Doctor: Hélène Amazouz
Title: Diet and respiratory health/allergy in urban children : the PARIS (Pollution and Asthma Risk˸ an Infant Study) birth cohort
Supervisors: Isabelle Mommas, Fanny Rancière
Doctoral school: ED 393 Epidemiology and Biomedical Information Sciences, Université Paris Cité
Date of thesis defense: 11/2021
Jury: Marie-Aline Charles, Isabelle Romieu, Marina Kvaskoff, Nhân Pham-Thi.
In recent decades, the prevalence of allergic diseases has increased, especially in industrialized countries. This prevalence is currently estimated at 25% in France. Genetic, social, environmental, and behavioral risk factors can influence the occurrence of respiratory diseases and allergies in children, and the role of diet is still unclear. Objectives. In this context and using data from the PARIS (Pollution and Asthma Risk: an Infant Study) birth cohort, my doctoral research in epidemiology aimed: (1) to identify and characterize infants’ feeding profiles and children’s dietary patterns at 8 years old, as well as the trajectories between infant and child feeding groups; (2) to assess and characterize the adherence to the Mediterranean diet (MD) at age 8 years; (3) to investigate the associations of infants’ feeding profiles/children’s dietary patterns/MD adherence groups with respiratory and allergic morbidity at 8 years of age. Material and methods. Infants with similar feeding practices over the first year of life were grouped using unsupervised multidimensional longitudinal cluster analysis (kml3D) considering: breastfeeding, type of infant formula consumed and solid food introduction. At 8 years of age, dietary patterns were assessed using an unsupervised method (k-means) and two MD adherence scores. Their associations with respiratory health (spirometry [FEV1, FVC], measurement of the fractional exhaled nitrogen oxide [FeNO]) and allergies (diagnoses of asthma, rhinitis and eczema and allergen sensitization) were studied using multivariable logistic and linear regression models adjusted for potential confounders. Results. PARIS children’s diet was associated with respiratory health and allergies at age 8 years. Five infants’ feeding profiles were identified. Compared to children characterized by standard infant formula consumption, children of the “breastfeeding” profile tended to have a lower risk of asthma at school age. In addition, children from the “partially hydrolyzed infant formula with a hypoallergenic label” profile had an increased risk of being sensitized, of having FeNO> 20 ppb (marker of bronchial inflammation) and lower respiratory function parameters (FEV1, FVC) at 8 years. One feeding trajectory was identified: children from the “breastfeeding” profile were more likely to belong to the “healthier” dietary pattern at school age. Regarding diet during childhood, a “healthier” or “more diverse” dietary pattern or high adherence to the MD at age 8 was found to be beneficial regarding respiratory health, asthma, and allergen sensitization. Conclusion. This work contributes to improving knowledge on the links between diet during infancy and respiratory health/allergies at school age. These results support current public health recommendations favoring breastfeeding and healthy eating during infancy.