Battle of the wheatfield

Rational discussion of genetically modified crops is beyond us

Let me say from the outset, I think the experiment at Rothamsted should go ahead without interference from campaigners opposed to the genetic modification of crops. But I doubt it will.

The experiment looks at whether wheat could repel aphids by expressing genes that give off a “panic” pheromone that aphids use to warn of danger. These genes, which have been synthesised from chemicals in a lab, have been woven into the wheat’s genome.

It’s a brilliant strategy, well worth trying. If it works, you wouldn’t need to spray this wheat with insecticides. However, this very sensible experiment is under attack.
 
Anti-GM campaigners have announced they will arrive en masse to destroy the experiment on May 27th. The scientists have released a video pleading with the protestors not to trample years of their work. It’s unlikely to have any traction, though. This isn’t personal; it’s simply that GM scientists have not yet earned the right to do their research uncontested.
 
In many people’s minds, science is still scary – especially when it tinkers with nature. Watch this one-minute of video about Rachel Carson’s call for a ban on DDT in 1963, and see if the scientist doesn’t make you shiver a little bit.
 
This is still the tone many people hear when they hear scientists talking. People are, in general, all in favour of the products of science. But they also know there’s no such thing as a free lunch. Advances and comforts come at a cost – and people want to know what the cost might be before they give unqualified support to a programme of research.
 
That leaves scientists with two choices. They either try to win a battle for hearts and minds before they press ahead with experiments – those who mix human and animal biology are engaged with this right now. The alternative is to ignore public concerns, raise private funding and do semi-secret experiments, then present the public with a fait accompli that they like – such as Louise Brown, the world’s first test tube baby.
 
It seems to be too late for GM researchers to do either. The battle for hearts and minds is already lost: there is a pervasive belief that, without extreme caution, genetic modifications are likely to spread beyond experimental boundaries and might have unintended adverse effects on natural ecosystems. And Monsanto scuppered any future acceptance of the private route by their early attempts to create themselves a lucrative market at the expense of farmers in the developing world.
 
We have never managed to hold a properly informed public discussion about genetically modified organisms, and thanks to the subject’s history, that discussion might now be impossible. Which means extremist anti-GM groups will continue to thwart even the most laudable scientific efforts while the public shrugs and wonders if that isn’t the best thing for everyone in the long run.
An ultralight helicopter hovers above a field where Greenpeace activists wrote the message 'NO GMO'. 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.

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.