A gluten-free diet has been on the rise as a purportedly healthier way to eat — but research out of Harvard University in the United States suggests it could instead be linked to increased risk of type-2 diabetes.

While people with coeliac disease or gluten intolerance avoid gluten as a matter of medical necessity, people without those disorders have also turned to a gluten-free diet as a lifestyle choice.

But research presented to an American Heart Association conference suggests those people could be doing harm to their health by entirely cutting out foods like bread, cereals and pasta.

The study saw researchers estimate the daily gluten intake of more than 200,000 participants in different long-term health studies which spanned more than 30 years.

Over time, the 20 per cent of participants who ate the highest daily amount of gluten were found to have a 13 per cent lower chance of developing type-2 diabetes compared to those who ate the least amount of gluten.

Geng Zong, from Harvard University’s Department of Nutrition, said the results suggested eating foods with gluten could lower people’s risk of type-2 diabetes.

“Gluten-free foods often have less dietary fibre and other micronutrients … making them less nutritious,” he said.

“People without coeliac disease may reconsider limiting their gluten intake for chronic disease prevention, especially for diabetes.”

Questions remain over role in diabetes risk

University of Canberra Associate Professor of nutritional science Duane Mellor said decreased diabetes risk may be linked to foods commonly found alongside gluten, rather than the protein itself.

“It’s unclear whether the gluten is actually the thing that’s protecting them from getting type-2 diabetes,” he said.

“It could be that other things that you tend to find gluten with, we tend to find things like wholegrains, which are associated with a reduction in risk of diabetes.

“We’re waiting for the full paper to come in so we can dig in to the nuts and bolts of the actual research.”

Dr Mellor said what was clear is that eating gluten posed no adverse health impacts for most people.

There’s no evidence for people without a medical reason to avoid gluten or other things found in these grain products to avoid them.

“It’s not ideal to cut out certain complete food groups, there’s nothing potentially an issue with gluten in a healthy gut.

“What is the real reason you’re excluding gluten? Is it because you believe it’s having an effect or is it actually having an effect? For most people it is the belief.”