Background: Although there are several studies on the influence of diet on asthma in schoolchildren, none of them has evaluated how obesity can modify this influence. The objective of the present study is to evaluate the association of various foods and a Mediterranean diet with the prevalence of asthma and rhinoconjunctivitis adjusting for obesity and exercise.
Methods: Cross-sectional study of 20,106 schoolchildren 6-7 years old from 8 Spanish cities. Using the ISAAC phase III questionnaire parents reported chest and nose symptoms, food intake, weight and height, and other factors, including exercise. A Mediterranean diet score was developed. A distinction was made between current occasional asthma (COA) and current severe asthma (CSA).
Results: Independently of the amount of exercise, each Mediterranean score unit had a small but protective effect on CSA in girls (aOR 0.90; CI95% 0.82-0.98). Exercise was a protective factor for COA and rhinoconjunctivitis both for girls and for boys (the more exercise, the more protection). Obesity was a risk factor for CSA again for girls (aOR 2.35; CI95% 1.51- 3.64). Individually, a more frequent intake (1-2 /week and 3+ /week vs. never/occasionally) of seafood (aORs 0.63 [CI95% 0.44-0.91]; 0.53 [CI95% 0.35-0.80]) and cereals (aORs 0.56 [CI95% 0.30-1.02]; 0.39 [CI95% 0.23- 0.68]) were protective factors for CSA, while fast-food was a risk factor (aORs 1.64 [95%CI 1.28-2.10]; 2.26 [CI95% 1.09-4.68]). Seafood (aORs 0.74 [CI95% 0.60- 0.92]; 0.67 [CI95% 0.53-0.85]) and fruit (aORs 0.76 [CI95% 0.60-0.97]; 0.71 [0.57-0.88]) were protective factors for rhinoconjunctivitis.
Conclusions: These results support a potential protective effect of the Mediterranean diet in 6-7 year- old girls with CSA. Obesity is a risk factor for this type of asthma, only in girls.
- Mediterranean diet