MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. It's a futuristic Food Wednesday. We begin with some dietary suggestions. Test tube tenderloins, lab chops, Petri pork and Franken-burgers or in other words, meat from a lab, not a slaughterhouse. While it isn't coming soon to a supermarket near you, it is a scientific pursuit that's gaining momentum.

MR. KOJO NNAMDIAnd as the world population grows, demand for meat is on the rise. And a couple of decades from now, in vitro meat just may be what's for dinner. Joining us to discuss this is Michael Specter. He joins us from NPR's Bryant Park studios. He's a staff writer with the New Yorker where he often covers science, technology and public health. He's also the author of "Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet, and Threatens Our Lives." Michael Specter, thank you for joining us.

MR. MICHAEL SPECTERMy pleasure.

NNAMDIJoining us by telephone from the Netherlands is Mark Post. He's a professor of vascular physiology at Maastricht University in the Netherlands where he is working on the development of in vitro meat. Mark Post, thank you for joining us.

MR. MARK POSTWelcome.

NNAMDIIt's a conversation we're inviting you to join by calling 800-433-8850. Would you eat meat that came from a lab instead of from an actual animal? Why or why not, 800-433-8850? You can send us an email to kojo@wamu.org. Michael Specter, you have covered science as a journalist for decades. What sparked your interest in in-vitro meat?

SPECTERWell, a variety of things. I've been writing about animal issues for a while about population health and the environment. And if you look down the road, not very far as you mentioned, a lot of people are going to be on this planet in 30 or 40 years. And we're going to probably need about 70 to a 10 percent more food then we have now.

SPECTERAs people get richer, which thankfully they are doing, particularly in places like China and India, they tend to eat more meat. So that demand for protein is very difficult to square with our environmental issues. And along comes this possibility of making wonderful protein that wouldn't have those deleterious effects. So it certainly seemed like something worth writing about.

NNAMDIMark, earlier in your career, you worked on crafting arteries to replace damaged ones in human hearts. What made you decide to shift your focus to creating meat?

POSTWell, it started with a coincidence that I got involved in this project of tissue engineering of skeletal muscle because all the principles that they are using basically started in medical research. And then, at some point, this guy from Amsterdam came along and said, hey, can we make meat from stem cells? And let's try and do that. And I realized that it could have a tremendous societal impact and I decided it was worth studying it and developing it.

NNAMDIBut from reading Michael's writing, it's my understanding, Michael, that Mark's family was a little puzzled by the choice.

SPECTERWell, you'd probably have to ask him, but I think he's a very distinguished physician and researcher and it's pretty easy to go home and say you're trying to build the heart or you're trying to build the lung. It's probably more difficult to say, I'm working on a new hamburger.

NNAMDIMark, what, indeed, was your family's reaction?

POSTWell, my kids still laugh about it. And I guess they get a lot of comments from their peers as well. And also the older family members sort of looked at me, you know, are you really serious? Is that what you want to do with your career? But when you explain what the potential impact is of such a thing and why it drives me to do that, then it makes perfect sense to most people.

NNAMDIIn case you...

POSTBut my kids still laugh about it.

NNAMDI...in case you're just joining us, that's the voice of Mark Post. He's a professor of vascular physiology at Maastricht University in the Netherlands where he's working on the development of in vitro meat. That's exactly what we're discussing today with him and with Michael Specter, staff writer at the New Yorker where he covers science, technology and public health.

NNAMDIAnd inviting your calls at 800-433-8850. Do you think man-made foods will be a bigger part of our future meals, 800-433-8850? Now, Mark, how different or similar is the process of producing a new artery compared to generating meat in a lab? Could you walk us through the basic scientific process you're involved in here?

POSTWell, the principles are very similar. So you start with a cell, either a stem cell or in the case of arteries, you can use other cells. But for meat, you would need to have skeletal muscles stem cells that are sitting in our muscle waiting for it to be injured and then repair the muscle. And you can take those out, you can let them multiply for many, many times so that you can get a whole lot, probably a trillion or even more from a couple of cells. And then because these are designated skeletal muscle stem cells, they will with a few tricks that are not difficult and not too elaborate, you can start to differentiate them into muscle again.

