Food allergies are reported to be on the increase with between three to six percent of US children reported to be intolerant to some type of food. The most common allergies are egg, milk, soy, peanut, wheat, and fish/shellfish. The prevalence of wheat allergy is not accurately known.
Several studies have suggested that introduction of solid foods between three and four months may increase the risk of asthma and eczema. On the flip-side, a retrospective study from Europe reported that delaying solid foods did not affect intolerance, and may even increase it in certain cases.
These differences are also reflected in the recommendations from various pediatric societies. The joint committees of the European Society for Paediatric Allergology and Clinical Immunology and the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition currently recommend breast feeding for four to six months, with solid food introduction at month five.
However, the American Association of Pediatrics (AAP) recommends exclusive breast feeding until six months of age.
The new research by scientists from the National Jewish Medical and Research Center and the University of Colorado at Denver suggests that delaying the exposure to cereal grains until after six months may increase the risk of developing an allergy to wheat.
The researchers, led by Jill Poole, MD, enrolled 1612 children at birth and followed them for an average 4.7 years. Dietary and allergy information was gathered by interviews of the mothers and completion of questionnaires every three months for the first 15 months, and then every year after.
Of the cohort population, 59 percent of the children were exposed to cereal grains before six months, with only 0.41 per cent developing an allergy to wheat, as detected by the presence of wheat-specific immunoglobulin E (IgE). For the 41 percent of the children with exposure to cereal grains delayed until after six months, 1.8 percent developed an allergy to wheat - that is four times the wheat allergy of the early exposure group.
The children who had a history of other food allergies before six months were also associated with an increased risk of wheat allergy.
Dr. Poole told FoodNavigator-USA.com that this study suggested that the timing of food introduction, and particularly cereal, in the diet may be very important in altering the immune system response.
"For the food industry and understanding nutrition, it would be important for parents of infants to know that it is not only "ok," but maybe even beneficial to feed their children cereal grains that contain gluten products (wheat, barley, rye, oats) in a four to six month window," Dr. Poole told FoodNavigator-USA.com.
Dr. Poole did say that the diagnosis of wheat allergy was not confirmed by a double-blind placebo-controlled food challenge (DBPCFC), but stressed that such a test is rarely used.
Further research is needed, and an ideal study, said Dr. Poole, would be to randomize children to receive an "early" introduction of food diet versus a "late" introduction of food diet. Such a study would not be easily coordinated though, while another important next step should be to tackle peanut allergy, the worst for children because it can be fatal.
"Our take home message [from this study, however] is that introduction of cereal grains should not be delayed beyond 6 months of age," she said.