Studya and location  Sample and study design  Asthma outcome  Dietary pattern  Primary results  Adjusted confounders  Quality score (rating)b
de Cássia Ribeiro Silva et al41Brazil  n=1,187; 6–12 years; 47% girls; cross-sectional  Current wheezing  PCA: 2 dietary patterns (“prudent” and “Western”); 97-item FFQ  Western pattern was positively associated with wheeze (OR 1.77, 95% CI 1.10–2.84).  Age, sex, education of caregivers, per capita income, number of people living in the household, presence of smokers in the house, BMI, stages of sexual maturity, physical activity, energy intake, the other dietary pattern  8 (positive)
Lee et al43Taiwan, People’s Republic of China  n=2,082; 8.5±1.7 years; 47% girls; cross-sectional  Current asthma, current severe asthma, nocturnal cough, exercise-induced wheeze, ever asthma  RRR: 1 unhealthy dietary pattern; 21-item FFQ  The unhealthy dietary pattern (high consumption of fast foods, high fat snacks, candy, and cheese, low consumption of fruits, vegetables, and rice) was positively associated with current asthma (OR 2.42, 95% CI 1.19–4.93), current severe asthma (OR 4.45, 95% CI 1.59–12.5), and nocturnal cough (OR 1.82, 95% CI 1.07–3.11).  Age, sex, BMI z-score, older sibling number, mother’s education level, parental asthma history, ambient nitrogen oxides concentration, seasonal effect  8 (positive)
Tromp et al32The Netherlands  n=2,173; cohort  Wheezing, shortness of breath at the age of 2, 3, and 4 years  PCA: 2 dietary patterns (“health conscious” and “Western”); 211-item FFQ  Higher adherence to “Western” pattern was positively associated with frequent wheeze (RR 1.39; 95% CI 1.02–1.89) at 3 years of age and frequent shortness of breath (RR 1.44; 95% CI 1.03–2.01) at 4 years of age. These associations were partially explained by energy intake.  Maternal age, maternal socioeconomic status, smoking during pregnancy, parental history of atopy, multiple parities, standard deviation score birth weight, sex, breastfeeding, vitamin D supplementation at 6–12 months, day care attendance in the first 2 years of life, and history of cow’s milk allergy in the first year  9 (positive)
Grigoropoulou et al34Greece  n=1,125; 10–12 years; 53% girls; cross-sectional  Ever asthma (symptoms)  Mediterranean diet; 63-item FFQ  Higher Mediterranean score was associated with a lower prevalence of ever asthma (OR 0.84, 95% CI 0.77–0.91).  Environmental factors (details unknown)  9 (positive)
Gonzalez Barcala et al35Spain  n=14,700: 6–7-year age group, 6.5±0.5 years, 49% girls; 13–14-year group, 13.5±0.5 years; 51% girls; cross-sectional  Prevalence and severity of ever asthma  Mediterranean diet (quartiles); FFQ (number of items unknown)  No protective effect of Mediterranean diet was found.Higher adherence of the diet was associated with a higher risk of severe asthma (OR 2.26, 95% CI 1.21–4.22) in girls aged 6–7 years.  BMI, parental smoking, maternal education  8 (positive)
Romieu et al33Mexico  n=158 asthmatic (mean 9.6 years; 38% girls) and 50 nonasthmatic (mean 9.3 years; 60% girls); cohort  Inflammatory response (IL-8) and lung function (FEV1, FVC)  Fruit and vegetable index and a Mediterranean diet index; 108-item FFQ  In asthmatic children, fruit and vegetable index was negatively associated with IL-8 levels in nasal lavage (P=0.013); Mediterranean diet index was positively associated with FEV1 (P=0.045) and FVC (P=0.018). Fruit and vegetable index was a significant modifier for the effect of ozone on FEV1 (P=0.023) and FVC (P=0.008) and Mediterranean diet was a modifier for the effect of ozone on FVC (P=0.02).  Sex, BMI, previous day minimum temperature, corticoid use, chronological time  8 (positive)
Arvaniti et al36Greece  n=700; 10–12 years; 54% girls; cross-sectional  Ever asthma, asthma symptom, ever wheeze, exercise wheeze  Mediterranean diet; 63-item FFQ  Higher adherence to Mediterranean diet was associated with a lower prevalence of ever asthma, any asthma symptom, ever wheeze, and exercise wheeze (all P<0.005).  Age, sex, BMI, physical activity status, energy intake  8 (positive)
Nagel et al4420 countries  n=50,004; 8–12 years; cross-sectional  Ever asthma, current wheeze, and atopic wheeze  Mediterranean diet; FFQ (number of items unreported)  Higher adherence to Mediterranean diet was associated with a lower prevalence of ever asthma (OR 0.95, 95% CI 0.92–0.99) and current wheezing (OR 0.97, 95% CI 0.94–0.99).  Age, sex, environmental tobacco smoke, parental atopy, exercise, number of siblings  8 (positive)
Castro-Rodriguez et al37Spain  n=1,784; 4.08±0.8 years; cross-sectional  Current wheeze  Mediterranean diet; FFQ (number of items unreported)  Mediterranean diet was a protective factor for current wheezing (OR 0.54, 95% CI 0.33–0.88).  Age, birth weight, livestock during pregnancy, delivery by cesarean, antibiotic consumption during the first year, acetaminophen consumption during the previous 12 months, rhinoconjunctivitis, dermatitis, paternal asthma, maternal asthma, maternal age, maternal education level, current paternal smoking, current maternal smoking, vigorous physical activity frequency, cats at home in the last 12 months  8 (positive)
De Batlle et al42Mexico  n=1,476; 6–7 years; cross-sectional  Ever asthma, ever wheezing, current wheezing  Mediterranean diet; 70-item FFQ  Adherence to Mediterranean diet was negatively associated with ever asthma (OR 0.60, 95% CI 0.40–0.91) and ever wheezing (OR 0.64, 95% CI 0.47–0.87).  Sex, maternal education, exercise, current tobacco smoking at home, maternal asthma, maternal rhinitis  8 (positive)
Chatzi et al38Spain  n=460 children aged 6.5 years; cross-sectional  Persistent wheeze, atopic wheeze  Mediterranean diet; 96-item FFQ  Adherence to Mediterranean diet was not associated with either asthma outcome.  Sex, maternal and paternal asthma, maternal social class and education, BMI, total energy intake  8 (positive)
Chatzi et al39Greece  n=690; 7–18 years; 52% girls; cross-sectional  Current and ever wheezing, wheezing ever with atopy  Mediterranean diet; 58-item FFQ  High adherence to Mediterranean diet was not associated with current and ever wheezing.  Age categories, sex, BMI, parental asthma, number of older siblings  8 (positive)
Garcia-Marcos et al40Spain  n=20,106; 6–7 years; cross-sectional  Current occasional asthma, current severe asthma  Mediterranean diet; 15-item FFQ  Mediterranean diet was a protective factor for current severe asthma in girls (OR 0.90, 95% CI 0.82–0.98).  Older and younger siblings, maternal smoking  8 (positive)
Sanchez-Solis et al19Spain  n=683; 6–8 years; cross-sectional  Clinical significant asthma  Mediterranean diet; 26-item FFQ  Mediterranean diet was a protective factor for clinical significant asthma, independent of percent body fat (OR 0.78, 95% CI 0.61–0.97).  Adjusted, but not specified  NAc