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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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I can’t follow Marie Kondo's advice – even an empty Wotsits packet “sparks joy” in me

I thought I’d give her loopy, OCD theories a go, but when I held up an empty Wotsits bag I was suffused with so many happy memories of the time we’d spent together that I couldn’t bear to throw it away.

I have been brooding lately on the Japanese tidying freak Marie Kondo. (I forgot her name so I typed “Japanese tidying freak” into Google, and it was a great help.) The “Japanese” bit is excusable in this context, and explains a bit, as I gather Japan is more on the case with the whole “being tidy” thing than Britain, but still.

Apart from telling us that we need to take an enormous amount of care, to the point where we perform origami when we fold our underpants, which is pretty much where she lost me, she advises us to throw away anything that does not, when you hold it, “spark joy”. Perhaps I have too much joy in my life. I thought I’d give her loopy, OCD theories a go, but when I held up an empty Wotsits bag I was suffused with so many happy memories of the time we’d spent together that I couldn’t bear to throw it away.

After a while I gave up on this because I was getting a bit too happy with all the memories, so then I thought to myself, about her: “This is someone who isn’t getting laid enough,” and then I decided that was a crude and ungallant thought, and besides, who am I to wag the finger? At least if she invites someone to her bedroom no one is going to run screaming from it, as they would if I invited anyone to my boudoir. (Etym: from the French “bouder”, to sulk. How very apt in my case.) Marie Kondo – should bizarre circumstance ever conspire to bring her to the threshold – would run screaming from the Hovel before she’d even alighted the stairs from the front door.

I contemplate my bedroom. As I write, the cleaning lady is in it. To say that I have to spend half an hour cleaning out empty Wotsits packets, and indeed wotnot, before I let her in there should give you some idea of how shameful it has got. And even then I have to pay her to do so.

A girlfriend who used to be referred to often in these pages, though I think the term should be a rather less flippant one than “girlfriend”, managed to get round my natural messiness problem by inventing a game called “keep or chuck”.

She even made up a theme song for it, to the tune from the old Spiderman TV show. She would show me some object, which was not really rubbish, but usually a book (it may not surprise you to learn that it is the piles of books that cause most of the clutter here), and say, “Keep or chuck?” in the manner of a high-speed game show host. At one point I vacillated and so she then pointed at herself and said, “Keep or chuck?” I got the message.

These days the chances of a woman getting into the bedroom are remote. For one thing, you can’t just walk down the street and whistle for one much as one would hail a cab, although my daughter is often baffled by my ability to attract females, and suspects I have some kind of “mind ray”. Well, if I ever did it’s on the blink now, and not only that – right now, I’m not even particularly bothered that it’s on the blink. Because, for another thing, I would frankly not care to inflict myself upon anyone else at the moment.

It was all a bit of a giggle eight years ago, when I was wheeled out of the family home and left to my own devices. Of course, when I say “a bit of a giggle”, I mean “terrifying and miserable”, but I had rather fewer miles on the clock than I do now, and a man can, I think, get away with a little bit more scampish behaviour, and entertain a few more illusions about the future and his own plausibility as a character, when he is squarely in his mid-forties than when he is approaching, at speed, his middle fifties.

Death has rather a lot to do with it, I suppose. I had not actually seen, or touched, a dead body until I saw, and touched, my own father’s a few weeks ago. That’s what turns an abstract into a concrete reality. You finally put that to one side and gird up your loins – and then bloody David Bowie snuffs it, and you find yourself watching the videos for “Blackstar” and “Lazarus” over and over again, and reach the inescapable conclusion that death is not only incredibly unpleasant, it is also remorseless and very much nearer than you think.

And would you, dear reader, want to be involved with anyone who kept thinking along those lines? I mean, even if he learned how to fold his undercrackers into an upright cylinder, like a napkin at a fancy restaurant, before putting them in his drawer? When he doesn’t even have a drawer?

Nicholas Lezard is a literary critic for the Guardian and also writes for the Independent. He writes the Down and Out in London column for the New Statesman.

This article first appeared in the 05 February 2015 issue of the New Statesman, Putin's war