Despite growing evidence suggesting a potential health benefit of high fibre intake for the prevention of chronic inflammatory diseases, studies regarding the role of total dietary fibre intake, types and sources of fibre on asthma are lacking. The present study aimed to investigate the cross-sectional association of dietary fibre intakes and source of fibre with the asthma symptom score and asthma control. A total of 35 380 participants from the NutriNet-Santé cohort were included. Asthma was defined by the asthma symptom score and asthma control by the asthma control test. Fibre intake (g/d) was categorised according to sex-specific quintiles. Multi-adjusted negative binomial regressions were used to evaluate the association between dietary fibre with the asthma symptom score and logistic regressions with asthma control. Participants were aged on average 54 years. After adjustment for confounders, higher intake of total, soluble, insoluble fibres from cereals, fruit and seeds were significantly negatively associated with the asthma symptom score both among women and men; OR for the highest quintile of total dietary fibre compared with the lowest quintile were 0·73 (95 % CI 0·67, 0·79) in women and 0·63 (95 % CI 0·55, 0·73) in men. We also found inverse significant associations between total, soluble and insoluble fibre with uncontrolled asthma; OR for participants in the highest quintile of total dietary fibre was 0·72 (95 % CI 0·55, 0·95) in women and 0·45 (95 % CI 0·26, 0·79) in men. Our results suggested that higher intake of dietary fibre, mostly insoluble fibre and fibre from cereals, was associated with fewer asthma symptoms and greater asthma control.

The role of diet in asthma is still debated. In France, a front-of-pack (FOP) nutrition label based on a modified Food Standards Agency Nutrient Profiling System/High Council for Public Health (FSAm-NPS/HCSP) has recently been implemented to help consumers to make healthier food choices during purchase. At the individual level, the FSAm-NPS dietary index (DI) has been shown to reflect the nutritional quality of the diet. The aim of the present study was to investigate the association between the FSAm-NPS DI and the asthma symptom score. In total, 34 323 participants (25 823 women and 8500 men) from the NutriNet-Santé cohort were included. The overall nutritional quality of the diet was assessed using the FSAm-NPS DI. Increasing FSAm-NPS DI reflects decreasing overall diet quality. Asthma was defined by the asthma symptom score (sum of five questions). Negative binomial regression was used to evaluate the association between the FSA-NPS DI and the asthma symptom score. Overall, mean participant’s age was 54 ± 14 years, and about 27 % reported at least one asthma symptom. We observed a significant positive association between less healthy diet, as expressed by higher FSAm-NPS DI, and the asthma symptom score. The adjusted OR were 1·27 (95 % CI 1·17, 1·38) among women and 1·31 (95 % CI 1·13, 1·53) among men. Unhealthy food choices, as reflected by a higher FSAm-NPS DI, were associated with greater asthma symptoms. These results reinforce the relevance of public health approach to orient consumers towards healthier food choices by using a clear and easy-to-understand FOP nutrition label based on the FSAm-NPS, such as the Nutri-Score.