POSTSo they will become muscle cells with all the features of a regular muscle cell. And then you can make tissues out of those with, again, tissue engineering techniques that were developed for medical purposes. And that's the basis of meat. And in addition, and that's what we're doing now, is also replicating that same process, but now for set tissue derived stem cells to make the fat component.

NNAMDIMichael Specter, I was really glad to hear Mark say that's the basis of meat, because it's a question that seems simple, Michael, but what is meat and does the stuff scientists are working on in labs match the definition we're used to?

SPECTERWell, technically meat is any part of an animal that isn't bone. And usually it refers to muscle tissue. And that's what those guys are mostly working on. And that's what we tend to think of as meat. That's what pork and hamburgers and steaks are. So, yeah, I think it's -- there are many people who are taken them back at this idea when it's new. But when they think about it, as Mark said, they get a little more used to it. And I -- it's meat.

NNAMDIAnd the scientists that you interviewed were very clear that what Mark is making is not a meat alternative. It is meat, correct?

SPECTERYeah, actually one of his colleagues, I said something about, this -- I basically said to her this is a pretty interesting alternative, and she said, it's not an alternative, it's meat. And she's right, I mean, it's exactly the same. You know, you can have a philosophical debate about whether meat needs to be born in a field or whether it can be grown in a vat. But in terms of the physiology of it, it is meat.

NNAMDIIn decades past, everyone from science fiction writers to Winston Churchill, I read a statement he made about chicken in 1932. They all predicted a future in which dinner tables would be laden with man-made meat. When did that idea turn the corner from sci-fi to potential reality? First Michael, then Mark.

SPECTERI think, you know, during the 20th century, there were experiments where people were able to keep tissue alive outside the body in culture. And the very strong push to make extra parts for the body has meant that we've moved really fast with tissue generation. And I think when you add those two things together, people, you know, within the last 25 years really got onto the bandwagon. The guy that I wrote about who started it in the Netherlands, he really came from it from a completely different angle.

SPECTERHe was a kind of spoiled colonial kid who was taken prisoner during World War II, spent, I think, almost the entire war in very, very brutal camps, Japanese prisoner of war camps in Indonesia. And he came out of there seeing some brutality to animals and at some point when he went back to the Netherlands, it just sort of had a eureka moment and said why can't we make this stuff in a lab?

NNAMDIAnd then you come in, Mark Post. At what point did you realize that this dream, this possibility, could, in fact, become a reality?

POSTWell, actually the first time -- the techniques, again, that we are using of developing these muscles outside of the body have been out there for quite some time. People are studying it and especially in the United States, a couple of labs have been studying this as a model system to test drugs and to test physiological principles.

POSTBut they never really came up with the idea, I think, that's probably what it is, to make meat out of that or they thought it was just not enough status for them as scientists to work on that. When I was exposed to the ideas of Willem van Eelen, of whom Michael just spoke, that I realized that it was a possibility to make meat out of it and that we, in fact, should do it and see how far we can take it.

NNAMDIOn to the phones. Here is Jim in Easton, Md. Jim, you're on the air. Go ahead, please.

JIMYes, hi. Interesting conversation. It occurs to me, there's some rational fear or distrust that may come from that. But having said that, if this is a meat-like substance or a meat protein or a true muscle, would it be possible to actually insert, like, Omega 3 fatty acids in some higher concentration that would then make it a healthier meat and is that a real possibility? It's actually exciting.

NNAMDIFirst you, Mark Post.

POSTYeah, yeah, that's an excellent idea. In fact, so good that we had that same idea ourselves. Yeah. And, I mean, there seems to be even a difference in livestock meat if a cow is being fed a food or whatever it's being -- whatever it's grazing. And when it's grazing, it turns into -- the meat has actually higher Omega 3 fatty acid content.

POSTSo that tells you or that tells me, at least in principle, that the biochemistry of these cells is such that they are able to make polyunsaturated fatty acids or Omega 3 fatty acids. And that we should be able, in the lab, to replicate that by controlling all the variables that we can in the lab and then measure how much Omega 3 fatty acids are being made by these. And then, yes, we can indeed construct a healthier, less cholesterol increasing type of meat.

NNAMDIAnd I...

JIMThat's really fascinating.

NNAMDI...and Michael Specter, I suspect for Americans, the notion that we could have a meat that is better for us than the meat that we are currently eating would be a selling point.

