Delayed Introduction of Allergens Increases Allergy Risk

FRANCE — An epidemiologic study of children aged 2 months to 5.5 years using data from the French national birth cohort (ELFE) reveals an increased risk of food allergies linked to a delayed introduction of major allergenic foods. These findings were published in Allergy on July 26.

Launched in April 2011, the French ELFE study aims to monitor children from birth to adulthood to better understand the factors from the intrauterine period to adolescence that affect their development, health, social skills, and school career (see box). Thanks to this cohort, a team of scientists has reviewed the relationship between complementary feeding practices and allergies in French children.

The study focused on 6662 children who had no signs of an allergic reaction before 2 months of age. Data on feeding practices were collected monthly from ages 3 months to 10 months. Their age at complementary feeding introduction was calculated, and a food diversity score was determined at 8 and 10 months. The number of major allergenic foods (out of eggs, fish, wheat, and dairy products) not introduced at 8 and 10 months was also determined. Allergic diseases (food allergy, eczema, asthma, and rhinoconjunctivitis) were reported by parents at 2 months and at 1, 2, 3.5, and 5.5 years.

Initially, scientists determined that just 62% of children began complementary feeding in the recommended age window, which is between ages 4 months and 6 months. They then closely studied the link between delayed introduction of major allergenic foods and the risk of food allergies. They saw that for 1 in 10 children, at least two major allergens, from eggs, fish, wheat, and dairy products, had still not been introduced into the diet of infants by the age of 10 months. Now, these children have a risk of developing a food allergy before the age of 5.5 years that is two times greater than that of children in whom the four major allergens were introduced before the age of 10 months.

These findings therefore confirm the importance of not delaying the introduction of major food allergens to prevent the occurrence of childhood allergic diseases. They provide convincing arguments in support of new recommendations made by the French pediatric and allergy societies as well as those issued by Public Health France.

ELFE: The First Cohort to Follow Children From Birth to Adulthood

ELFE is the first longitudinal nationwide French study dedicated to monitoring children from birth to adulthood. More than 18,000 children born in metropolitan France in 2011 were included in this study, which represents 1 in 50 children born in 2011. From the time that researchers first met the families in the maternity ward, the parents who agreed to participate in this great scientific adventure have been questioned at regular intervals to better understand how environment, family members, and living conditions affect the development, health, and socialization of children.

This article was translated from the Medscape French Edition.

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