If you have celiac disease, you may have heard of the Swedish CD epidemic. Between 1984 and 1996, four times the average number of children under the age of two years in Sweden were diagnosed with CD. This increase in celiac disease rates, which later returned to normal levels, has given researchers much useful data. They are trying to learn how genetics, feeding practices and other factors may affect the development of CD. Evidence that repeated infections early in life can increase the risk of celiac disease has come from the study of the epidemic.
Sweden has a national healthcare system, and people tend to follow suggestions about how to feed their babies, what vaccines should be given and other advice. Records are available for many of the children diagnosed with CD during the above years.
CD was diagnosed according to strict guidelines at the time of the epidemic. A child had to have an abnormal intestinal biopsy while eating gluten, followed by a normal biopsy off gluten and a third abnormal biopsy back on gluten.
There was a definite change in the way food was given to infants during the epidemic years. It has already been suspected that the early introduction of medium to large amounts of gluten after breast feeding had ended, led to the higher risk of CD. The recent study confirmed this, but also found that repeated infections during the first two years of life along with these feeding practices increased the rate of celiac disease.
The term used when two factors increase something more than just expected by adding the two together is called synergy. There appears to have been synergy at work during the epidemic, with repeated early infections and giving babies a lot of gluten after breast feeding has been stopped causing the highest risk.
Researchers studying the epidemic compared two groups of children, 373 who had celiac disease and 581 who did not but were otherwise similar in age, sex, and where they lived. Parents were given questionnaires asking about early infections (in infants less than six months old), what the infections were, if the infants got antibiotic treatment, how and what they fed their infants, a variety of questions related to the parents’ work, and whether or not there were other children in the family, among other questions.
The answers to these questions were analyzed, comparing the young children with celiac disease to those who did not have it. The infants with celiac disease were different than those without it in the following ways:
• They had more early infections
• They first ate food with gluten after they were no longer breast feeding
• They ate medium to large amount of foods with gluten
• Their families had less money
Three or more infections in infants younger than six months old was associated with a higher risk of celiac disease. These did not have to affect the intestinal tract, but could have been a cold, ear infection, chickenpox, or other common illness. Use of antibiotics did not change the risk.
Those infants who had three or more infections and ate a lot of food containing gluten, especially if started after breast feeding had been stopped, had even more chance of celiac disease than if these factors were just added together. It seems that there was a synergistic effect at work.
Infant feeding practices in Sweden were changed at around the time rate of celiac disease started to drop.
There will be continued work looking at the epidemic in Sweden in the hopes that what is learned can be used to help lower the risk of celiac disease.