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?"

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.

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

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 19 August 2013 issue of the New Statesman, Why aren’t young people working

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.