In defence of healthy mistrust

Does panic over a non-existent shooting in Oxford Street mean we can’t trust Twitter to tell us the

It's the kind of thing that Twitter excels at, even when it's got the wrong end of the stick. Within minutes, news of a "shooting in Oxford Street" created a huge amount of noise and a flurry of tweets. Understandably panicky Londoners told each other to stay indoors and be safe. But there was no shooting, and it was a misunderstanding that seems to have been based partly on a police training exercise and partly on a tweet about a fashion shoot.

Does that mean we can't trust Twitter to tell us what's going on? Tom Rayner, a Sky News producer, said:

The lessons from this morning's non-incident are clear: for the police, they now have to be far more careful managing and protecting information, and more proactive in quelling rumours when they emerge.

For journalists, the advent of Twitter has made the importance of checking and verifying stories even greater.

Tom's colleagues at Sky News know this all too well, having cited a joke tweet from the spoof "Daily Mail reporter" account as evidence that Vince Cable was going to resign a few weeks ago. As we now know, Cable is still very much in his job, but it goes to show that a single tweeter may not be a perfect source of information, and even a mass of panicky tweeters chirping away can lead you in the wrong direction. In the quest to be first to break the news, it's easy to see what you want to see.

On the other hand, getting information from the Twittersphere isn't necessarily a bad thing. At the height of the recent student protests, it was easy for news to focus on safe, official information from the police which gave only one side of the story, while there was a mass of contradictory information coming from inside the police kettles. Who to believe? Journalists are taught to give more weight to "official" sources like the police – or at least to know that if a police source says something untrue, you won't get in as much trouble for printing it – which can lead to a slightly skewed version of events appearing in the early stages.

Official sources aren't without their drawbacks, though, when it comes to this kind of thing. Met Police commander Bob Broadhurst told MPs that there were no plain-clothes police at the G20 protests; we now know this not to be the case. An official, trusted voice can drown out the many eyewitnesses who may have the opposing view.

Perhaps the best way to proceed is to treat official sources and anonymous tweeters with equal cynicism. At the moment, a man in a suit and tie, or a uniform, sitting behind a microphone or carving out a press release is always going to be believed more than a funny avatar and fewer than 140 characters of text. Which is understandable. But that doesn't mean we should always trust the suit and tie more; perhaps an equal amount of healthy mistrust might be appropriate.

Twitter does get it wrong sometimes, and can be misleading; but it adds to an environment in which readers find themselves constantly challenging the veracity of sources, tweets or statements, as well as comparing the official version of events to what people on the ground are saying. And that is no bad thing.

Patrolling the murkier waters of the mainstream media
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.