Affiliations : University of Strasbourg
Journal reference: doi: 10.1159/000457920
Summary: Breastfeeding has many advantages since it contains immunity factors. This protects against many health problems during childhood, such as obesity, diabetes, infections, and contributes to reducing the risk of disease later in life. In this article Dr. El Hachem explores the role breastfeeding plays in reducing the risk of asthma.
Breastfeeding has many benefits for the health of both mother and child. Indeed, the composition of breastmilk promotes the healthy development and survival of the child. Its content of immune factors protects against many health problems during childhood, such as obesity, diabetes, infections, and contributes to reducing the risk of disease later in life. Epidemiological studies combined with the growing knowledge of genetics and research underline the importance of breastfeeding.
Asthma is the most chronic childhood disease and the leading cause of morbidity among children worldwide. The prevalence of asthma in children worldwide has been increasing over the decades, and a number of theories have been proposed to explain this surprising trend. Sensitivity to asthma can be accentuated by early life factors, including low birth weight, preterm birth, young maternal age and male gender. Breastfeeding is particularly implicated in this disease, as it has been shown to protect against early respiratory infections. However, the question remains of how this comes to occur?
Although many studies indicate that breastfeeding protects against lower respiratory tract infections in early childhood, it’s role in lending protection against asthma has been a controversial subject for over 80 years. In general, studies demonstrate a protective effect of breastfeeding against allergies, even if these studies were often limited by their methodologies. Indeed, breast milk in its complexity contains components that interact with the infant’s immune system and intestinal environment, in addition to allergens, antibodies, polyunsaturated fatty acids and immunological mediators that protect against infections and allergic diseases during early childhood. For example, the transforming growth factor β is a cytokine (small protein important in cell signaling or cell communicating) present in breast milk that is involved in maintaining intestinal homeostasis, regulating inflammation (a protective body response to harmful stimuli) and developing oral tolerance in the baby.
Increased hygiene standards in modern society has changed the intestinal flora of infants, potentially impacting the risk of developing immune-mediated diseases, including allergic diseases such as asthma. However, microbial diversity is essential for healthy immune maturation and function. Studies have shown that compared to breastfed infants, those who were fed formula had lower bacterial diversity and altered intestinal microbiota in the first weeks of life, associated with an increased risk of eczema and asthma. In addition, favorable intestinal colonization through continuous breastfeeding may promote tolerance and protection of the child when complementary feeding is initiated.
In practice today, exclusive breastfeeding until at least 6 months of age, with continuous breastfeeding up to 2 years of age is recommended, to protect against early infections and strengthen the immune system. Experts recommend that infants should be introduced to the “tastes” of allergenic foods, such as eggs and peanuts, slowly from 4 to 6 months of age to develop oral tolerance, and that breastfeeding mothers should have a healthy diet to ensure the quality of their breast milk and improve the quality and diversity of their microbiota and that of their child.