The study, which began in 2008, examined 8,700 newborn babies from the US, Germany, Finland, and Sweden. The study has followed the children for the past six years, and the analysis is expected to continue until 2025.
Results of the study thus far revealed that girls are twice as likely as boys to become gluten intolerant – and Swedish girls are at the highest risk of all. About 3 percent of the Swedish population is gluten intolerant, compared with the study's international average of 1.5 percent. Swedish children also are affected by the disease at an earlier age than children in other countries.
Several researchers said they suspected that risk levels were highly dependent on nursing and when gluten was introduced into an infant's diet.
"Diet is of course an important factor, but the situation is possibly much more complicated than that," Daniel Agardh, doctor at Lund University and leader of the Swedish portion of the study, told newspaper Dagens Nyheter on Thursday.
Many Swedish children are fed välling, a sort of thin porridge, at a very early age, and Agardh said that that the gruel may play a role but that it was uncertain.
Rates of celiac disease vary within Sweden as well, with the condition being more common in the south than the north, the report revealed. Researchers have not come to a conclusion why that may be the case.
Gluten intolerance is largely hereditary, with 60 to 70 percent of the population lacking the genes to ever develop the disease. Determining whether or not those with the gene will develop the disease, however, is more difficult.