SPECTERWell, it would have to be. I think it was Mark Post who said to me or turned me onto the idea that someday a doctor might actually prescribe a hamburger rather than pro-scribe it because if you can engineer what you want into it, it could be healthy and good for you. And I mean, we live in a country where there are epidemics of obesity and diabetes, much of that is related to eating too much meat and saturated fat. And if this could be an alternative that not only didn't have that, but had the things that counteract it, even those people who seem to be put off at first would come around.

NNAMDIWell, let's talk to one of those people who may seem to be put off at first. Here is Dwight in Virginia. Dwight, you're on the air. Go ahead, please.

DWIGHTThanks for taking my call. I appreciate it. Yeah, I mean, I'm a fairly well educated person. Some of that education has come from some nontraditional alternative kinds of research. And, you know, the idea of that scares me. It scares me for the same reason that companies like ADM and Monsanto decided that it was a good idea for us to have genetically modified organisms in making the frankencorn and frankenfruits and things like that. And then coming back and saying, oh no, it'll be -- not be a problem to plant that corn in this field. It won't affect the corn in the other field. Well, of course there's wind and there's pollen. And it blows and it goes to another corn field.

DWIGHTSo it's that kind of mentality that kinda scares me. It's that conventional straight line, this is better. More money, more technologies and more food is the answer to our problems. And I think that a lot of people are scared of it not for lack of education or lack of understanding, but I think it comes from a deeper -- I think it comes from a deeper part of our soul. I mean, (unintelligible) ...

NNAMDIWell, allow me to have Michael Specter respond because...

DWIGHT...more natural -- you know, things in their natural state are safer and better. You know, raw milk is better than pasteurized milk (unintelligible) ...

NNAMDIAllow me to have Michael Specter respond because, as I mentioned earlier, he is the author of "Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet and Threatens our Lives." Dwight, why is -- I mean, Michael, why is Dwight's thinking not rational?

SPECTERWell, the only thing he said that I think I agree with is that there is fear deep in the soul of people about this. When he starts talking about genetically engineered organisms in then Monsanto, I have to say whoa. Monsanto's a company. It's not a science, it's not a process. We are talking about a process. And this particular process has been planted in billions of hectors over 30 years. And not one person has ever been shown to be made sick by it.

SPECTERThere are environmental issues. There will be environmental issues with this. Those things can be addressed but it has nothing to do with the corporation. If we want to address them we can address them. And as to the naturalness of what's out there, I've never seen an appropriate definition of natural. I don't know what that means.

NNAMDIIt's your turn, Dwight.

DWIGHTI'm just concerned that the food's not in its natural state. It's not in its raw state and it's definitely fact that anything in its raw or more raw state and more the state in which that it's closer to when it's grown -- I know we're talking about meat versus vegetables here and fruits, but the body can't process things that are fake. It can't process them in the same way that they would process foods that are (unintelligible) ...

NNAMDII...

SPECTERThis isn't fake.

NNAMDII guess that's the point...

DWIGHT(unintelligible) ...

NNAMDI...I guess, Dwight, the point that's being made here is this is not a meat alternative. And as Michael was just about to say, this is not fake.

SPECTERAnd also the idea that somehow everything in nature is benign and blissful, nature kills. Nature kills a lot more than any other organism. There are lots of things out there that are dangerous. So the idea that everything in its raw state is better than anything that's been dealt with by man is, I really do believe, naïve. It doesn't mean that refined wheat is better than whole wheat. We know that it isn't. And there are lots of such examples. But to just say, gee, nature's great and manmade things or man altered things are horrible is, for one thing, to ignore all of modern science.

NNAMDIGot to take a short break. Dwight, thank you very much for your call. When we come back, we will continue our conversation on in vitro meat. Food Wednesday looks ahead. 800-433-8850 is the number to call. What questions do you have about the science behind in vitro meat? Give us a call, 800-433-8850 or send email to kojo@wamu.org. I'm Kojo Nnamdi.

NNAMDIWelcome back to our Food Wednesday conversation on in vitro meat. We're talking with Mark Post. He's a Professor of Vascular Physiology at Maastricht University in the Netherlands where he's working on the development of in vitro meat. And joining us from the NPR's Bryant Park studios is Michael Specter. He's a staff writer at the New Yorker where he often covers science, technology and public health. He's also the author of "Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet and Threatens Our Lives."

