In animal studies, a gluten free diet during pregnancy almost completely prevented type 1 diabetes in offspring, but no intervention study has been undertaken in pregnant women.
Researchers from the Bartholin Institute in Denmark set out to examine whether gluten intake during pregnancy is associated with subsequent risk of type 1 diabetes in children. They analysed data for 63,529 pregnant women enrolled into the Danish National Birth Cohort between January 1996 and October 2002.
Women reported their diet using a food frequency questionnaire at week 25 of pregnancy and information on type 1 diabetes in their children was obtained through the Danish Registry of Childhood and Adolescent Diabetes.
Average gluten intake was 13 grammes per day, ranging from less than 7 grammes per day to more than 20 grammes per day, and the researchers identified 247 cases of type 1 diabetes (a rate of 0.37 per cent) among the participants’ children.
After taking account of potentially influential factors, such as mother’s age, weight (BMI), total energy intake, and smoking during pregnancy,they found that the child’s risk of type 1 diabetes increased proportionally with the mother’s gluten intake during pregnancy (per 10 grammes per day increase). For example, children of women with the highest gluten intake (20 grammes per day or more) versus those with the lowest gluten intake (less than 7 grammes per day) had double the risk of developing type 1 diabetes over a mean follow-up period of 15.6 years.
The mechanisms that might explain this association are not known, but could include increased inflammation or increased gut permeability (so-called leakiness of the gut), researchers said.
However, more evidence is needed before changes to dietary recommendations could be justified, they said.