Study Finds Earlier Egg Introduction Linked to Lower Egg Allergy Rates in Infants

A study published Monday in JAMA Pediatrics compared two Australian population samples of one-year-old infants and found egg allergy prevalence fell from just over 9 percent to 7.6 percent when eggs were introduced earlier. Food allergies affect 1 in 13 children in the U.S. and rose 50 percent between 1997 and 2011.

Factors cited include more refined diets, vitamin D deficiencies, and the hygiene hypothesis that cleaner environments may prompt immune overreaction to certain foods.

Guidelines from the early 2000s recommended avoiding eggs until children reached one to three years of age. The new study recommends earlier introduction. Common infant food allergens include wheat, fish, dairy, nuts, soy, and egg. The general recommendation remains to wait until a baby is at least six months old before feeding eggs.

An attending physician of the Division of Allergy and Immunology at Northwell Health who was not involved with the study said skin exposure to an allergen tends to produce an allergic response while oral exposure tends to produce a protective response.

The physician noted the reduction in egg allergy prevalence was more pronounced in babies with eczema, an inflammatory skin condition that impairs the skin barrier and increases vulnerability to food allergies.

The physician stated maintenance of the allergen several times a week is critical to remain tolerant. Previous research showed introducing peanuts earlier produced a 77 percent decrease in peanut allergies among infants with severe eczema at four months and among those with mild or no eczema at six months.

Another study found infants eating a diverse diet of 13 or 14 different foods by nine months had a 45 percent lower risk of food allergies by 18 months. Food allergies are often genetic, yet diet timing can also influence development.