NNAMDIWe've got a lot of responses to how people would feel about in vitro meat on Facebook. Jeanine says, "I don't think I would eat it, but there are plenty of products on the shelves now that I wouldn't eat either." Myla says, "I would totally eat that. I'd love to be able to get an occasional burger without having to feel guilty about it." And Tracy on Twitter reacted to the subject by saying, "Yeah, really?" Here is Krista in Falls Church, Va. Krista, you're on the air. Go ahead, please.

KRISTAHi. Yeah -- excuse me -- yeah, I'm a vegetarian and I'm an ethical vegetarian, those for concerns of animals and for the environmental issues that raising animals causes. And I'm kind of curious. I read an article recently that said that they're going to have meat substitutes very soon that taste exactly like meat. And I'm wondering which one's going to come first, the in vitro meat and this and whether or not there's going to be issues making in vitro meat taste like meat because perhaps it will not have fat in it like a natural meat might have.

NNAMDIWell, I've got to keep repeating, it is not an alternative. It is meat, but...

KRISTAYes, I was comparing alternatives to the in vitro meat in terms of taste and...

NNAMDISure. Well, here's Mark Post. Care to comment?

POSTYeah, yeah, that's an excellent question. And of course, the reason why we did this and why we think it's a good way of producing meat is because cows and pigs are very, very inefficient in converting vegetable proteins into animal proteins. However, if you can make meat substitutes that are indistinguishable from meat and you can make them from vegetables and proteins alone, and there's no way you can beat that with an in vitro meat type of approach.

POSTSo, yes, if we can come up with meat substitutes that are exactly the same that are indistinguishable and made from vegetable proteins, that would be preferable over any type of other -- any other way of producing meat. I totally agree. However, I don't see that happening in the near or even far future and that's why we are taking this approach. But, you know, maybe I'm wrong. And then I'm also happy because then we found another way to solve the problem of the scarcity of meat in the future.

NNAMDIKrista, thank you very much for your call. We talked with the president of PETA, People for the Ethical Treatment of Animals, Ingrid Newkirk, who had offered a million dollar reward to anyone who could make in vitro chicken available for purchase in ten states. That offer actually expires in June of this year. We talked to her on January 9 of this year and I asked her whether she thought that vegetarians, people like Krista, would embrace a lab-grown meat product.

INGRID NEWKIRKSome will, Kojo, and some won't and have let me know rather vociferously that they won't. It's a constant bone of contention. That would be a terrible pun. But I'm very hot for this research to bear fruit, so to speak. It's a very exciting area of science. It's been going on now for about 14 years. It was languishing. We have helped fuel it a bit. But what happens is real animal cells are grown in culture using a mushroom base and they turn into meat. You can grow this meat. You can grow layers of this meat. There's a long way to go, but it will be real meat, but it will be grown in the laboratory. No slaughterhouse.

NNAMDIAnd people have all kinds of moral and ethical concerns about that.

NEWKIRKWell, you know, it's funny because if you serve a hot dog from a real pig and they don't have any qualms, many of them are eating that, and it's worse. It's the nose of a pig, it's the rectal tissue, it's god knows what. But you say this is grown in culture in a laboratory and they think, ooh, I'm not sure about that. But it will be clean. There won't be e-coli, there won't be salmonella and there won't be slaughterhouses.

NNAMDIThat's the president of PETA, Ingrid Newkirk, talking about in vitro meat that we're discussing today. Michael, you described the Netherlands as the in vitro meat world's version of the Silicon Valley. How did that come to be?

SPECTERWell, I think it's this guy, William Van Eelen, who both Mark and I had mentioned earlier. He had this idea a long time ago and I think he ran around for years having people say, are you nuts. Because he's not a world class researcher the way Mark and his colleagues are, but he's a guy with a lot of energy and a really good idea. And eventually -- and I think the big thing was when stem cell work started to be valuable and understandable and people saw that you could change cells into different forms, then it became real.

NNAMDIOn to Russell in Washington, D.C. Russell, you're on the air. Go ahead, please.

RUSSELLHi. I was just curious, growing meat in this manner, would it consume less for energy and resources to grow this type of meat than, you know, having a cow grown the traditional way?

