THERE are few modern Scottish symbols greater than Barr’s Irn-Bru. Oor Wullie and the Broons, perhaps;Desperate Dan with his magnificent statue in central Dundee; maybe a Tunnock’s Tea Cake or two. We take a sometimes tongue-in-cheek pride in the weirdly orange concoction Scots have loved as a hangover cure. It remains the staple of workmen’s lunch-breaks and children’s packed lunches.

Irn-Bru is so much a part of the comic lexicon of “wha’s like us” Scotland – the one imagined by TV advertising – that it seems churlish, almost unpatriotic, to question its validity. But Scotland’s “favourite drink”, the one “made from girders”, has a questionable role.

Today in Scotland an estimated 276,000 people live with diabetes, with a staggering further 500,000 at risk. Eighty per cent have Type 2, a largely preventable disease approaching an epidemic. Diabetes costs the Scottish economy £2.37 billion a year, a sum predicted to get much worse. Apart from the £90 million on medication, this covers complications such as stroke, cardiovascular disease and lower limb amputation. NHS Scotland has an excellent record in helping people manage the disease but it faces being swamped as numbers rise.

We know the causes: obesity, lack of regular exercise and unbalanced diet. Processed foods and soft drinks are contributors. Unfettered, sugary soft drinks could become the tobacco of the future; products we know will harm us yet remain legal and available.

Irn-Bru maker AG Barr chose its annual results – profits up, sales down – to announce job losses, the implied blame laid with the coming sugar tax. On closer reading, the cause is a fierce ongoing price war. Many ingredients are priced in dollars and euros and a weak pound means dearer raw materials. The sugar tax, coming in 2018, was “a punitive and unnecessary distortion to competition in the UK market which will be very complex, expensive and difficult to implement,” the company said.

Clinicians and food activists beg to differ. The sugar tax is a small important step towards cutting the massive amounts of sugar imbibed by children for generations. The NHS’s recommended level of added sugar per day is 30g for adults. Contrast that with the legalese of the average drinks label and you will find a 330ml can of “full fat” Irn Bru contains 38g of sugar. The traditional 750ml bottle, favoured by “morning-after” adherents, contains more than double that NHS recommended daily intake. No wonder it’s a hangover cure, with so much sugar mixed amongst the 30-odd ingredients of the famed “secret recipe”.

The Barr statement revealed that it may well avoid the sugar tax completely. Like many competitors, it is racing to make its products sugar-free before the deadline. Given what we have known about sugar, why has it taken so long? The answer, of course, is that the Treasury has finally forced soft-drinks manufacturers into it. They have demonstrated that they will act on a major health issue only when forced to do so by taxation or the law. That applies to one of our much-loved companies as it does to anyone else.