Gluten-free fad diet may raise risk of diabetes

"Gluten-free foods often have less dietary fibre and other micronutrients, making them less nutritious." Dr Geng Zong, Harvard research fellow

UNITED STATES: Gluten-free diets adopted by increasing numbers of health-conscious consumers actually enhance the risk of developing type 2 diabetes, scientists have warned.

A major study by Harvard University suggests that ingesting only small amounts of gluten, or avoiding it altogether, increases the danger of diabetes by as much as 13 per cent.

Rising numbers of consumers are banishing gluten from their daily diet, encouraged by fashionable ‘‘clean eating’’ gurus such as Jasmine and Melissa Hemsley. Gluten is found in wheat, rye and barley and gives food elasticity during the baking process.

About 1 per cent of people are genuinely gluten-intolerant, a condition called coeliac disease.

However, some estimates put the proportion of adults adhering to gluten-free diets in Britain at more than 12 per cent. The researchers behind the new study have now suggested that people who are not coeliacs should reconsider limiting their gluten intake.

The Harvard team examined 30 years of medical data from nearly 200,000 patients. They found most participants had a gluten intake of below 12g (0.4oz) a day, roughly the equivalent to two or three slices of wholemeal bread.

Within this range, those eating the most gluten had a 13 per cent lower risk of developing type 2 diabetes compared with those eating 4g a day.

The study showed those who ate less gluten also tended to eat less cereal fibre, a substance known to protect against diabetes, however this was adjusted for in the results.

‘‘Gluten-free foods often have less dietary fibre and other micronutrients [such as vitamins and minerals], making them less nutritious and they also tend to cost more,’’ said Dr Geng Zong, a Harvard research fellow.

It is estimated more than 4 million people have type 2 diabetes in Britain, about 6 per cent of the population. The disease occurs when the pancreas does not produce enough insulin, or the body’s cells do not react to insulin, and it is most commonly associated with obesity rather than a lack of micronutrients.

The British ‘‘free-from’’ market is growing rapidly. Market analyst Mintel claims that in 2015, 12 per cent of new food products launched in Britain carried a gluten-free claim, up from 7 per cent in 2011.

Last year, Catherine Collins, the chairman of the British Association of Dieticians, said the dramatic increase in people opting for ‘‘free-from’’ diets was partly down to the rise of celebrity food bloggers as well as a new culture of posting photographs of food on social media.

The research was presented yesterday at a meeting of the American Heart Association in Portland, Oregon. The study was observational, meaning participants reported their gluten consumption. - Telegraph Group