Early Introduction Is the New Standard for Food Allergy Prevention

20 May 2016 --- Canadian research has found that egg, peanut, and milk allergies can be prevented by adding all three foods to an infant’s diet before age 1 year. Although there are treatment options available for childhood food allergies, many experts have moved toward preventing them altogether – and the standard for allergy prevention has now shifted from delayed to early introduction of these foods.

Results from the Canadian Healthy Infant Longitudinal Development Study show that children who eat egg, peanut, and cow’s milk products before the age of one are less likely to become allergic to these foods. Researchers from McMaster University in Canada presented these findings at the American Thoracic Society’s 2016 International Conference this week. 

“There’s some literature that suggests there is a critical window of development in infancy, maybe between 4 to 6 months, whereby early introduction of foods could induce tolerance instead of sensitization,” said lead investigator Maxwell Tran. Tran called this study "the first to determine the effects of timing of food introduction to cow's milk products, egg, and peanut, on food sensitization at age 1 in a general population-based cohort," in a statement.

Tran and colleagues gathered data on 1,421 children at the ages of 3, 6, 12, 18, and 24 months old to record how long parents exclusively breastfed their kids; the diversity of foods parents introduced them to; and when eggs, peanut products, and cow’s milk products were added to their diets. Each infant underwent skin prick testing to determine whether they had developed allergies to those foods by their first birthday.

The vast majority of parents introduced cow’s milk products, often via cow’s milk-based formula, to their children before the age of 1, and 48 percent did so between 0 and 6 months. On the other hand, most parents delayed introducing eggs: Six percent of parents introduced eggs between 0 and 6 months, 76 percent between 7 and 12 months, and 19 percent after 12 months.

Overall, introducing each food product before the age of 1 year was associated with a lower risk for sensitization to the corresponding food allergen. Introducing eggs during that time led to a significant drop in the odds of becoming allergic to any of the three food allergens. While less food diversity was associated with a higher risk for all allergies, exclusive breastfeeding to 6 months was only linked to cow’s milk allergies.

“It’s possible that delayed food introduction and avoidance have led to an increase in food allergies over the years,” Tran added. “But more recently, there have been plenty of observational studies and a couple of randomized controlled trials that have showed protective effects of early food introduction for allergy prevention. The results of our study definitely support that and that’s why we’re now seeing these new recommendations around the world that suggest there’s no reason to delay the introduction of foods beyond 6 months, or even 4 to 6 months.”

In spite of the many proven benefits tied to breastfeeding, evidence has shown that it can lead to the development of certain food allergies. Food proteins found in human breast milk, especially mothers with a family history of allergies, can trigger the development of food allergies. Around six million children in the United States are living with a food allergy, which is equivalent to one out of every 13 kids.

Researchers from the National Institute of Allergy and Infectious Diseases conducted a similar study that compared the eating habits of children from Israel, who were given peanuts at an early age, and Jewish children living in the United Kingdom, who did not eat peanuts. Introducing peanuts early in life lowered Israeli children’s risk for developing an allergy to them by 81 percent.

However, before parents add peanuts to their child’s foods, the American Academy of Allergy, Asthma and Immunology still recommends that they check with their doctor or allergist to make sure their child is not at a higher risk. Upon receiving approval, allergenic foods should only be introduced after complementary foods and only at home as opposed to a restaurant or daycare. Parents should also gradually increase the amount of allergenic food if no allergic reaction occurs. Lastly, parents should begin introducing one new food every three to five days.