[Primary Prevention of Food Allergies - Is It Feasible?]

The prevalence of food allergy is increasing in Western countries. In Israel, the estimated prevalence is 2-3% among young children. The rate of natural resolution ranges from 70-80% for milk and egg allergy, to 10-20% for nuts. Food allergy significantly impacts patients' lives, including growth impairment, reduced bone density, worse quality of life, and even increased risk for anxiety disorder. Although effective treatment options exist, they are associated with adverse reactions and require regular long-term consumption of the allergenic food to maintain desensitization. Consequently, a major focus of current research is the potential for primary prevention of food allergies. Until the early 2000s, the prevailing recommendation was to delay the introduction of allergenic foods to reduce the risk of allergy development. However, this approach has since changed significantly, and based on accumulating evidence, international guidelines now recommend early introduction of eggs and peanuts from 6 months of age for the general population, and at 4-6 months for infants at high risk of developing food allergies. The case of cow's milk is more complex and while early introduction likely reduces cow's milk allergy (CMA), this contradicts the WHO recommendation for exclusive breastfeeding (EBF) until age 6 months. Recent studies have shown that intermittent supplementation of cow's milk formula (CMF) during the first days of life, followed by EBF, may increase the risk of developing CMA. Therefore, professional societies worldwide now recommend avoiding transient supplementation of CMF in the first week of life in infants intended to EBF. This recommendation has recently been adopted by the Israeli Ministry of Health, with the support of relevant professional organizations. Furthermore, when supplementation is required in these infants, donor human milk or extensively hydrolyzed formula is recommended. For infants who received CMF in the first days of life, the Israeli Association of Allergy and Clinical Immunology recommends discussing with parents the benefits of EBF versus the potential protective effect of continued regular consumption of CMF alongside BF in reducing the risk of CMA. Further research is needed to determine the optimal timing and quantity of exposure to other allergenic foods (i.e. sesame and tree nuts) to prevent food allergy development.