Here comes the science bit


Yes, you can make a burger out of human stem cells - but you probably wouldn't want to

After the success of the test-tube burger, Michael Brooks answers the question on everyone in the NS offices lips: "Why not make burgers from human stem cells?"

Man eating burger.
You are what you eat - or at least you might be. Photograph: Getty Images.

Sometimes the NS’s offices resound with provocative questions. Last week, it was: “Why not make burgers from human stem cells?”

This is not as ridiculous as it might first seem. It would be the pinnacle of ethical carnivorous living, the only way you could eat prime meat with the full, informed consent of the donor.

It wouldn’t be cheap. The price of a burger cultured from human cells would make the €250,000 feed, created by the Maastricht University researcher Mark Post and formally presented on 5 August, look like a bargain. Human stem-cell culture for medical research is done under the most onerous safety restrictions and following strict protocols. Culturing human cells for human consumption would be just as onerous (and thus expensive) as it is for medical research because we would have to make sure there was no chance the cells could become infected by viruses or bacteria.

Eating other animals is safer simply because the pathogens that make them ill do not necessarily make humans ill. Eat your own kind and you risk unleashing all kinds of hell. That was what the BSE crisis was all about. Ingestion of ground-up cattle brains in cheap cattle feed led to an epidemic of the bovine disease. A similar phenomenon was discovered in human beings in the 1950s. The Fore people of Papua New Guinea were eating their deceased relatives in order to absorb their strength and other qualities. Enormous numbers of them contracted kuru, a disease related to BSE, which killed hundreds of them.

Yet many more Fore women and children died of kuru than men (to the point where the women accused the men of using witchcraft to destroy them). Usually, in the traditional funeral rites, the men were given the prime cuts to eat –muscle tissue –while the women and children got the brains and organs, which harboured disease in far more virulent measure. The Fore men were largely fine, so you could argue that cannibalism is not necessarily a health hazard: it’s eating the wrong bits that kills you.

The real show-stopper for the human stem-cell burger is the bit that most of the media coverage glossed over. Growing those stem cells is not a matter of scattering them in a bed of organic grass. The cells are grown in a cocktail of antibiotics and “fetal bovine serum”. This is blood drawn from foetuses that have been removed from slaughtered pregnant cows.

At about £160 (or three cow foetuses, depending on how you want to look at it) a litre, this is the most expensive part of the whole process. It is also the most distasteful. Experiencing poor mouthfeel from a burger is one thing. Knowing a cow foetus has had its heart punctured and sucked dry in order to grow the meat is quite another.

Medical researchers get through roughly half a million litres of fetal bovine serum a year because its hormones and growth factors are so essential to stem-cell growth. There are problems with it, though. The chemicals it contains can skew the outcome of experiments. In addition, the serum is extracted in a slaughterhouse, with no anaesthetic, and research shows that the foetus probably feels pain or discomfort.

The good news is researchers are looking for replacements. Human umbilical-cord blood plasma, for instance, looks like a good candidate. But considering how few of us out there would stomach a dish containing human placenta, you could bet that there’s not much of a market for any of this.

So, yes, you can have a human burger. But we suspect you don’t want one. Not really.