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 new study by Harvard University suggests that ingesting only small amounts of the protein, or avoiding it altogether, increases the danger of diabetes by as much as 13 per cent.
The findings are likely to horrify the rising number of people who are banishing gluten from their daily diet, encouraged by fashionable “clean eating” gurus such as Jasmine and Melissa Hemsley.
People without Celiac disease may reconsider limiting their gluten intake for chronic disease prevention, especially for diabetes
Dr Geng Zong, Harvard University
Gluten is found in wheat, rye and barley and gives food a chewy texture and elasticity during the baking process.
Only around 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 the UK at more than 12 per cent.
The researchers behind the new study have now suggested people limiting their gluten intake who are not coeliacs should think again, and pointed out there is no evidence that going gluten-free has any health benefits.
The Harvard team examined 30 years’ of medical data from nearly 200,000 patients.
The found that most participants had a gluten intake of below 12g a day, roughly the equivalent to two or three slices of wholemeal bread.
Within this range, those eating the highest 20 per cent of gluten had a 13 per cent lower risk of developing type 2 diabetes compared to those eating up to 4g a day.
The study showed that those who eat less gluten also tended to eat less cereal fibre, a substance known to protect against diabetes, however this was adjusted for in the results.
“We wanted to determine if gluten consumption will affect health in people with no apparent medical reasons to avoid gluten,” said Dr Geng Zong, a Harvard research fellow.
"Gluten-free foods often have less dietary fiber and other micronutrients [such as vitamins and minerals], making them less nutritious and they also tend to cost more.
“People without coeliac disease may reconsider limiting their gluten intake for chronic disease prevention, especially for diabetes.
It is estimated that more than four million people are currently living with Type 2 diabetes in the UK at present,around 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, as in the new study, potentially a lack of micronutrients, or presence of unhealthy ingredients to replace gluten.
The UK “free from” market is growing rapidly and expected to be worth £550 million by 2019.
Market analysis Mintel claim that in 2015 12 per cent of new food products launched in the UK 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 such as Gwyneth Paltrow, as well as a new culture of posting photographs of food on social media.
The new 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.