NNAMDIAnd, you know, we also got an email from Mark in Ruston who said, "Would the energy and resources needed to produce in vitro meat be significantly less than what's required to raise cows? I'm skeptical that we have the technological art required to do something more efficiently than nature." I'd like to hear you both on this. First you, Mark Post.

POSTYeah, of course we are still in its infancy and right now because, as Michael already mentioned, we're sort of struggling with getting this really ongoing on a larger scale so that we can make more progress in a shorter time. So that's why we decided to make this proof of concept, if you will, by the end of this year. But that will not be an efficiently made hamburger. And it will not be cheap. So we need -- after that we need to do a lot of work to make it more efficient.

POSTPeople have done with all sorts of assumptions and lifecycle analyses on a future in vitro meat or cultured meat production and estimated that the land usage would be about 80 to 90 percent less, energy about 60 percent less and water also about 60 percent less. Now you have to take those numbers with a grain of salt because there are all sorts of assumption that we still need to prove that we can make it more efficient than a pig or a cow can do that. But the sheer inefficiency of these animals as opposed to other organisms in the world in converting the vegetable proteins into animal proteins gives us a wide range for improvement.

NNAMDIMichael.

SPECTERWell, I think something that needs to be emphasized is how rapidly science moves. This is research that's going on in a variety of places and it went on, I think, more vigorously and intelligently in the Netherlands than almost anywhere else in the beginning. It may still be true but I think a lot of people are gearing up...

NNAMDIBecause the Dutch government had provided grant funding research for it, correct?

SPECTERThey did. And I think it's really important to understand that nobody -- not Mark Post, no serious person I know is selling this as the solution to the world's problems. We're going to have a lot of food problems, a lot of agricultural issues. And if this can be part of the solution, then that would be great. And I think what we need to do is forge ahead with the science. You know, my iPhone is more powerful than the first Apollo spaceship's computers and my iPhone doesn't cost that much. So that's what science does.

SPECTERThe Human Genome Project cost 3 billion bucks. You can do the same thing now for about 1,000. That took a couple years or more. This takes a day. I mean, that is what happens when you really focus. So I don't think we can really make judgments about what is going to happen in ten years. I think what we ought to do is work on the science and see where it takes us.

NNAMDIMark Post, we got this email from Amy -- or you can answer too, Michael -- "More specifically, who is funding this research now, agribusiness, pharmaceutical companies or some other entity? Very curious to know."

POSTWell, I cannot really disclose the name yet because the person wants to remain anonymous for another couple of months, but it's basically a philanthropic idea and not related to food industry. And they just see the potential and the potential benefits for environment and animals and so on so that's why they are funding it.

NNAMDIAnd we got an email -- or a Facebook post from Myla who says, and I'd like to repeat this, "I would totally eat that. I'd love to be able to get an occasional burger without having to feel guilty about it." The reason I'm repeating that, Mark, is because while it could be decades before meat using the techniques you're honing hits grocery stores, you hope to have the aforementioned burger created in your lab cooked up this fall. Tell us about that.

POSTRight. Well, so that's basically a proof of concept to try and generate sufficient interest in the world, in governments and financing bodies to get the resources and people and also researchers available to this endeavor so that we can make fast strides forward. So that's what it is. It's a proof of concept to say to all the skeptics out there, you know, it's doable. You can eat it. It's tasty, it's meat yet it's grown in a lab.

NNAMDIBut it's my understanding that making a burger is easier than creating a steak. How come?

POSTYeah, that's true. That's partly because the process that we're using -- or we're using that process because the tissue, if you keep it alive outside of the body, of course it needs oxygen and it needs nutrients. Now those substances need to defuse into the tissue and they can only defuse over so great a distance, actually very, very little. And so that's why we have blood vessels in our body to transport those nutrients and that oxygen to every sort of nook and cranny in our body.

POSTThe -- we don't have blood and we don't have blood vessels in this tissue. And so that's why we are staying with very, very thin pieces of muscle. And if we assemble them, if we make enough of them we can make any processed meat that you want, which by the way is about 50 percent of all the meat consumption in the world. Could we make steaks? Yeah, I think we can. And I think it will not be too difficult to move this from small pieces to a larger piece. But then we need to either make blood vessels in it or we need to create a channel system through which we flow the nutrients and the oxygen to keep the inner parts of the cuts alive.

