A paper published in the British Medical Journal which explored the possible impact of gluten consumption by mothers on the risk of their children developing Type 1 Diabetes has highlighted a potential nutritional relationship.
The researchers from Denmark found that children of women with the highest gluten intake, of 20g or more a day, were twice as likely to develop type 1 diabetes by their mid-teens as those with the lowest gluten intake, of under 7g per day. The risk appeared to increase gradually in line with increased consumption. On average women consumed 13g of gluten per day.
Unlike type 2 diabetes, which is linked to diet and obesity, the causes of type 1 diabetes are unclear. However, the disease has become increasingly common in the western world, leading academics to start searching for potential lifestyle factors.
They used data from 63,529 pregnant women enrolled into the Danish National Birth Cohort between January 1996 and October 2002. The researchers took into account other factors that might have had an impact, including the mothers’ ages, weights, total calorie consumption and whether they smoked. It follows animal studies that have shown a gluten-free diet during pregnancy can almost completely prevent type 1 diabetes in offspring.
The incidence of type 1 diabetes is highest in countries following a western lifestyle, and, until recently, it has been increasing at a rate of 3-4% per year, especially in children below 5 years of age in Europe. This increase is faster than can be accounted for by genetic drift, pointing to the importance of environmental factors. Gluten proteins found in wheat, rye, and barley are believed to be important in diabetes development; they are rich in proline and glutamine, which makes them highly hydrophobic and partly resistant to intestinal degradation. These properties make them more immunogenic than other dietary proteins, which are efficiently hydrolysed into single amino acids or dipeptides or tripeptides.
The possible effect of maternal gluten intake on risk of type 1 diabetes in offspring might be related to the complex interplay between diet, immune development, microbiota, and intestinal permeability, which could all affect the pathogenesis of type 1 diabetes. There are regional differences in the effect of probiotics and type 1 diabetes development as well as in the microbiome and structure of gluten and in the gluten content of crops. The effect of gluten intake during pregnancy could therefore vary geographically. In humans, the establishment of the microflora early in life might affect children’s risk of chronic immune disorders; babies delivered by caesarean section have a 23% increased risk of onset of type 1 diabetes in childhood.
Whilst this study cannot provide causality it raises some questions about possible causes for the gain in numbers being diagnosed over the last 30 years.
 Antvorskov Julie C, Halldorsson Thorhallur I, Josefsen Knud, Svensson Jannet, Granström Charlotta, Roep Bart O et al. Association between maternal gluten intake and type 1 diabetes in offspring: national prospective cohort study in Denmark BMJ 2018; 362 :k3547 View Full Paper