From the egg regime of 16th-century Venetian Luigi Cornaro to Lord Byron’s obsession with the fat-busting benefits of vinegar potatoes, there’s nothing new about the celebrity-endorsed diet.
These days, of course, the food fad rolling the biggest bucks is gluten-free, with everyone from Gwyneth Paltrow to Novak Djokovic proclaiming the health-imbuing benefits of life without the evil G.
Most recently, former Dragon’s Den mogul Duncan Bannatyne called on his 730,000 Twitter followers to copy his lead and ditch gluten to “double” their energy and lose belly fat.
Statistics show that Coeliac disease – a lifelong autoimmune disorder where ingestion of gluten causes potentially life-changing damage to the small intestine – affects one per cent of the population. A recent US survey suggested Non Coeliac Gluten Sensitivity (NCGS) afflicts 0.5 per cent of the population.
Up to one in three people don’t eat gluten
Yet around eight per cent of Brits now try to follow a gluten-free diet, which means cutting out wheat and related grains, including barley and rye. In the US the figure is as high as one in three.
So what is the truth about gluten? Are we justified in blaming it for the ills of a generation? Is Miley Cyrus right when she tweets “Gluten is crappppp”? We asked the experts for the truth about the five biggest gluten-free myths.
The five biggest gluten-free myths
1. Our bodies can’t digest gluten properly
Wheat’s introduction into the British diet from south-east Turkey 5,000 years ago is taken to show that the gluten-containing grain is not a ‘natural’ source of nutrition.
David Perlmutter, author of Grain Brain, insists: “As many as 40 per cent of us can’t properly process gluten, and the remaining 60 per cent could be in harm’s way.”
But Dr Isabel Skypala, consultant allergy dietitian at the Royal Brompton & Harefield NHS Foundation Trust, says: “You can’t take a group of people that have problems with wheat and say that can apply to a healthy population.
“There is nothing to suggest that people can’t tolerate, digest or absorb gluten.”
Rather, she adds, “from the perspective of a healthy diet wheat is a staple food for us”, containing much-needed fibre, B vitamins and minerals.
2. Modern wheat is wildly different to traditional varieties
American cardiologist William Davis, author of controversial bestseller Wheat Belly, claims “genetic research in the 60s and 70s” led to the inclusion of an unnatural protein in our ‘modern wheat’ called gliadin (a component of gluten), which “stimulates appetite”, so leading to greater consumption than ever before.
But, according to wheat research scientist Professor Peter Shewry: “The wheat we eat hasn’t changed much in the past 150 years.”
While yield has increased – from about three tones per hectare in the UK to eight tonnes now – he says: “When you increase the yield the crop generally has bigger seed containing more starch, which dilutes everything else, including the protein. So the gluten content, if anything, is lower.”
Moreover, Prof Shewry’s co-authored 2013 review, Does Wheat Make Us Fat and Sick?, states that gliadins are present in all wheat lines, and related wild species, while seeds of some ancient types of wheat, such as kamut, may have “even greater amounts of total gliadin than modern accessions”.
3. We eat more gluten now than ever
Again, Prof Shewry disagrees: “I don’t think there is any evidence for that; we probably eat less wheat than we used to.” He is similarly unimpressed by claims that manufacturers are adding ‘more and more’ gluten to bread products.
“Because yield means dilution of protein the industry adds gluten back in to bring it up to the right levels. It needs a minimum amount to make bread properly,” he explains. “But I doubt they are greatly exceeding the levels in bread pre-1960s.”
4. Industrial gluten is bad for you
So-called ‘vital wheat gluten’ – a powdered form of extracted gluten – has been regarded with significant suspicion. A New Yorker article reported that a piece of the protein, placed in a glass of Coke, became a “glob that just sat there for weeks”.
But Prof Shewry says: “Gluten is produced in an industrial process that separates the starch and protein, and is added as dried powder. There is nothing particularly different about the gluten.”
It is called ‘vital’, he explains, because it has not been badly damaged during extraction therefore has similar visco-elastic properties to gluten in flour.
Gluten itself, he adds, is not soluble in water, so sitting it in a cup of Coke will have no effect.
He suggests an experiment: “If people have never seen gluten you can make it yourself from wheat. Make a dough, knead it and wash it gently under a tap. You end up with a piece of stuff that looks like Play-Doh and is about ten per cent of the volume of the dough. It’s stretchy and springs back to an extent.
“That’s what you’d get if you mixed vital gluten with water. Although gluten is not water soluble it is digested to release soluble products.”
5. Wheat is making us fat
There is no evidence for this. In fact, according to Does Wheat Make Us Fat and Sick?: “Foods containing whole wheat, eaten in recommended amounts, have been associated with significant reductions in risks for type 2 diabetes, heart disease and a more favourable long-term weight management.”
Moreover: “The proliferation of wheat products has a much longer history than the more recent drastic increases of occurrence of obesity, which has also occurred in populations that eat little wheat, such as several Asian countries.”
Dr Skypala says: “Gluten-free diets are not for weight reduction. Of course if you cut out lots of high-calorie foods you are going to lose weight and if lots contain wheat that’s coincidental.
“Haven’t we seen this before? With fat, for example? I’ve sat through it all and I think we’ve forgotten. The answer is cook proper meals, eat proper food.”