NNAMDIMichael, I'd like to get back to the environmental question for a minute because there about a billion-and-a-half cows on the planet. They require a lot of food and produce a lot of methane gas. What would in vitro meat mean for the environment?

SPECTERWell, I think what it would mean, if you couple what you just said with the fact that we're growing as a planet very rapidly and in 50 years we're going to have another 3 billion of us, if we had viable in vitro meat, it would mean that we would require fewer of these animals and that means less water consumed, less grass, less land. And we're running out of land for a cow to graze on. So environmentally, it could be a really valuable asset in a world that's growing rapidly.

NNAMDIOkay. Back to the telephones now. Here is Anora in Arlington, Va. Anora, you're on the air. Go ahead, please.

ANORAHi. I'm sorry I missed the very beginning, so I don't really know who all of the players are, but I had to call when someone said that there is no proven incidents of anyone suffering any adverse health effects from any gamma products. I'm sorry, who was that that said that?

NNAMDIThat would have been Michael Specter.

SPECTERYeah.

ANORAI have to say, I don't know if any of you remember the old Dan Akroyd bit on "Saturday Night Live" when he was a toy manufacturer and he was promoting his product, bag of broken glass. Oh, you know, this stuff totally -- it's harmless, right? Well, look at this, and he shoves it down his throat and chokes to death, and that's what that reminded me of when he said, oh, the natural world has, you know, things that can kill you to. That's such a specious argument because right now we have no idea really what health effects any of these things have on us.

ANORAWe're just lab rats, and he said for 30 years these products have been used and nobody is suffering anything from it? I'm sorry. Look at the incidents of cancer, how it's risen over that time, and environmental sensitivities and allergies.

NNAMDIWell, Anora, I suspect that what Michael Specter is about to say is that there is a whole lot that we can speculate about, but we have to deal with what we really know, what science has taught us, but he can say that better than I can.

SPECTERYeah. I mean, there have been rise in cancer, rise in autism, which was erroneously linked to vaccines. Just because two things happen at the same time doesn't mean they're related, and it's very important. Now, if people could show evidence -- you have to remember, hundreds of billions of doses of genetically engineered -- I don't call it genetically modified because all the food we eat is genetically modified. It didn't all grow in the Garden of Eden.

SPECTERHumankind changed it over 10,000 years. This is a different way of changing it, and it's a more specific way, and it does have risks. I think it'd be crazy not to, but I think most of the objections come from people who object to big companies owning patents and lots of land and lots of seeds, and that's legitimate, and I pretty much agree, but that has nothing to do with the scientific advances. If you can put Vitamin A in a cassava so that a billion people in the developing world can get some protein and micronutrients that they do not get now, I'm sorry, that's not a bad thing.

NNAMDIAnora, thank you very much for your call. We're going to take a short break. When we come back, we will continue our futuristic food Wednesday conversation on in vitro meat and take your calls at 800-433-8850. If the lines are busy, shoot us an email to kojo@wamu.org, or simply go to our website kojoshow.org and join the conversation there. Do you think manmade foods will be a bigger part of our future meals? I'm Kojo Nnamdi.

NNAMDIWe're having a conversation about in vitro meat with Michael Specter. He's a staff writer at the New Yorker. He often covers science, technology, and public health. Michael Specter is the author of the book "Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet, and Threatens Our Lives." He joins us from NPR's Bryant Park Studios. Joining us by phone from the Netherlands is Mark Post. He's a professor of vascular physiology at Maastricht University in the Netherlands where he working on the development of in vitro meat.

NNAMDIMark Post, the meat most of us eat is mainly made up of muscle tissue, and muscle needs, well, exercise to build up mass. How do you make that happen in a lab?

POSTRight. Well, fortunately, D cells love exercise, so they actually do some of this themselves. By the way we culture them between anchor points, the future tendons if you like, the develop tension and actually also contractions. So they start to develop spontaneous contractions in the lab, and they develop tension in between those tendons, and that boosts that protein synthesis quite a bit. In addition, we can also stimulate them, for instance with electrical stimulation and that also boosts even further the protein production, but is course is less energy efficient. So fortunately, they do a lot of it by themselves.

