Doctor: Roland Andrianasolo
Title: Diet and asthma in the NutriNet-Santé cohort
Supervisors: Pilar Galán, Raphaelle Varraso
Doctoral school: ED 146 Doctoral school Galilée, University Sorbonne Paris Nord
Date of thesis defense: 10/2019
Jury: Carole Planès
The general aim of this thesis was to study the associations between diet and asthma, definedby the asthma symptom score and asthma control among participants in the NutriNet-Santécohort who answered a specific questionnaire on respiratory health. The thesis consisted intotwo main parts according to the dietary estimation method: a first part focusing on specificfoods and nutrients, and a second part based on a global approach taking into considerationthe overall nutritional quality of the diet by using a priori dietary scores.In the first part of the thesis, we investigated the potentially harmful role of a specific food,processed meat, on respiratory health. The analyses showed that high consumption ofprocessed meat (more than 5 servings/week) was associated with greater asthma symptoms,and, this association was even much stronger when consumption of processed meat wascombined with other risk factors such as overweight or obesity, smoking and poor nutritionalquality of the diet. Secondly, we showed that higher intakes of dietary fiber, mostly insolublefiber and fiber from cereal, were associated with fewer asthma symptoms and greater asthmacontrol. We did not find significant association between consumption of processed meat andasthma control. We then focused on the potential protective role of a specific nutrient, dietaryfiber, on respiratory health. The analyses showed that higher intakes of dietary fiber, mostlyinsoluble fiber and fiber from cereals, were associated with fewer asthma symptoms andgreater asthma control.In the second part of the thesis, we studied the associations between overall diet assessed bydifferent diet scores and respiratory health. The analyses showed that healthier diet assessedby dietary scores such as AHEI-2010 (Alternative Healthy Eating Index-2010), MEDI-LITE(Literature-based adherence score to the Mediterranean diet) and mPNNS-GS (modifiedProgramme National Nutrition Santé-Guideline Score) was positively associated with fewerasthma symptoms and better asthma control. The analyses also showed that unhealthy foodchoices as reflected by a high FSAm-NPS DI (corresponding to the consumption of lowernutritional quality ranked for foods on the Front-of-Pack Nutri-Score scale), were associatedwith greater asthma symptoms. The association between the FSAm NPS-DI score and asthmacontrol was not significant.These work confirm the harmful effect of processed meat consumption and the protective roleof dietary fiber on respiratory health and reinforce the relevance of existing recommendations 6on the beneficial role of a healthy diet for health (and the relevance of the Nutri-Score), andextend its importance for primary and secondary prevention of asthma.