is characterized by damage to the small intestine caused by gluten—a type of protein present in wheat, barley, and rye that has no ill effect on a majority of people. The condition normally presents itself in early childhood, causing symptoms such as irritability, abdominal pain, diarrhea, and nutrient deficiencies. Because the body's immune response causes the intestinal damage, celiac disease is considered an
. It is also classified as a
disease of malabsorption
because it prevents nutrients from being absorbed.
Celiac disease is hereditary, but only a fraction of genetically susceptible people actually develop the condition, suggesting that other factors come into play. Naturally, dietary intake early in life is thought to play a role, and previous studies have suggested a protective effect from breastfeeding. How much and how often gluten is fed to infants have been investigated as contributing factors, but findings have been equivocal.
In the May 18, 2005 issue of the
Journal of the American Medical Association
, researchers from the University of Colorado at Denver reported results of their prospective study tracking celiac disease development among genetically predisposed children. No studies heretofore had looked at the effect of
of gluten introduction on later development of the disease. They found that infants who received their first dose of gluten-containing food before four months of age were five times more likely to develop signs of celiac disease by age five than those who received it between four and six months of age.
About the Study
Because celiac disease is a somewhat rare condition, affecting less than 1% of Americans, the researchers chose to track development of the disease in a subgroup of
children. The white blood cells of most people with celiac disease carry certain known genetic markers (i.e., antigens). Scientists have found that these same genetic markers are also common among people with type 1 diabetes. In fact, a family history of type 1 diabetes increases risk of celiac disease, and vice versa. Based on these associations, the researchers enrolled 1560 children (newborns up to age three)—mostly from clinics in Denver, CO—who either screened positively for celiac disease antigens or who had a first-degree relative with type 1 diabetes.
In most cases, the researchers collected data regarding the children’s diet from their mothers at 3, 6, 9, 12, and 15 months of age. In addition to gluten intake, the researchers took into account duration and timing of breastfeeding, exposure to oats, rice, and cow’s milk, and several demographic factors such as infant sex, maternal education level, maternal age, and infant race/ethnicity.
The children were followed for an average of 4.8 years to see whether they developed signs of celiac disease autoimmunity called transglutaminase (tTG) antibody in the blood. When possible, they confirmed positive blood test results with biopsies of the small bowel.
With this data in hand, the researchers set out to determine if timing of gluten introduction played a role in the development of celiac disease autoimmunity later on in childhood. They used four to six months of age as a reference point because the American Academy of Pediatrics recommends the first introduction of solid foods during this time.
Fifty-one children (3.3%) developed evidence of celiac disease. Twenty five of these children had biopsy confirmed cases. Major findings included:
Children exposed to wheat, barley, or rye in the first three months of life had a five-fold increased risk of celiac disease autoimmunity compared to those exposed at 4-6 months. Children not exposed until their seventh month or later were also at increased risk, but only slightly.
Among the 41 children who were at the greatest risk according to their genetic markers, those exposed to wheat, barley, or rye in the first three months of life had nearly an eight-fold increased risk of celiac disease autoimmunity compared to those exposed at four to six months.
No protective effect of breastfeeding was observed.
These findings were consistent even when the researchers limited their analysis to only the 25 cases of biopsy-confirmed celiac disease.
How Does This Affect You?
These findings indicate not only that it may be unsafe for genetically predisposed children to receive gluten-containing foods when they are too young—when plausibly their immune systems are fragile and immature. They also suggest that waiting too
may also pose a risk. This latter finding is more mysterious, indicating that factors other than timing may play a role. One possibility, suggested by the study’s authors, is that parents who introduce gluten-rich food when their child is older may provide it in larger amounts and/or more frequently. This may have a detrimental effect on their infant’s intestinal ability to process the protein.
Because of this study’s limitations—namely, small size, short-term follow up restricted to early childhood, and the fact that the primary outcome measured was autoimmunity for the disease versus full-blown symptoms—other studies are needed to confirm these findings. Moreover, population-wide studies would be necessary to determine how the timing of gluten introduction influences development of the disease in children at average risk.
As they stand, these findings do not alter
recommendations for introducing wheat and other gluten-containing foods into the infant diet. However, in an addendum, the study’s authors note that the American Academy of Pediatrics (AAP) recently published a policy statement recommending exclusive breastfeeding for the first six months of life. They point out, however, that the AAP does acknowledge that “unique needs or feeding behaviors of individual infants [could] indicate a need for introduction of complementary foods as early as four months of age…” Children at high risk for celiac disease or type 1 diabetes may very well have unique nutritional needs even in infancy.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a