ways to make meat in the laboratory, but the Dutch project is the most advanced, said Jason Matheny with Johns Hopkins Bloomberg School of Public Health in Baltimore, who has studied meat alternatives.

The U.S.-based research was funded by NASA, which had hoped the work might ultimately allow astronauts to grow their own meat in space.  However, the space agency abandoned the initiative after results produced disappointingly thin sheets of tissue, deciding instead that it would be better for astronauts to simply eat vegetarian.

To produce pork in the lab, Post and his team isolated stem cells from pigs' muscle cells, and added them to a nutrient-based stew that helped the cells replicate to the targeted number.

To date, the scientists have only been able to create strips of meat about half an inch long.  Post estimates it would take about 30 days of cell replication in the lab to make a small pork chop. 

But the technology offers promising potential.  For instance, fish stem cells could be used to produce healthy omega 3 fatty acids, which could be combined with the lab-made pork instead of the typical artery-clogging fats found in livestock meat.

"You could possibly design a hamburger that prevents heart attacks instead of causing them," Matheny told the Associated Press..

Post said the meat they have made so far could be used in sausages or hamburgers. 

The biggest challenge now is reproducing protein content. Conventional livestock meat consists of up to 99 percent protein, whereas the lab meat is roughly 80 percent protein.  Post said the lower protein content means the lab-made meat would not likely taste like pork.

The researchers say the technology should apply to other meats as well, including chicken, beef and lamb.

But some experts caution that lab-made meats could pose potential health threats for humans.

"With any new technology, there could be subtle impacts that need to be monitored," Emma Hockridge with the Soil Association, Britain's leading organic organization, told the Associated Press

Hockridge said organic farming relies on crop and livestock rotation, and that removing animals could damage the ecosystem.  And it might take some time to prove the new technology isn't harmful to humans, she said.

Other experts are skeptical that lab-produced meat could ever match the taste of real meat.

"What meat tastes like depends not just on the genetics, but what you feed the animals at particular times," biochemist Peter Ellis with King's College London told the AP.

"Part of our enjoyment of eating meat depends on the very complicated muscle and fat structure...whether that can be replicated is still a question," he said.

If the technology proves out, the lab-produced meat could be a big benefit for the environment, some experts say.

Hanna Tuomisto with Oxford University, who studies the environmental impact of food production, said using lab-produced meat could theoretically reduce greenhouse gas emissions by up to 95 percent.  

"In theory, if all the meat was replaced by cultured meat, it would be huge for the environment," she told the AP.

"One animal could produce many thousands of kilograms of meat."

Another benefit is that since lab meat can be "raised" with fairly few nutrients like amino acids, fats and natural sugars, it would reduce the need for the large amount of crops needed to nurture conventional livestock.

Widespread adoption of the technology also holds the potential to increase the world's meat supply, which could help fight global hunger, Tuomisto said.

Post hasn't determined the commercial production costs of the technique.  However, given that it would require less land, water and energy he estimates it would be equivalent to or lower than that of conventionally produced meat.

One of the most significant obstacles will be ramping up production to meet soaring global demand.  By 2050, meat consumption is expected to double from current levels as developing nations consume more meat, according to the Food and Agriculture Organization.

"To produce meat at an industrial scale, we will need very large bioreactors, like those used to make vaccines or pasteurized milk," said Matheny, who thought the lab-produced meat could be commercially available within the next few years.

Post estimates it could take a bit longer, or about a decade.

For now, processed meats like hamburgers or hot dogs are the only types of meat they are proposing to create with the technique.

"As long as it's cheap enough and has been proven to be scientifically valid, I can't see any reason people wouldn't eat it," Stig Omholt, a genetics expert at the University of Life Sciences in Norway, told the Associated Press.

"If you look at the sausages and other things people are willing to eat these days, this should not be a big problem."


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