NNAMDIAnd Michael, a lot of people's first reaction as you heard, to the idea of eating meat from a lab can be summed up in one syllable, ick. Is it clear whether there's a market for lab-made meat?

SPECTERWell, I think, again, the initial response is ick, yuck, or something like that.

NNAMDIBut once they get past that factor, they want to know what does it taste like, I guess.

SPECTERYeah. And I, you know, I think we're not there yet, and I think it's really important that the guys in the Netherlands are doing a proof of principle. So you can, you know, when I wrote the story, every single person I knew before it came out said, what did it taste like, and I had to say, I saw basically microscopic amounts of it. So to be able to make a hamburger and make it real, I think will be meaningful to people.

SPECTERThere will be a market if the stuff is healthy, tasty, and financially viable. You got to remember on the yuck factor, a lot of people don't know how the animals they eat are killed. It's a pretty significantly yucky -- I mean, Ingrid mentioned this in the clip you played, but anyone who's ever been to a slaughterhouse or a factory farm is gonna have a tough time telling me that that's less yucky than this.

NNAMDIWell, Jonathan emails to ask, "Well, how will these meats get their flavor?"

SPECTERYou know you should ask Mark. There's a whole industry of taste and flavor, and I don't think that's a very difficult part of this, but Mark knows...

NNAMDIMark Post, go ahead, please.

POSTRight. Right. It's not exactly my field, but we have, of course, food technologists on board that are able to look at different aspects of meat, not only flavor, but also texture and the way it reacts to heating and that sort of thing. But the flavor of course is a crucial aspect, and that not only comes from the muscle but also from the fat as we all have experienced. So we are currently working under the assumption that if we grow these muscle tissues and these fat tissues under conditions that replicate their eventual looks and color and texture, that the taste will also come with it.

POSTIt's a matter of the right protein content, iron, aromatics that are dissolved in the fat of the tissue, and it's basically relying on the innate biochemistry of those cells.

NNAMDIOn to Victor in Frederick, Md. Victor, you're on the air. Go ahead, please.

VICTORThank you, Kojo. Thank you for taking my call. I really like the concept of being able to grow meat in the lab as an alternative for meat, but I was curious, I've worked in the sciences for many years. Many cell lines require serum from different animals to be grown in, many times, fetal bovine serum, but for some vaccine studies, you have to use serum-free media. And I was just curious if Mark could address whether these cultures are serum-free, or do they still require animal serum for growth as the safety concern?

NNAMDIMark Post?

POSTRight. Well, you are perfectly right, and right now we are basically still using sort of standard techniques to grow cells, and so yes. We are still using fetal bovine serum to grow them and that's why I'm saying, you know, after this proof of concept, we need to do a lot of work. And an important part of it is get rid of the animal products that are still in the culture medium, and to replace them with other substitutes, and that has been done. The technology is out there, it's just never done at a scale that would be required for a meat production system.

NNAMDIThank you very much for your call, Victor. Here is Chad in Washington D.C. Chad, you're on the air. Go ahead, please.

CHADHi Kojo. Thanks for taking my call. The comment that I want to make is just that it seems like a lot of the criticism that's coming from the callers is based on this sort of belief that natural is innately better than artificial, and to me it sounds a lot like the paranoid colonel from the movie "How I Learned to Stop Worrying and Love the Bomb," Dr. Strangelove, and his fear that putting fluoride in water was a secret government plot and would turn the United States into a communist weakling power.

CHADSo for me, a lot of these fears seem irrational, and that's not to say that there aren't legitimate concerns that can come up for example, using biotics in meat right now has created a lot of antibiotic resistances, so there are things that we can't necessarily foresee that might be a problem, but that doesn't mean that out of hand anything artificial is worse than its natural counterpart. And with that, I'll take my comments off the air.

NNAMDIWell, thanks for quoting one of my favorite movies. Care to comment on that, Michael Specter?

SPECTERWell, I'm obviously 1,006 percent in agreement with him. I wrote a book about this. The idea that somehow natural is great and artificial is terrible is silly, but it also doesn't mean that we're gonna sail through this, and I think we actually have an opportunity that we blew with genetically engineered foods, which is to have these kind of discussions before it's out there so people know what they are getting, know what they may or may not be willing to eat.

