Musing 2: dietary fads v. the truth

A recent article from Dr Mark Porter in The Times explains why so many people are unnecessarily pursuing (and, worse, inflicting on others) misinformed dietary regimes.This one on gluten intolerance is illuminating.

“When I entered general practice in the 1990s, gluten-free products were largely confined to health food shops and the dustier shelves of pharmacies. Today they often warrant their own aisle in the supermarket and last weekend’s product recall (amid fears that some foods were contaminated with gluten) was headline news. How times change.

Just mentioning gluten — a type of protein found in wheat, barley and rye — can induce a wry smile from a GP, thanks to one of the great paradoxes of 21st-century medicine. On the one hand, probably at least 250,000 people in the UK are unaware that they have a serious sensitivity (coeliac disease), and suffer unnecessarily with such symptoms as fatigue, skin rashes, upset stomach, and malabsorption. Meanwhile millions pursue a gluten-free diet when they don’t need to, simply because it is a fad and they’ve been told it will help with everything from bloating to middle-age spread. So forgive my cynicism if I reassure the likes of Asda, Sainsbury’s, Waitrose and Teseo that while any contaminated gluten-free products may have caused big problems for some customers, the vast majority who purchased them probably wouldn’t have known any different had the retailers kept schtum. As for all those who say they feel better when they cut out gluten, despite what their doctor advises, could they have a milder version of coeliac disease — so called non-coeliac gluten sensitivity (NCGS)?

Well, not according to the latest research from Australia, which suggests that no such condition exists. Just because you feel healthier by not eating bread doesn’t make you gluten intolerant. I remain to be convinced that it is anything to do with the gluten, or lack of it, in their diets. Indeed, I’d like to propose an alternative regimen for those who consider themselves gluten- sensitive but don’t have coeliac disease. I accept that otherwise healthy people can lose weight and/or experience less bloating or loose bowels after cutting out gluten, but there are a couple of reasons that might happen.

First, gluten is most commonly found in carbohydrate- based foods such as bread, cake, pizza, pasta and biscuits. You can buy gluten- free versions of all these, but they tend not to be as nice, so those who make the switch often end up eating less carbohydrate in total and consume fewer calories as a result. What about the impact on their bowels? According to the Australian research, any benefits from cutting out gluten may be due to a) the placebo effect, and b) a change in the type of fibre eaten, in particular consumption of carbohydrates known as Fodmaps (fermentable oligo-, di-, mono¬saccharides and polyols), which affect intestinal fluid content and are fermented to produce intestinal gas. Avoiding foods rich in Fodmaps — such as garlic, onions, most wheat- containing products such as bread and cereals, and fruits such as apples and raisins — makes much more sense than a gluten-free diet for people who don’t have proven coeliac disease. It is likely to be more effective, cheaper and easier to stick to.

Fodmaps may not trip off the tongue as easily as gluten-free but the low-Fodmap diet is the rising star of the gastroenterological firmament, particularly in clinics specialising in irritable bowel syndrome (IBS). There is plenty of information online but the diet works best under the direction of a dietician, although access can be an issue on the NHS. And, to avoid confusion, a low-Fodmaps diet is not a substitute for going gluten-free if you have proven coeliac disease.

How to spot symptoms of coeliac disease
• The symptoms of coeliac disease vary with age. Clues in children include diarrhoea, lethargy, distended stomachs and poor growth.
• Adults often complain of IBS- related symptoms such as bloating and loose bowels. Stools may be difficult to flush and malabsorption can result in weight loss or iron and vitamin B12 deficiency.
• Lack of energy is another common complaint, and occasionally gluten can trigger an itchy rash (dermatitis herpetiformis).
• A blood test can spot the disease but only in people eating gluten.
• For more detailed information on the diagnosis and management of coeliac disease visit coeliac.org.uk