High-gluten diet during pregnancy increases child's type 1 diabetes risk, study suggests

'Public should be aware of the possibility that consuming large amounts of gluten might be harmful,' say researchers

Women who have a high-gluten during pregnancy could increase the risk of their children developing type 1 diabetes, a study suggests (PA)

Children whose mothers have a high-gluten diet during pregnancy are at increased risk of diabetes, according to new research.

A study involving tens of thousands of pregnant women found the likelihood of their children developing type 1 diabetes “increased proportionately” to maternal gluten intake.

However, experts said the findings did not prove gluten caused the condition and it was “too early to change dietary recommendations”.

Previous studies among animals have suggested a gluten-free diet during pregnancy almost completely prevented the condition among offspring.

An international team of researchers set out to examine whether a similar effect was found in humans.

The study, published in The BMJ, formerly the British Medical Journal, examined data on more than 63,000 pregnant women from Denmark.

The women, who were enrolled into the Danish National Birth Cohort between January 1996 and October 2002, completed a food-frequency questionnaire when they were 25 weeks pregnant.

The survey measured their consumption of gluten, found in common foods such as bread, pasta and cereal.

Participants were followed up until 2016 to track the development of type 1 diabetes among their children.

Researchers found the daily gluten intake among women ranged from 7g to 20g, with an average of 13g.

There were 247 cases of type 1 diabetes among participants’ children after an average follow-up period of 15.6 years.

Researchers at the National Institute for Health and Welfare in Finland concluded that the risk of type 1 diabetes in children “increased proportionately” with maternal gluten intake.

Children of women with the highest gluten intake had double the risk compared to those with the lowest intake.

The study’s authors said more evidence was needed before health officials made recommendations to change pregnant women’s diets.

In a linked editorial, they wrote: “Given that a causal association between maternal gluten intake and type 1 diabetes in children has not yet been established, it is too early to change dietary recommendations on gluten intake in pregnancy.

“However, doctors, researchers and the public should be aware of the possibility that consuming large amounts of gluten might be harmful, and that further studies are needed to confirm or rule out these findings, and to explore possible underlying mechanisms.”

Jenny Myers, a senior lecturer in maternal and fetal health at the University of Manchester, who was not involved in the study, said the findings were “interesting” but did not mean pregnant women should cut gluten from their diet.

She added: “What we lack are mechanistic studies which can explain the biology of these observations – only then can we begin to design dietary interventions and be able to advise pregnant women properly. Women should not make radical changes to their diet based on this evidence – it is important during pregnancy to eat a balanced diet and there is no evidence currently that gluten should be excluded from the diet during pregnancy.”

Experts have previously warned that gluten-free diets – popularised as a wellness trend in recent years - could be unhealthy for people who do not have coeliac disease.

A study by nutritional scientists at Harvard University last year identified a possible link between gluten-free diets and type 2 diabetes.

Responding to the latest study, Lucy Trelfa, research communications officer at Diabetes UK, said it was “far too early to say just how big a player gluten is”.

She added: “Importantly, this research does not show that gluten causes type 1 diabetes. Scientists are looking at a range of factors in our genes and our environment, like gluten, that might increase the risk of developing type 1 diabetes. But how those factors work together, and their individual importance, is still unclear.

“We need to understand what causes type 1 diabetes if we’re to prevent it, and research like this takes us closer. At this stage, pregnant women don’t need to make any lifestyle changes based on this research. And anyone concerned about their pregnancy should speak to a healthcare professional.”