Children with celiac disease predisposition are more likely to have the disease if they consume large amounts of gluten, according to a new study published in JAMA. While the study is observational and cannot prove causation, it is the most comprehensive of its kind to date as it followed 6,600 children from Sweden, Finland, Germany and the US from birth until the age of five. The risk of developing pre-celiac disease or celiac disease was highest in two to three-year-olds, which increased noticeably when small amounts of gluten were consumed. The researchers are now calling for further research to see whether a policy revision is necessary.

“We have previously seen in a Swedish population that intake of gluten in genetically at-risk children matters for the development of celiac disease. We know that Swedish infants are traditionally fed with cereal-based foods in a way that those in other countries are not. It was as much a surprise as it was an important finding that we could see the same results in a multinational birth cohort,” Carin Andrén Aronsson, lead author of the article and Dietician at Lund University, tells.

While the mean gluten intake ranged from three to five grams a day depending on the country, a daily gluten intake over two grams in a two-year-old was associated with a 75 percent increase in the risk of developing celiac disease. This is equivalent to one slice of white bread. This connection was found in all countries except Germany, where there was insufficient data.

“Due to gluten’s composition, the protein molecules are not completely broken down. Gluten peptides are transferred into the small intestine where they activate the immune system, triggering an immune response in genetically at-risk children. The action leads to intestine inflammation. The hypothesis is that the higher intake of gluten increases or accelerate this process,” Andrén Aronsson explains.

Clinical trials are required to investigate if there is a safe limit of gluten intake for genetically at-risk children.It used to be thought that the timing of when a child was introduced to gluten influenced disease onset. “However, that is not true. We do know that gluten is one of the major triggers for celiac disease, so the next step was to look at the amount of gluten in the child’s diet. With the data that we collected in the study, we had the possibility to investigate if the amount of gluten is a major risk factor for disease development,” she continues.

Breadcrumbs to a solution
The next step for the researchers is to study which gluten-containing food groups are most significant in the development of celiac disease. “In our study, we looked at the total amount of gluten, but we also included information about the sources; bread, porridge, gruel, pizza or pasta. It is also important to study other environmental triggers that could influence the risk for disease, such as virus infections,” Andrén Aronsson notes.

Additionally, clinical trials are required to investigate if there is a safe limit of gluten intake for genetically at-risk children. If so, this could impact the infant feeding recommendations made by policy-makers.

However, this study only examined children who were genetically at risk of the disease. “You need to have a genetic predisposition to be able to develop celiac disease. If you don’t have the specific HLA-genes, then you will not develop celiac disease,” notes Andrén Aronsson.

Additionally, the majority of the at-risk group do not ultimately develop the disease. “Serious consideration should be taken before issuing advice on a particular diet or food restrictions,” adds Daniel Agardh, Associate Professor at Lund University and Consultant at Skåne University Hospital, and leader of the study.

“Another limitation of this study is that gluten intake was measured using food records over a three-day period, a method that is unlikely to capture gluten exposure from less commonly consumed foods that are eaten only once or twice a week,” says Kevin Whelan, Professor of Dietetics, King’s College London, commenting on the study.

Another recent investigation into celiac disease revealed a new potential way to test for the disease that could cut the need for invasive testing. The proposedblood-based test would be a vast improvement on the current approach, which requires people to consume gluten for a number of weeks, and even months, for the testing to be accurate.