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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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Let's face it: supporting Spurs is basically a form of charity

Now, for my biggest donation yet . . .

I gazed in awe at the new stadium, the future home of Spurs, wondering where my treasures will go. It is going to be one of the architectural wonders of the modern world (football stadia division), yet at the same time it seems ancient, archaic, a Roman ruin, very much like an amphitheatre I once saw in Croatia. It’s at the stage in a new construction when you can see all the bones and none of the flesh, with huge tiers soaring up into the sky. You can’t tell if it’s going or coming, a past perfect ruin or a perfect future model.

It has been so annoying at White Hart Lane this past year or so, having to walk round walkways and under awnings and dodge fences and hoardings, losing all sense of direction. Millions of pounds were being poured into what appeared to be a hole in the ground. The new stadium will replace part of one end of the present one, which was built in 1898. It has been hard not to be unaware of what’s going on, continually asking ourselves, as we take our seats: did the earth move for you?

Now, at long last, you can see what will be there, when it emerges from the scaffolding in another year. Awesome, of course. And, har, har, it will hold more people than Arsenal’s new home by 1,000 (61,000, as opposed to the puny Emirates, with only 60,000). At each home game, I am thinking about the future, wondering how my treasures will fare: will they be happy there?

No, I don’t mean Harry Kane, Danny Rose and Kyle Walker – local as well as national treasures. Not many Prem teams these days can boast quite as many English persons in their ranks. I mean my treasures, stuff wot I have been collecting these past 50 years.

About ten years ago, I went to a shareholders’ meeting at White Hart Lane when the embryonic plans for the new stadium were being announced. I stood up when questions were called for and asked the chairman, Daniel Levy, about having a museum in the new stadium. I told him that Man United had made £1m the previous year from their museum. Surely Spurs should make room for one in the brave new mega-stadium – to show off our long and proud history, delight the fans and all those interested in football history and make a few bob.

He mumbled something – fluent enough, as he did go to Cambridge – but gave nothing away, like the PM caught at Prime Minister’s Questions with an unexpected question.

But now it is going to happen. The people who are designing the museum are coming from Manchester to look at my treasures. They asked for a list but I said, “No chance.” I must have 2,000 items of Spurs memorabilia. I could be dead by the time I finish listing them. They’ll have to see them, in the flesh, and then they’ll be free to take away whatever they might consider worth having in the new museum.

I’m awfully kind that way, partly because I have always looked on supporting Spurs as a form of charity. You don’t expect any reward. Nor could you expect a great deal of pleasure, these past few decades, and certainly not the other day at Liverpool when they were shite. But you do want to help them, poor things.

I have been downsizing since my wife died, and since we sold our Loweswater house, and I’m now clearing out some of my treasures. I’ve donated a very rare Wordsworth book to Dove Cottage, five letters from Beatrix Potter to the Armitt Library in Ambleside, and handwritten Beatles lyrics to the British Library. If Beckham and I don’t get a knighthood in the next honours list, I will be spitting.

My Spurs stuff includes programmes going back to 1910, plus recent stuff like the Opus book, that monster publication, about the size of a black cab. Limited editions cost £8,000 a copy in 2007. I got mine free, as I did the introduction and loaned them photographs. I will be glad to get rid of it. It’s blocking the light in my room.

Perhaps, depending on what they want, and they might take nothing, I will ask for a small pourboire in return. Two free tickets in the new stadium. For life. Or longer . . . 

Hunter Davies is a journalist, broadcaster and profilic author perhaps best known for writing about the Beatles. He is an ardent Tottenham fan and writes a regular column on football for the New Statesman.

This article first appeared in the 16 February 2017 issue of the New Statesman, The New Times