SPECTERI don't see a time in the rich west where, you know, all the animals will be replaced by this kind of meat, but I, again, think any strides we can take to producing healthier protein in greater quantities without the waste of environmental spoilage, is fantastic.

NNAMDIWell, Hunter in College Park has a question along the lines of safety for you, Mark. Hunter, you're on the air. Go ahead, please.

HUNTERYeah. Hey, Kojo. I just want to say that I agree a lot with what your guests are saying that this technology is not necessarily harmful, but we do also know that cancer is caused by the damage of DNA and as our cells replicate, that the damage also becomes replicated. So I just wanted to know if there's any testing done with the experiments Mark's doing with testing the DNA and making sure that these cells are not damaged over time.

NNAMDIMark Post?

POSTRight. Right. Excellent point. So for the general sort of safety of our food there is an optimal DNA protein ration, and there is always the danger if you use fast replicating cells that they become genetically unstable and produce more DNA per cell. So that's what needs to be checked. We are checking that right now at smaller scales, and you would need to check it sort of sample wise during a production process.

POSTOne of the -- this is actually also one of the reasons why I personally prefer to use the skeletal-muscle-derived stem cell because it has only a limited number of replications. It's a lot, but it's limited. So you don't rely on a very small source of forever-replicating cells, and you keep the checks and balances that are in place in animal bodies. For the stem cell production, you keep that actually -- that part in the animals.

NNAMDIThank you so much for your call, Hunter. Lisa in Washington D.C. also has a question about testing. Lisa, you're on the air. Go ahead, please.

LISAYes. This is Lisa. Okay, hi.

NNAMDIHi, Lisa.

LISAYou may have talked about it already, and I heard you mentioning protein, but I think meat has other nutrients like B12. I don't really even know what other nutrients, and it seems like maybe that blood part that you mentioned, this method doesn't include blood vessels, may play a part in how B12 is produced or how other nutrients are produced, and it just seems complicated, all the different things that go into making meat what it is, and I'm asking about that.

NNAMDIHave you been able to test the levels of nutrients in lab meat, Mark?

POSTWell, we have done some of that, but by far not enough yet. And of course the B12 issue comes up quite often. And B12 it gets a little technical, but the B12 biochemistry is actually very interesting and can be -- but the bottom line is that you can add it relatively easily to the meat if you want to.

NNAMDIOkay. Thank you very much for your call, Lisa. We got a tweet from Matt who says the potential for good with lab-grown meat from alleviating hunger to cutting carbon to culinary creations is breathtaking. While there's a lot of excitement among scientists and clearly in Matt's case, working on in vitro meat, Michael, there are others who caution against false hope and buying into hype. How realistic is that I'll be able to buy in vitro meat say in the next decade?

SPECTERProbably not so realistic. I think it is really important to be measured about these things. As a long-time science writer, the press, including no-doubt me, have cured many diseases that ended up not being cured because they were cured in a lab or with mice or in a test tube. So, you know, we're far from buying this food in a supermarket, but it's really important to know that we can move in that direction and that there will be discussions and there will be safety checks and balances. This food's not just gonna dumped on the market.

SPECTERIt would have to be approved by places like the FDA and the USDA, and you also always have to remember the risks of the other side. The risks of eating animal fat we know, because we're dying of it in huge numbers.

NNAMDIWhich brings me to finally this email we got from Ben in Silver Spring who said, "Will this mean we could eat all sorts of meat that we would never consider now through this process, for example, panda burgers? This seems to completely change the calculus of the morality of meat, because it removes death from the equation." Michael Specter? You got about 20 seconds.

SPECTERYeah. I think he's right. I think the morality issue is a big one, and it's an exciting one, and it's an opportunity to look in a direction that we've never even been able to contemplate before.

NNAMDIMichael Specter, he's a staff writer at the New Yorker. He often covers science, technology, and public health. He's also the author of "Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet, and Threatens Our Lives." Michael Specter, thank you for joining us.

SPECTERMy pleasure.

NNAMDIAnd Mark Post is a professor of vascular physiology at Maastricht University in the Netherlands. He's working on the development of in vitro meat. Mark Post, thank you for joining us.

POSTYou're very welcome.

NNAMDIAnd thank you all for listening. I'm Kojo Nnamdi.