Early in life, the seeds of allergies may be planted i. Maternal diet Early in life, the fetus absorbs nutrients through the placenta. Therefore, through maternal metabolism, the mother’s diet can influence the immune response of the offspring and even the fetus before birth, thus affecting whether the infant develops allergies. Some studies have shown that supplemental intake of fish oil during pregnancy can reduce the risk of allergic sensitization as well as atopic dermatitis in children. In addition, maternal intake of vitamin A and vitamin B can prevent children from developing allergic arthritis. In addition, specific nutrients, such as fish oil, milk, peanuts, and wheat, have immunomodulatory effects, thereby reducing the sensitivity of the newborn to allergens. The intake of these food allergens by pregnant women can reduce the risk of allergic reactions and asthma in their children. For example, maternal intake of peanuts reduces the likelihood of peanut allergy in children, maternal intake of milk reduces the risk of asthma and allergic arthritis in children, and maternal intake of wheat during the fourth to sixth trimester of pregnancy reduces the likelihood of allergic skin disease in children. Notably, maternal intake of methyl-rich foods such as folic acid, vitamin B12 and choline can increase the severity of allergic airway disease in offspring, which is associated with increased methylation modifications of genes, as methylation can suppress the expression of genes that control allergic disease-related genes; therefore, food-induced methylation modifications can increase the likelihood of allergic airway disease in children. Second, breastfeeding Maternal meals not only modulate the immune response in utero, but through breastfeeding, breast milk contains food allergens and aeroallergens that are also ingested by the child, thus causing an immune response. Recent studies have shown that exposure of the mother to allergens during breastfeeding, or exposure of the newborn to allergens helps to induce oral tolerance to these harmless antigens, thus preventing the development of allergies in the infant. Breastfeeding is also strongly associated with the development of allergic diseases in children, particularly childhood atopic dermatitis, asthma in early childhood, and allergy to milk. A recent systematic review has shown that breastfeeding can prevent the development of asthma in children until the age of 6 years, with a particularly protective effect in children younger than 2 years. In addition, although there are no epidemiological investigations directly demonstrating the relationship between the levels of allergens in breast milk and the levels of immunoglobulins due to allergens and the development of allergic diseases in breastfed children, most studies conclude that maternal dietary avoidance of allergens has no preventive effect on allergic diseases in children. III. CHILDREN’S DIET Increasing exposure to food antigens in the first year of life reduces the risk of asthma, food allergy, allergic arthritis and allergic sensitization in children before the age of 6 years. According to the recommendations of the American Board of Pediatrics and the European Commission of Allergy and Clinical Immunology, the addition of complementary foods can be initiated at 4-6 months of age: Routine intake of fish by infants before 1 year of age reduces the risk of allergic disease and sensitivity to food or airborne allergens by age four. Early intake of fish oil in infants to increase levels of omega-3 polyunsaturated fatty acids reduces the intensity of the allergic response response. We do not recommend the ingestion of untreated milk before 1 year of age because of its potential for pathogenic contamination. Studies have shown that ingestion of untreated milk before 1 year of age is negatively associated with the likelihood of developing asthma and allergic arthritis. Also, data suggest that whey proteins such as bovine serum albumin, alpha-lactalbumin and beta-lactalbumin, which are components of untreated milk, are also negatively associated with the likelihood of asthma.