Type 1 diabetes is a condition characterized by high blood sugar (glucose) levels caused by a total lack of insulin in the body. This lack of insulin occurs when the body’s immune system attacks and destroys the insulin-producing cells of the pancreas, a process called islet autoimmunity (IA). IA prevents the pancreas from producing insulin, the protein responsible for moving glucose from the blood into the cells where it is used for energy.

IA may be present for years before a child is diagnosed with type 1 diabetes. Some researchers believe certain foods, if introduced into a child’s diet at an early age, may trigger the development of IA. However, research in this area has been inconsistent and sometimes contradictory.

In the October 1, 2003 issue of the Journal of the American Medical Association, two studies examined the impact of several common foods (cereal, breast milk, dairy products, and products containing gluten, a protein found in wheat flour) on the incidence of IA in children who are at risk for developing type 1 diabetes.

The first study found that introducing cereal into the diets of high-risk infants between birth and three months or over seven months of age may increase their risk of developing IA.

The second study looked at the timing and duration of breastfeeding, the introduction of dairy products, and the introduction of solid foods. It found that giving an infant solid foods (particularly foods containing gluten) earlier than three months of age may also increase the child’s risk of developing IA.

About the studies

The first study enrolled 1183 infants with family histories of type 1 diabetes. The researchers recorded the age of the infants’ initial exposure to cereal and whether or not they developed IA. They also collected blood samples from each child at the ages of 9, 15, and 24 months and every year thereafter, and tested each for the presence of three antibodies capable of harming insulin-producing cells. Any child who tested positive for one or more antibodies on two consecutive visits or for type 1 diabetes was defined as having developed IA.

The second study followed 1610 infants born to parents with type 1 diabetes. The researchers collected blood samples at birth, nine months, and two, five, and eight years of age. Again, the researchers tested for antibodies indicating the development of IA in two consecutive blood samples. They used family interviews and questionnaires to collect information on breastfeeding habits and food supplementation.

The findings

In the cereal study, infants between the ages of zero to three months or after the age of seven months who received cereal for the first time had a higher risk of developing IA than those who first received it between the ages of four to six months.

In the breastfeeding and solid food study, the researchers found that adding gluten-containing foods to the diets of infants less than three months old who had family histories of type 1 diabetes significantly raised their risk of developing IA. They also found that breastfeeding had no association with the development of IA.

How does this affect you?

Based on the results of the first study, researchers believe that there is a window of opportunity for introducing cereal into an infants diet between the ages of four and six months. Introducing cereal either before or after this window, at least in children at risk for developing type 1 diabetes, may increase their risk of IA.

The results of the second study point to a similar window of opportunity with the introduction of gluten-containing solid foods. The study found that introducing gluten-containing solid foods (such as breads, biscuits, cakes, porridge, pasta, or flour products) to children under three months of age resulted in a five times greater risk of developing IA than if it had been introduced after three months of age.

How do the researchers explain these findings? One possibility is that introducing certain foods too soon may trigger an abnormal immune response in an infant whose immune and digestive systems are not mature enough to handle novel foods. It is also possible that delaying the introduction of these foods until infants are older increases their quantity, which places their young systems under added stress.

In general, the American Academy of Pediatrics recommends that solid foods, particularly cereals, not be introduced until the child is four to six months of age. Based on these two studies, it sounds like they got it right.