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Got a cold? Eat caterpillars

Why medinical zinc is not all it's cracked up to be.

How’s this for impact? At the end of January, a research group in Manchester published a paper on the essential role of zinc in the human immune system. A week later, the price of zinc rose on the international metals markets after its longest slump in 25 years.

Amazing? Of course not. These are two entirely unrelated events. But it’s the ability to separate coincidence from causality that allows us to distinguish old wives’ tales from useful information.

Zinc has been in medical use since at least the 2nd century BC. A set of pills found in the remains of a ship wrecked off the Tuscan coast in 140BC are 75 per cent zinc. They were almost certainly used to treat eye and skin disorders, a practice documented by the Roman polymath Pliny in the 1st century AD.

Zinc is still used for this purpose. It has antiseptic and antiviral properties, which is why it is often embedded in dressings for wounds. What’s more, anecdotal evidence has long suggested that taking zinc supplements helps fight the common cold. But anecdotal evidence isn’t the most trustworthy: sometimes it sees cause and effect where there is none.

Even individual studies haven’t been enough to give us the answer; depending on how they are carried out, they can produce conflicting results. Fortunately, we’ve developed even more sophisticated techniques: dissection, analysis and pooling of the scientific studies themselves. This has allowed us to draw a firm and reliable conclusion. In the case of zinc, it’s this: take at least 75mg a day and “there is a significant reduction in the duration of cold”, according to a gold-standard Cochrane Review, which looks at primary research in health care. Ancient wisdom, in this case, has some validity.

What the ancients didn’t know is the mechanism involved. Zinc deficiency, it turns out, causes more than 3,000 types of protein in the body to function inefficiently or not at all. The body responds to this as stress, causing the immune system to leap into action. Specifically, according to researchers at Manchester University, zinc deficiency unleashes a molecule called interleukin-1-beta. This is part of the armoury of the immune system. The trouble is that, in the absence of any infection to clear, firing the immune response’s weaponry just causes damage.

The zinc deficiency, as the researchers point out, could easily be resolved using dietary supplements. And this increased medical use of zinc could have an economic impact.

Not, it has to be said, in the metals markets, where the rising price of zinc is linked to China’s construction boom. But zinc use for medical purposes could be worth about $25bn a year in the US alone. That is the estimated annual impact of common colds, in terms of lost productivity. The Cochrane Review has found that taking zinc supplements for at least five months can reduce that. It certainly reduces school absences and the prescription of antibiotics for children with the common cold.

Because colds are caused by a virus, antibiotics do nothing for sufferers, yet doctors prescribe them as a placebo to get worried parents out of their surgery. So zinc supplementation also slows the spread of antibiotic resistance. Here’s a final tip in case the price of zinc lozenges skyrockets: a daily 100g of cooked caterpillars contains all the zinc you need.

You’re welcome.
 

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 February 2014 issue of the New Statesman, The Space Issue

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The boy who lies: what the Daily Prophet can teach us about fake news

The students at Hogwarts are living in an echo chamber of secrets.

They can make objects levitate, conjure up spirit animals and harness the power of invisibility. But perhaps the strangest thing about the witches and wizards of the Harry Potter universe is that despite all their magic, they still rely on old-fashioned print media for their news.

Although the Daily Prophet bills itself as “the wizarding world’s beguiling broadsheet of choice”, the reality is that its readers have no choice at all. Wizards don’t have their own television network – the risk of muggles accidentally tuning in was deemed too high – they don’t generally use the internet, and rival publications are virtually non-existent. (No, Witch Weekly doesn’t count.)

JK Rowling clearly sought to satirise the press in her portrayal of the Prophet, particularly through its poisonous celebrity journalist Rita Skeeter and her tenuous relationship with the truth. And in doing so, the author highlighted a phenomenon that has since become embedded within the muggle political landscape – fake news, and how quickly it can spread.

In the run-up to the recent French presidential election, an Oxford University study found that up to a quarter of related political stories shared on Twitter were fake – or at least passing off “ideologically extreme” opinion as fact.

While they don’t have social media at Hogwarts – probably for the better, despite the countless Instagram opportunities that would come with living in an enchanted castle – made-up stories travel fast by word of mouth (or owl.) The students are so insulated from the outside world, the house system often immersing them in an echo chamber of their peers, they frequently have no way to fact-check rumours and form rational opinions about current events.

When the Ministry of Magic flatly refuses to believe that Voldemort has returned – and uses the Prophet to smear Harry and Dumbledore – most students and their parents have no choice but to believe it. “ALL IS WELL”, the Prophet’s front page proclaims, asking pointedly whether Harry is now “The boy who lies?”

While Harry eventually gets his side of the story published, it’s in The Quibbler – a somewhat niche magazine that’s not exactly light on conspiracy theories – and written by Skeeter. He is telling the truth – but how is anyone to really know, given both the questionable magazine and Skeeter’s track record?

After Voldemort’s followers take over the Ministry, the Prophet stops reporting deaths the Death Eaters are responsible for and starts printing more fake stories – including a claim that muggle-born wizards steal their magical powers from pure-bloods.

In response, Harry and his allies turn to their other meagre sources such as The Quibbler and Potterwatch, an underground pirate radio show that requires a password to listen – useful to some, but not exactly open and accessible journalism.

Rowling is clear that Harry’s celebrity makes it hard for him to fit in at Hogwarts, with fellow students often resenting his special status. Do so many believe the Prophet’s smear campaign because they were unconsciously (or actively) looking forward to his downfall?

We are certainly more likely to believe fake news when it confirms our personal biases, regardless of how intelligently or critically we think we look at the world. Could this explain why, at the start of last week, thousands of social media users gleefully retweeted a Daily Mail front page calling on Theresa May to step down that was blatantly a poorly-edited fake?

The non-stop Hogwarts rumour mill illustrates the damage that a dearth of reliable sources of information can cause to public debate. But at the other end of the scale, the saturation of news on the muggle internet means it can also be hugely challenging to separate fact from fiction.

No one is totally free from bias – even those people or sources whose opinions we share. In this world of alternative facts, it is crucial to remember that all stories are presented in a certain way for a reason – whether that’s to advance a political argument, reaffirm and promote the writer’s own worldview, or stop an inconvenient teenage wizard from interfering with the Ministry of Magic’s plans.

Now read the other articles included in the New Statesman’s Harry Potter Week.

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