New research published in The BMJ suggests that women who eat a diet that is high in gluten are at an increased risk of having a baby who will develop type 1 diabetes later in life.
Type 1 diabetes occurs when the immune system attacks cells in the pancreas, resulting in sugar buildup in the blood instead of being used as energy. This particular type of diabetes typically develops in childhood or adolescence, and if untreated, high blood glucose can result in problems such as damage to the heart and the eyes. Approximately 10 per cent of people with diabetes have type 1 diabetes.
The study analyzed data from more than 67,500 pregnancies. It predicted that pregnant women who eat 20 grams or more gluten per day are twice as likely to have a child with type 1 diabetes, compared to pregnant women who eat less than 7 grams of gluten a day. While there certainly appears to be a correlation, the study's co-author warned that women and expectant parents should interpret the study's results with caution.
"At present we don’t recommend any changes in pregnant women’s diet,” said Dr. Knud Josefsen, from the Bartholin Institute in Copenhagen. Josefsen added that even in the womb, environmental factors might have an effect on future risk of type 1 diabetes as well.
During the study, women were asked at the 25th week of pregnancy several questions about their diet in the preceding four weeks. Researchers also asked the women about various aspects of their health and lifestyle, as well as other factors including breastfeeding, the mother’s age, BMI, socioeconomic status, and total energy intake.
The results were telling. A total of 0.3 per cent of children born to mothers in the lowest gluten intake group developed the disease, compared to 0.53 per cent of children born to mothers in the highest intake group. Women in the latter group reported eating at least 20 grams of gluten a day.
Despite the results, only 247 children actually developed type 1 diabetes, which indicates that there may be other factors at play, such as components of the diet, or even of the grains. Josefsen noted that other research has suggested that more dietary gluten is also associated with a decreased risk of type 2 diabetes in the person eating the gluten, which is another concern.
"If we try to eliminate one disease we might induce other diseases," he warned.
Critics of the study suggested that using results from a self-reported diet is prone to error, and the fact that diet was only officially examined at one point in time during the pregnancy is problematic. Two other researchers suggested in their accompanying editorial that it is unclear whether or not infants could be exposed to gluten immediately after birth through breastfeeding, making it hard to determine whether type 1 diabetes is triggered by prenatal exposure, childhood exposure, or both.
The Danish study was published on September 19 and can be read in its entirety here.